Keith's light weight off roader

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KeithB
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Re: Just found this forum

Post by KeithB » Sat Aug 18, 2018 7:10 pm

I have not done this before on this forum, but here we go. You can see from the dates on the pictures how long this thing has been going.

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I have a string on myswag.org called "World's Slowest Build" but am happy to post some more here if anyone is interested.

Keith

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Re: Just found this forum

Post by Frank & Brenda » Sun Aug 19, 2018 9:17 am

Welcome Keith,
Looks like a great job, if we can access the site it would be great of you to put a link to it here so we can see more of your build

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Re: Just found this forum

Post by KeithB » Sun Aug 19, 2018 10:07 am

Thanks for your interest. Here is the link.
http://www.myswag.org/index.php?topic=27176.0
I am not sure whether you have to sign up to see images. It's free anyhow.
Keith

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Keith's light weight off roader

Post by KeithB » Sun Aug 19, 2018 4:58 pm

Hi everyone. I am new to this forum and have been slowly building a little pop top off roader for the last half dozen years of so. I am trying to make it very comfortable for two and light enough to go over sand dunes.
Here are some specs:

Chassis: Mixture of 100x50x3, 100x50x4, 50x50x3 RHS and 75x75x3 plus some 75x2.7 round.
Running gear: Heavy solid axle with a five link setup, 2,800kg Firestone air bags, two 100 series shockers on each wheel. 33 inch tyres.
Brakes: Landcruiser hubs and disks with electric over hydraulic power. freewheeling hubs with a fixed spline in the axle to act as a parking brake.
Construction material: 15mm thick Polycore which is 1mm glass epoxy over a plastic honeycomb core. Approximately 4kg per sq m. All furniture is bonded to the body and is structural.
Electrics: 1000 watts of thin film solar on the roof, 100 amp MPPT controller, 1.4Kw inverter charger. Two 200AH LiPo4 batteries. 60 amp DC-DC charger.
Hot Water and interior heating: Diesel furnace recirculating coolant to a fan heater and heated towel rail.
Aircon: Very small Toshiba split system
Bed: Queen size sideout at the back
Fridge: 210 litre 12 volt Evakool
Water: 380 litres usable in three tanks which form part of the floor structure. Selectable pumps for each tank. 60 litres grey water.
Toilet: Airhead composting
Cooking: Three burner stove,microwave oven plus slideout Sovereign BBQ
Dimensions & Weights
Body: 1.95m x 4.4m closed. 5.9 long with slideout.
Tare wight dry: Hoping for 1,400kg or less.

Will do a second post to start the pictures.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Sun Aug 19, 2018 5:08 pm

Chassis shots

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Re: Keith's light weight off roader

Post by KeithB » Sun Aug 19, 2018 5:13 pm

Overall Plan

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Water Tanks

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Re: Keith's light weight off roader

Post by KeithB » Tue Aug 21, 2018 3:20 pm

Starting on the body

Getting some walls up

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Gluing the body down

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Re: Keith's light weight off roader

Post by Archer63 » Tue Aug 21, 2018 6:38 pm

Interesting build Keith !
Looking forward to seeing progress reports.

Cheers
Rob
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Re: Keith's light weight off roader

Post by KeithB » Tue Aug 21, 2018 11:01 pm

Thanks Rob.
Keith

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Re: Keith's light weight off roader

Post by Lance » Tue Aug 21, 2018 11:12 pm

Making good progress there Keith.
How long has the build been going ?
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Re: Keith's light weight off roader

Post by KeithB » Wed Aug 22, 2018 6:37 am

Lance,
I started it about seven years ago but have had several breaks of a year or more. I almost gave it away at one stage.
Currently I have the main body painted inside and out, bathroom and kitchen pretty much finished, most of the wiring and plumbing is also done.
I am currently working on the slide out bed at the back, which is far more work than I was expecting. Then I'll have to do the popup roof plus get all of the systems working - electric over brakes, hot water, air suspension system and so on. Will fit the windows, doors and drawbar extension last.
The biggest difficulty with this build has been lack of space.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Wed Aug 22, 2018 11:39 am

Plant locker at the front

I fabbed up a little plant locker on the front of the van to take all the mechanical stuff plus mount the gas bottles.
It houses the electric over hydraulic brake thingy, diesel water heater which also distributes coolant to heaters inside the van, compressor, tank and valves. A standard Camec hatch will be fitted to it.

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There is a 10 litre plastic tank mounted each side for diesel for the water heater. The pink thing there is a piece of high temperature silicone runner to pass the exhaust through.

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Re: Keith's light weight off roader

Post by KeithB » Thu Aug 23, 2018 12:44 pm

Fitting out the inside

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Here you can see the left side bench which contains a locker for a battery (one on the other side too) and a slide out BBQ. The black louvres are for a fan heater and it's air inlet and the hoses are for coolant to and from the heater. The round things are marine hatches for maintenance access for wiring and suspension.

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Here's a start on the bathroom at the front with a test fit of the Airhead composting toilet. You can also see the coolant hoses and hidden underneath are the hydraulic brake lines. The white PVC pipe is the drain from the sink into the grey water tank.

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Shower recess underway. I later used epoxy resin to get a fall to the floor waste which has its own pump to the grey water tank.

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Here's the kitchen in its early stages with panels doubled up for the benchtop.

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Re: Keith's light weight off roader

Post by KeithB » Sat Aug 25, 2018 9:55 am

Exterior Paint

This composite material has a linen-like finish with pockmarks in it. I put three coats of primer on both sides of each of 15 3.3x2m panels and sanded them off before starting the build (a huge job) but it didn't fix the problem. So I went over the body with some thin blue epoxy fairing compound which you can see here before and after sanding with 60-120-220 grit.

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I found out late in the piece that this composite material will allow light to shine through - in or out. So I put on half a dozen coats of black to act as a final primer and went over it with half a dozen coats of white.

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I am rolling on a water based two pack polyurethane boat paint to keep the fumes down and to minimise cleanup problems. It's as dear as poison, not easy to use and I found multiple thin coats works best. On the plus side, it is compatible with epoxy glues, resins and fillers. The best part about it is that it dries rock hard and can be easily buffed it you're keen enough. I'm not. I think it should hold up well on the road.

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Re: Keith's light weight off roader

Post by J.REEVES » Sat Aug 25, 2018 7:51 pm

Hi Keith,
Welcome to the forum.
Your build has certainly got some different approaches to normal caravan construction.
Chassis and suspension looks great. The water tank system is very different and innovative.

If you have seen any of my posts I am often a bit negative so a couple of suggestions but it does look like you know exactly what you are doing.

I like your shock absorber set up but consider fitting adjustable shocks. I found that when I took my van for its first run with very similar air bags I noticed the van was swaying a little. As I used Koni adjustable shocks it only took a small adjustment to fix the problem, so consider adjustable shocks.

1000watts of solar and two 200AH lithium batteries you certainly have the power requirements covered. 1500watt inverter in my opinion is a little small considering the battery power you have. At some stage you may decide to have a coffee machine or microwave and you may even decide to use an electric toaster when you find all the gas toasters are not that good. So consider upping the inverter to 2500 to 3000watts to cover these things and give a little room so the inverter is not running at its top end.

Looking forward to follow your build.

JR
:razz:

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Re: Keith's light weight off roader

Post by KeithB » Sun Aug 26, 2018 9:07 am

Thanks for the encouragement JR. The shocks I put in are second hand from a 100 Series Landcruiser just as a starting point. The roll centre with this axle setup is much higher than, say, independent trailing arms and I am expecting less body roll. I used them because of their availability and because they have good internal bump stops so I don't need straps to protect the air bags.

I went with the 1.4 Kw inverter charger knowing that I wouldn't be able to run, say, the aircon and the microwave at the same time. It was a compromise between cost, weight and space availability, as you'll see from the pictures. It will charge at 70 amps when connected to the mains and, if the mains source is dodgy, I can set a maximum current limit from the mains and and intermittent peak loads will come from the battery. It's a smart bit of gear.

The two big items are the 1.4 kVA inverter-charger and the 100 amp solar controller. I glassed a couple of bits of hardwood onto the wall behind the (yet to be built) kitchen draws and screwed the inverter–charger onto that. There wasn’t room on the back wall for the solar controller, so I mounted that on stilts on the floor to give space to get a bit of air under it. To get to all of the electrics and pumps you just slide out the draws for access.
The two pictures below show the setup front on and from above. The kitchen draws need to be removed for maintenance access, but they will have enough clearance to allow air movement.

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To the left on the back wall is a 60 amp DC-DC charger. At the bottom right are three thermostaticly controlled computer cooling fans. One goes on whenever there is voltage from the solar panels and the others come on if the top of the cabinet hits 40 degrees. They draw very little current. I have yet to tie down all of the cables because there is a still a bit more wiring to do.

Here is the the back of the control panel before the Inverter Charger control panel went in. I've got all of the wires labelled to avoid later confusion.

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Below is a shot of the starboard side locker which will contain one of the two house batteries. With the wisdom of hindsight, I pulled out the cables from there to the inverter charger and replaced them with the heaviest I could get. They emerge from top right. Top left you can see smaller cables which run through the chassis to the battery compartment on the other side. There is also a 300 amp fuse to keep things honest and an isolation switch which cuts all power. The thing with the coiled up wire attached to it is the shunt for the battery condition monitor, which will be located up in the kitchen.

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I'll explain all of the plumbing in another post.

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Re: Keith's light weight off roader

Post by J.REEVES » Sun Aug 26, 2018 9:59 am

Yes I have trailing arm suspension and it is in quite some distance in from the sides where it is supported so you may not have an issue.

You have not compromised with your electrics a very impressive set up!
I only have a cheap inverter not a quality Victron. In fact I am considering buying a spare inverter as I don’t expect the cheapy will last too long.

JR
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Re: Keith's light weight off roader

Post by KeithB » Sun Aug 26, 2018 10:38 am

I have an old friend helping me who has a sizeable marine electronics business. Does superyachts as well as smaller boats a all over the country. He helped me with equipment selection and got it for me at mates rates. But it was still expensive. I know that trailing arm suspension is all the range and most folks just love it. but I don't. Or maybe it's just me being old and grumpy.

I had trailing arm suspension on a camper trailer and it was fine - until it went out of alignment and began chewing out tyres. In fact it's usually great on light trailers, except that all of the load is on bushes which need to be replaced or adjusted to maintain the alignment. But I can't understand why everyone is so keen on it for caravans. The body roll comes from the geometry of the suspension itself and placing the springs inboard to keep the height down makes things even worse. Then they add insult to injury by putting the shockers at a silly angle which makes them work 50% harder than they should.

Why anyone would need independent suspension on a single axle caravan I just don't know. On tandems they are almost always not load sharing, which is a problem in my view. I remember seeing an accident report where a tandem was being towed nose down, which caused a fatal accident as the tail began to wag the dog.

Collyn Rivers, a man for whom I have great respect, is quite critical of this type of suspension on heavy vans - particularly ones with a lot of weight on the back. I guess it's just a fashion - like checkerplate all over the place, which we all know is even stronger if you paint it black.

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Re: Keith's light weight off roader

Post by JackDriver » Sun Aug 26, 2018 11:29 am

Mate, love your work. Also good to find someone who appreciates the deficiencies of tandem trailing arm coil suspension, with the inherent low roll centre and lack of load sharing. Just love how you positioned your shocks to get them to work properly as most are on ridiculous angles which makes them a lot harder to achieve the same result.

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Re: Keith's light weight off roader

Post by KeithB » Sun Aug 26, 2018 11:41 am

Jack, you are dead right. Kimberly (may they rest in piece) and Bruder solved the load sharing problem with interconnected air bags. But that does not address the problem of the low roll centre. Some put anti-sway bars in to correct the inherent body roll problem that comes with this flawed suspension design.

Collyn Rivers has written a lot on caravan stability. Here's what he has to say on roll centres and various suspensions if anyone is interested.
https://www.exploroz.com/Vehicle/Carava ... amics.aspx

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Re: Keith's light weight off roader

Post by PeterInSa » Sun Aug 26, 2018 12:19 pm

Keith, Bloody Good Effort and looks a solid van. We take our Traveller Caravan off road, but am not keen on a lot of corrugations. We also have a Mercedes Long Wheel Base Sprinter Campervan, cupboards are thin Ply with wood around the edges for strength and support, ditto the cover of the interior walls. This is an area that to me you will gain some/a lot of weight so will be interested in your your final Tare against your expected calculations. Note we do not take the Sprinter Off road.

Peter

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Re: Keith's light weight off roader

Post by KeithB » Mon Aug 27, 2018 9:58 am

Peter, all my walls and structures are composite. Any weight gains I think will come from all the little odds and ends that come in at the last minute. But I am hoping for under 1,400Kg dry weight. We'll see.

Plumbing

I got a little ahead of myself with the last post because the plumbing went in before the electrical bits. Here's a shot of the plumbing under the sink.

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And a closer look.

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There is one pump for each tank which can be selected from the breaker panel. Each pump has a suction strainer and flow meter. They all discharge through a single BEST filter. The water tank gauges are on the fascia in front of the sink.

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Here's what the shower pump looks like. It's a Flojet the same as the others with two strainers side by side and a non-return valve which you can't see. It discharges into the sink S-bend, same as a dishwasher. It pulls the water from the shower floor waste.

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Re: Keith's light weight off roader

Post by J.REEVES » Tue Aug 28, 2018 4:10 pm

Hi again Keith,
Well you just struck a nerve with your comment: Why anyone would need independent suspension on a single axle caravan I just don't know.
The Neville Withers (Suger Glider) trailing arm suspension on my 2.7tonne single axle van is in my opinion as good as it gets. Neville made me a special 3.3tonne rated suspension and he uses Vesconite bushes which on inspection after 80,000Km still required me to use a dolly to tap the sleeve out.
I am not sure what trailing arm was on your trailer but usually the bushes just hold the arm in position and the weight is on the air bag or coil spring.
I have had some discussion with Collyn Rivers on a forum and yes it was clear he did not like trailing arm and air bags but in my view he was more into GT cars going around corners.

All a caravan suspension needs to do is track well, ride softly and that soft suspension needs to be controlled.

Body roll is not really important (within reason), having the support as close the wheels is good and would reduce body roll. Trailing arm does help ground clearance down the centre which I have found helpful and being independent also must contribute to the ride quality.
I have just travel 2500Kms of very rough roads and the trailing arm suspension has been the savior for my van as we have not sustained any form of damage from corrugations and the like but seen many with big problems.

Trailing arm suspension on a single axle van using air bags is good stuff.

Yes the checker plate makes the van strong and then paint it black and it is bullet proof, another thing make it as high of the ground as possible and don’t fit any steps.

JR
:razz:

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Re: Keith's light weight off roader

Post by KeithB » Tue Aug 28, 2018 5:53 pm

John, I did my mouthing off about independent trailing arm suspension before I had read your build thread. Yours is a wonderful build and I apologise if I offended you. My independent suspension was on a crappy Chinese camper, which may have jaundiced my view more than a little.

From my reading, every caravan has a critical speed above which it can become unstable if it cops a major disturbance. A lower roll centre lowers that critical speed. So does a high polar moment of inertia which is what happens when all the weight is in the front and the back, producing a dumbell effect. Independent training arms track perfectly because they avoid bump steer; that's their big plus and yours is an excellent and well engineered example. They also ride well if the springs and dampers are properly matched; but so do all suspensions. There are many threads on other forums where, like me, people can't get their wheels to stay in alignment.

But I think a properly engineered sold axle gives the best of both worlds - a high roll centre and freedom from bump steer. On a single axle I don't think independent suspension of itself is essentially necessary because the caravan is supported at just three points. But I would have independent suspension over a poorly designed solid axle leaf any day. I have had lunch and much correspondence with Collyn Rivers and he is very much into and passionate about caravan stability.

By the way, I liked your words about LiPo4 batteries. You must have been one of the first to adopt them. Are you still happy with them? I am looking at sourcing two 200 AH ones from EV Power as well. They have been very helpful over the phone.

Sorry if my words annoyed you.

Keith

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Re: Keith's light weight off roader

Post by J.REEVES » Tue Aug 28, 2018 8:35 pm

Hi Keith,
No it’s OK I have problems with theory and my experience at times I find experience or been there done that can be blanketed with theory and calcs and it’s a bit difficult to argue against high polar moment of inertia dumbbell or pendulum effect.

I remember the first time I hit a big bump with the van and felt nothing come from the van, I then looked at my rear camera monitor as if I was looking at my rear vision mirror and just for a spit second I thought the van had gone as all I could see was the road behind me. Almost no feeling from buffer when large trucks go past in the other direction.

Well you would certainly know Collyn Rivers much better than my small forum conversations. Does Collyn Rivers have a caravan with a suspension like he would design?

The lithium is just such a big step from lead acid. My 200AH lithium is now over four years old and performing perfectly so could recommend lithium to anyone.
Almost every day on this current trip we have used our 1500watt coffee machine and the lithium does not show any sign of the load it is experiencing.

JR
:razz:

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Re: Keith's light weight off roader

Post by KeithB » Wed Aug 29, 2018 3:41 pm

John, Collyn has a lot of off road experience. As a young man he went touring all around Africa in an old truck that they had to constantly fix. He gave me a DVD of the adventure. Since then he has done a lot of touring off road in Australia, I think mostly with a TVan. He's not a young man by any means but is incredibly fit in body and mind. He is also a Yoga expert.

I think your suspension is very well designed. If you look at the drawings you posted, it is clear that there is a huge amount of weight on the bushes because if the bending moment from the wheel.

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But your bushes have obviously been properly designed and are trouble free. No so my caravan bathroon.

The Bathroom

This build has a very tiny bathroom, only about 700mm wide. But at least the shower and toilet are separate. Here's the side with the composting toilet.

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The shiny thing on the left is a heated towel rail which should also keep the bathroom warm and dry. I built it mostly myself and had it professionally polished. Coolant enters and leaves from the bottom at either side. The black vents top and bottom are for the 12 volt fridge. The lower one conceals a whole load of wiring. More about the fridge in a minute.

The composting toilet has a little fan that runs continuously and draws very little current. I have put a 3 inch centrifugal on there in series for when the loo is being used - to keep the thing under heavy suction so that the air stays fresh. Here's a close-up if the arrangement.

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On the other side we have the shower. The duct you can see is yet to be closed up. It carries all the wiring to be used above kitchen bench height.

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I have finished the internal painting, but it will need a final coat right at the end as it is bound to get damaged. There are four computer fans in the top rear of the fridge cabinet that exhaust into the bathroom. They are controlled by a thermostat mounted on the fridge compressor. It's set to come on at 40 degrees. Here's the Evakool 210 litre fridge in situ with the bathroom door shown closed.

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I got some LED light strips from Jaycar and installed them concealed under the pelmets which are structural parts of the caravan.

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Next comes a few odds and ends plus the pullout bed and we will be up to date.

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Re: Keith's light weight off roader

Post by KeithB » Sun Sep 02, 2018 2:25 pm

The dreaded Slide-out bed

Not shown on the earlier plan is the dreaded slid-out bed. I say "dreaded" because the thing has been a total pain in the bum to get working. It started by installing two 227Kg slides.

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Next came fabbing up a base box for the slides to mount onto. The extra drawer slides inside the box are for storage drawers.

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The the bed base.

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Next came some walls and a roof.

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Next came the rear wall of the slideout.

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Looks like I'be reached my picture limit, so time for a new thread.

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Re: Keith's light weight off roader

Post by KeithB » Sun Sep 02, 2018 2:38 pm

More on the dreaded slide-out bed.

I had to pull this apart and relocate bolts and other fixings to get the thing to work. Here are the interior metal drawers that I had fabbed up. They original ones were made oversize and had to be replaced. They are for clothes and stuff and are 900mm deep.

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It immediately became apparent that the slides were inadequate, despite their claimed 227 Kg loading. They wobbled side to side and sagged a couple of inches with no load in them. What to do?

Doe to some disportion during galvanising, the rear posts came forward a little bit, which meant that the gate at the back slopes upward when it is opened. You can see that by comparinmg it to the brickwork behind it.

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So, after much help and advice from the guys on Myswag, I came up with this roller system.

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The gate post is tied back into the body with some angle and the roller supports the full weight of the sleeper. Tested with 80Kg in the back of the sleeper it sagged only a few millimetres.
By adding a couple of telescopic poles either side, it was perfectly steady. The poles will go in a pole holder inthe chassis.

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Re: Keith's light weight off roader

Post by KeithB » Sun Sep 02, 2018 2:54 pm

Mounting the Aircon

I was originally going to lose one of the spare tyres (there are already two on the tow) and put the aircon compressor unit on the rear gate. But diffiulties finding suitable flexible hose plus other complications meant I should mount it on the rear wall of the slide-out. So I decided to double skin the rear wall to stiffen it up a bit.

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The Sleeper is too short for a full length bed, so the bed will concertina into a day bed, which can be stretched out at light, taking up about 50cm of the saloon space. The means that I can't have a whole load of aircon bolts coming through the back wall. So I buried a bunch of 10mm stainless steel Tee nuts into the double skinned wall. Here's a closeup.

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And here is the rear wall with the aircon support bracket dry fitted.

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I added a bit or material to the inside of the sleeper to stiffen it up a bit and dry fitted the aircon evaporator.

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Also fitted some rubber wheel arch flares

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And a picnic table.

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So now we are up to real time and future posts will be fewer and further between. Such is the nature of this very slow build.

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Re: Keith's light weight off roader

Post by PeterD » Sun Sep 02, 2018 5:08 pm

J.REEVES wrote:
Tue Aug 28, 2018 4:10 pm
I have had some discussion with Collyn Rivers on a forum and yes it was clear he did not like trailing arm and air bags but in my view he was more into GT cars going around corners.
When Collyn was working on suspensions he was working on Vauxhall cars. That is a far cry from GT cars. If you want to see what he thinks then purchase his "The Camper Trailer Book." I have just looked at the second edition. He seems to be supportive of AlKo rubber suspension which has not got a mention here.

As for "bump steer" it is only of any great importance where wheels are pivoted at the ends of the axle (steering axles.) Gyroscopic action does not affect the tracking of a wheel when it is firmly attached to an axle.
PeterD
Retired radio & electronics technician -
Nissan Navara D40 diesel auto (pensioners pack) towing a Spaceland pop-top

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Re: Keith's light weight off roader

Post by KeithB » Sun Sep 02, 2018 8:02 pm

Peter I was thinking of a solid axle with short eliptical leaf springs, which are very common on trailers and used to be common on caravans. When the spring is compressed, it flattens out a bit and that side of the axle moves back a touch. So the trailer steers momentarily into the direction of the bump. Modern utes all have very long leaves which are almost flat under load, so bump steer is not a problem.
There is an earlier link in this string to Collyn's pieces on trailer suspension which I think are more detailed than his book. His book is good though and I learned a lot from it.

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Re: Keith's light weight off roader

Post by jailbar joe » Mon Sep 10, 2018 9:23 pm

wow interestin build keith...just read most of the thread and trying to absorb as much as i can before continuing.........

trying to get my head around the plumbing and electrics as i will be going down this path soooonish but for now reading as many builds as i can...

a lot of very innovative ideas in there and i can relate to the amount of work that goes into it all......very time consuming.

i'm sure you will enjoy it very much thanks for posting in such detail
cheers
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Re: Keith's light weight off roader

Post by KeithB » Thu Sep 13, 2018 5:19 pm

Joe thanks for your kind remarks.

This build started on Myswag where there is a lot more detail. But now that we are up to date, I'll duplicate all posts here.

The Fold-Down bed in the Slide-out Sleeper


You may recall that the slide-out sleeper is too short for a full length bed. So the plan is to have a hinged bed that partly folds up against the rear wall of the sleeper to form a sort of double chaise when it is not extended out as a bed.

So we started out with two sheets of composite which had to be reinforced with a bit of timber to make the thing a bit more rigid and to provide some anchorage for the various attachments. Here it is shown from the underside with almost all of the rollers attached.

Image

There's a big stainless steel piano hinge in there which I have secured with a heap of 6mm Tee nuts so that everything clears okay. The rollers came from the UK and are just 15mm high and are rated at 35 Kg.

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I looked at a whole lot of methods to get the bed up and down - air lifters, a winch, air springs and so on. but in the interests of cost, weight and simplicity, I settled on a bit of rope.

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Here's a shot of the bed base in the retracted position with the oversized rope yet to be trimmed. The base board is to stop the yet to be sourced mattress from sliding forward.

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And here is the "Hi-Tech" retaining mechanism for the rope.

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To release it, you just flick the rope out between the cleat and the pulley at the top. Here's a shot of the bed in the up position with the slid-out pulled fully in.

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Ops I've got too many pictures. So I'll start a new post.

There's enough room to get about the kitchen and access the dunny plus room for one person to sit down or two to relax on the folded up bed. Here's what it looks like with the slider out and the bed fully extended.

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Re: Keith's light weight off roader

Post by KeithB » Thu Sep 13, 2018 5:25 pm

Where were we? Here's what it looks like with the slider out and the bed fully extended.

Image

This leaves room for three or four people at the dinette. To pull the bed up, you currently kneel on the half of the bed closest to the kitchen and pull horizontally on the rope. This simultaneously lifts the back of the bed and moves the base towards the back wall. Not easily seen in the pictures are a couple of timber tabs located high on the side walls to hold the elevated back of the bed in position. The back of the bed slides tightly behind them as it goes up.

You can see some aluminium angles at each side which stop the bed tipping if you sit on the end when it is fully extended. It flexes a little, but is quite acceptable.

We now have to take the bed base out, fit come catches to hold in in place and fair and paint the whole slide-out. I have a mate who has taken pity on me and has offered to come and help, which I really appreciate.

Keith

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Re: Keith's light weight off roader

Post by jailbar joe » Sat Sep 15, 2018 9:31 pm

again....very impressive and thanks for taking the time to show and explain the features.....i am sure there is a lot of head scratching going on there....
makes my little project seem easy peasy...but...as easy as it has been i have had a lot of headaches also :roll:

i look forward to seeing how it all comes together but for now am happy to follow along.
cheers
joe


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Re: Keith's light weight off roader

Post by KeithB » Sat Sep 15, 2018 9:49 pm

Joe I just read through your build thread and it looks anything but easy peasy. Building anything on your own can be very lonely and it's great to hook up with fellow builders on forums like this one to get a bit of encouragement and some help with difficult questions.
Keep plugging away at it mate. Mine's been going, off and on, for about six or seven years and I've almost given it away a couple of times.
Keith

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Re: Keith's light weight off roader

Post by J.REEVES » Mon Sep 17, 2018 11:26 am

Hi Keith,
Just checked the spare proximity switch, the switch and the magnet are completely sealed.
The gap to allow the spade to pass through is 14mm.

I think they are now superseded as I cannot find them on the net the ones I have are about 15years old.
Prox.JPG
Prox open.JPG
JR
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Re: Keith's light weight off roader

Post by KeithB » Mon Sep 17, 2018 3:50 pm

Thanks John. I'd like to put two each side - one for road height and one for off road height.
I have emailed the outfit named on your sensors so we'll see what happens. Just doing a search, there are also a lot of waterproof reed switches available at just a few bucks each, rather than the $160+ for ones like yours - which I think may be even dearer than that, looking at the quality.
But this light setup of yours is simple but elegant and I do appreciate your help on this.
On other matters, I looked at the brake-pressure-wheel diameter table on the early pages of your thread and went into panic mode. I have 33 inch tyres and 13 inch hydraulic disks. Hydrastar sold me a 1000 psi unit as the right thing for the job. I double checked with them this morning and they are adamant that this unit will be okay for 3 tonnes on a single axle with my setup. Phew!
Thanks again John. It's wonderful to see how many folks you have helped on this forum.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Fri Sep 21, 2018 5:37 pm

Now comes the expensive bit.

It looks like we are now entering the most expensive and most awkward part of the World’s Slowest Build. Expensive because it’s getting time for the rest of the big ticket items. Awkward because we are running out of space.

The Sovereign marine BBQ arrived today with its build-in-slide-out kit and I have to say it’s very well made. Mind you at a shade under $1,500, I suppose it should be. The marine grade is the only type they make in that size these days. I can’t fit a Weber in there and the Weber doesn’t come with a containment box and slide-out kit like the Sovereign, so it will save a lot of time. Since we will be using the BBQ all the time I decided to shell out on something good. We’ll see.

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The problem now is that there is the bloody steel post is in front of where the BBQ is to be installed, which has been a pain since Day One. So I have to move the caravan back to allow access to that side of the van to fit the barbie.

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I had the caravan on Supacheap Auto dolly wheels earlier. But I’ve got it down so low now to clear the roof beams that the dolly wheels won’t fit under any more. So I have had to shell out $330 for some 750Kg industrial rollers so that I can move the caravan out a bit. I’ll sell them after the build.

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But I think the van going to hit the roller shutter before I can get it back far enough. So I have contacted a local roller door repair guy to come out and remove it. It was going anyway but now it’s a bit earlier than planned. I’ll take the bulkhead above it out too. The roller shutters are on their last legs and we’d already planned to replace them after the build.

The split bed base is ready to go and we’re getting stuck in to fairing and painting the slide-out bed compartment, which should take a couple of weeks at the rate I work. There are some more big ticket items coming up as well, adding up to over $17K. Here are my guestimates.

Three BFG KO2’s 33’s to match the tow $1,200
Split mattress $1,250
Canvas $3,500
Upholstery and floor covering $2,500
990 watts of solar $3,000
Two 200AH batteries $3,500
Awning $2,500
I hate to think what a similarly spec’d van as light as this would cost commercially. That’s what I keep telling myself anyway.

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Re: Keith's light weight off roader

Post by KeithB » Sun Sep 23, 2018 5:56 pm

I got the Sovereign BBQ in today. But the bulk and weight were a bit of a dissapointment. The company does not publish weights and I went ahead anyhow because there was no other option. Anyhow I weighed it this morning and, with all the build-in kit, it came in at a massive 27Kg. I have budgeted for 8kg.

It takes up a lot more of the compartment than I imagined. By the time I allowed space to get maintenance access to some nuts and bolts plus clearance for electrical cables, there is not enough room for the second 200 AH battery. So It looks like we'll put a 400AH on the opposite locker. It shouldn't upset the balance too much, if at all.

Here it is installed waiting for me to do the gasfitting. I am waiting on some brass fittings. With wheels on and the suspension at running height the cooking surface will come up another 350mm which should be comfortable enough.

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And here with are with the door shut

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I'll have to put some protection in to stop gravel coming off the wheel from pulverising the plastic door.

I spent much of yesterday with my computer design bloke, who is absolutely fantastic. We had the little sidewalls of the roof cut and, after spending an afternoon routing them out it was evident that we had made a blue. There is not enough room to fold the poptop canvas in and no space at all to add stiffening members into the roof. I had forgotten that I am going to have to climb up there to get the solar panels in, so it needs to be able to take a bit of weight.

Anyhow, we redid the side walls of the roof to give a nice continuous curve plus clearance for the canvass. We'll get those machined in the next week or so. We also took some levels and checked that we can get it out on to the driveway when the time comes. Looks like we have 40mm clearance.

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Re: Keith's light weight off roader

Post by Archer63 » Sun Sep 23, 2018 6:31 pm

Onwards and upwards hey Keith 👍
2018 Pajero Exceed
2013 Jayco Swan Outback

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Re: Keith's light weight off roader

Post by KeithB » Mon Sep 24, 2018 10:54 pm

Thanks Archer.

There has not been a lot of "onwards and upwards" on this build. More like "two steps forward and one step back".
The latest step back is the gate at the back which supports the slide-out bed, something that it was never intended to do. It's starting to sag a little and is getting harder and harder to close.

Image

So I'll have to jack it up and weld in some diagonal bracing. Lucky it's only a small step back.
Keith.

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Re: Keith's light weight off roader

Post by KeithB » Tue Sep 25, 2018 5:01 pm

Today I plumbed in the BBQ but got the wrong gas hose. So I will connect and leak test tomorrow or Thursday. Here is the gas bottle setup with two new galvanised gas bottles. The Swap n Go ones are all different sizes and it's much cheaper to get a refill of your own cylinder. It's a pain in the city, but easily done in the bush.

Image

My mate Sean came around today to help out with some more sanding. As a spray painter by trade, he has a terrific touch with the fairing compound - does it much better than I can. Thanks Sean.

Image

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Re: Keith's light weight off roader

Post by KeithB » Fri Sep 28, 2018 12:51 pm

Ordered two 200AH LiPO4 batteries today, with battery management system, due to arrive mid next month. They will go on the starboard side as there is not enough room on the other side after the BBQ went in. But there is room for an extra 100AH on that side if we need it in the future. I will put the spare tyre on the same side as the BBQ to even up the weight on the wheels.

I also went down to see my marine sparky mate about the giant sized wiring loom that came with the diesel water heater. He is going to shorten it up for me. I could have done it myself but am not confident that I would get every one of the dozens of connections perfect. He said he had to do a similar thing on his own motorhome. He also said that, in his opinion, a heated towel rail is an absolute necessity on the road. And here was me thinking I was a bit over the top putting one in.

Finally have the BBQ connected to gas and it works a treat. Lights easily and heats up very fast. Expensive but good.

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Re: Keith's light weight off roader

Post by J.REEVES » Fri Sep 28, 2018 3:42 pm

Hi Keith,
Looking good that BBQ must be one hell of a BBQ for almost $1500.

Yes refilling gas bottles is starting to be a bit of a pain. Looks like you have a gas bottle clamping system that would handle the different size swop and go.

I still have my own gas bottles but must admit it is not as easy as it used to be to get them filled. Often caravan parks are set up to do refills but are not the cheapest places to get them filled. Almost every second petrol station had gas bottle fills but now with almost no staff and the cost of training people that leave anyway it is slowly killing the old refill system at petrol stations. We use an APP on the phone to find refilling stations as they are not that easy to find anywhere.

Is that extra length of wires for the diesel HWS going to make much difference to the weight?
I found it easy enough to roll up the excess wire on my diesel heater and tuck away.

JR
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Re: Keith's light weight off roader

Post by KeithB » Fri Sep 28, 2018 7:01 pm

John, the whole equipment shooting match is in the little front locker which I am afraid to say I have made a wee bit too small. We have the diesel furnace with muffler, exhaust and coolant reservoir, valves and pipes to regulate same in there , compressor and air tank with air controls for the suspension, plus the electric over hydraulic brake unit, plumbing to and external water tap, air vents and a separate vent for the grey water tank. It will all just fit in but there is no room for yards and yards of redundant wiring loom. The loom doesn't weigh much; just takes up unnecessary space.

We won't be using much gas at all - cooking only and we'll fill up when we are in major towns I guess. Swap 'n Go came in because, with only one console operator at the servo at any time, filling cylinders was a bit of a security risk. I think the bloke who started it, who I knew quite well at the time, sold out some years ago to Elgas for a reputed $20 million and it looks like Egas has hiked its prices to get their $20 million back. For me, the real reason for the gal bottles is that they look smarter and don't chip and rust like the S&G ones seem to do. I'll need to put padlocks on them though.

Yep the BBQ is a bit of an extravagance. But it's very well made and is all in 316 stainless so it will outlast the caravan and probably me as well. I wanted it enclosed in its own container because the locker that houses it is vented into the living area for the sake of the batteries. I didn't want BBQ smells coming in. My wife is mad about BBQing lamb, which tastes great but leaves a fat residue that always smells awful the next day. That's my story and I'm sticking to it. Years ago I had a business that manufactured indoor BBQs (went broke of course) and the quality of the Sovereign marine units really appealed to to the old engineer me.

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Re: Keith's light weight off roader

Post by KeithB » Fri Oct 12, 2018 5:05 pm

More stuff has been arriving

The two 200AH Lithium batteries arrived this morning together with the requisite battery management system. They weight a hefty 27Kg each but are about 180Kg lighter than doing the same thing with AGMs.

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Will see about fitting them next week.

During the last week or so the interior of the sleeper has been faired and sanded ready for paint, thanks to my friend Sean. There’s no picture because it looks exactly the same as it did before. The next step there is to get a few coats of black paint on the interior to keep the light out. Then come several finishing coats of off white plus a bit of wiring for lights and the aircon at the back. After that we start work on the outside of the sleeper.

I have had the side walls of the roof recut to the correct size, routed out the edges on my little routing jig and, with Sean’s help, filled them very roughly with epoxy putty. They look crappy right now, but after sanding they will look fine and be ready to test fit in a few days.

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Two bilge blowers and two K&N re-cleanable filters 9 inch long x 7 inch diameter also turned up this week. These will fit under a yet to be built cowling on the roof at the front and will exhaust into the bathroom to pressurise the camper to keep the dust from creeping through the yards and yards of seals. The fans will switch on from the dash on the tow and will be used only on very dusty roads. For most other roads the pressure from the air scoop at anything over 60 kph will, I hope, be enough. These are cheap and nasty blowers but are all that will fit and I expect to be replacing them every few years.

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Last but not least, the WiTi unit has arrived as well. This gives a wireless connection between the camper and the tow with a claimed 30 metre range and does away with the need for a trailer plug. The only place I can fit a plug on my truck is at the base of the rear skirt. It always gets battered with a lot of stones which has caused a lot of problems in the past. This has done away with that but still leaves the Anderson plug and breakaway switch. The unit also has a waterproof motorcycle horn as an alarm which will go off if the van is moved when the alarm is activated. It also locks up the brakes and starts all the lights flashing.

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I have run the fuel lines inside of the little locker at the front of the camper. But there is no way I can fit any wiring in there and still get reasonable maintenance access. So I bought a little 6 inch x 9 inch plastic electrical enclosure and will mount all of the wiring externally. I have almost finished the distribution board for that and will post some pictures next week.

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Re: Keith's light weight off roader

Post by J.REEVES » Fri Oct 12, 2018 6:15 pm

Hi Keith,
That wireless interface certainly sounds like a great product. I must be losing it as I did not know such a thing existed. I know when we go on bad roads I slide a second sleeve over the wire cable to protect it from the stones but your system is far better.

Batteries look great and you won’t be sorry you went to lithium. I notice there is a Perspex cover over the battery terminals which is almost essential as I personally have accidentally shorted two of the terminals with a spanner and the electrical splash was enormous.

Having your pressure system pickup at the front and up at the top is about the best location. Mine is about half way down the van and on my last trip I found after two days of dirt I needed to clean the filter. Using two should make things even better.

JR
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Re: Keith's light weight off roader

Post by KeithB » Fri Oct 12, 2018 7:00 pm

Thanks John.
I hear you can get 5,000 amps if you short out a Lithium battery. That's terrifying.
I don't have a lot of confidence in the $40 Rule bilge blowers I am using and expect to be changing them fairly regularly. I think they are made to blow out a bilge for five minutes and then have a nice rest.
Here's the link to the WiTi thing which has just been released. I got mine with one extra control circuit to work the dust fans at no extra charge. Nice people top deal with.
https://www.witi.com.au/
Not cheap though but I liked the alarm system that goes with it. If someone pinched my camper after all of this trouble I'd be seriously pissed off.
Keith

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Re: Keith's light weight off roader

Post by J.REEVES » Fri Oct 12, 2018 7:37 pm

I understand what you are saying about that blow motor reliability, I have a similar one and have been thinking it will fail for over 10 years now and the bloody thing is still going. On our last trip it was running about six hours a day for many days at a time in fact it sometimes was running when we were on the bitumen as I had forgot to turn it off. I would walk to the side of the van to see if I could hear it just to be sure it was still working. It failed once due to a loose wire in the 12 pin plug but not the actual blow. I use a relay next to the fan which is switched on from the vehicle via one of the pins in the 12 pin plug.
Actually I have considered buying a spare but my days of dirt and dust will not be as over the top as it has been during the last ten years.

I think the one saviour for the bilge blower motor is that it is the air flow circuit and so has good cooling.

Had a look at the WiTi link nice stuff.

JR
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Re: Keith's light weight off roader

Post by KeithB » Fri Oct 12, 2018 8:09 pm

One of the guys on Myswag said that he's had the same blower on for many years and often runs it for six hours a day. Still going strong. So it looks like yours in no fluke. This is very reassuring. as I had no confidence in them at all
John, with this WiTi thing, I like the fact that you can leave your old 12 pin in place with the WiTi and still be able to tow other trailers. That old trailer plug of mine has been the bane of my life. I am really looking forward to working all of the lights while the camper is in a garage and I am parked on the street.

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Re: Keith's light weight off roader

Post by KeithB » Sun Oct 21, 2018 12:31 pm

Two Steps Back

Work on fairing and sanding the sleeper is still going on. All of the bends and ins and outs on the outer surfaces of it are taking a lot of time to finish off ready for paint, especially around the aluminium half rounds which are the landings for the rubber seals. These still have to be glassed over, faired and sanded. Because the sleeper is out in the weather when it’s pulled out, wet weather had held things up a bit.
The inside is pretty well right and there are now a couple of coats of black paint on it to keep the light out. The blue stuff you can see is a bit of fairing to fix dodgy bits that only seem to reveal themselves when there’s paint on. I’ll sand them off and put some more black paint on and then a final sand before some white paint.

Image

I test fitted the side skirts for the roof and joined the longer bits with glue and glass tape while they were clamped up in situ in order to match the curve on the body. Next came scarfing of some epoxy angles at 2 inch intervals and gluing them down to the side skirts to form a curve.

Image

The holes you can see are to hold each of the segments down and to force the glue back up through the saw gaps. The screws came out as the epoxy glue started to go off. The long side skirts will need sanding off plus a bit of stiffening up with extra glass to stop them from bowing outward when they have a bit of weight on them.

The fuel lines for the water heater are in, complete with a flexible mounting for the fuel pump to keep the noise down. We may have to wrap it in some sound proofing if the noise gets a bit much.

Image

The batteries are in. I fabbed up a tray out of epoxy angle with a soft rubber lining and glued it down to the floor. It’s a close fit around the batteries. The batteries are held down with a ratchet strap as I wanted to avoid metal clamps. Turns out I had wired the battery meter shunt into the positive side instead of the earth. Yeah, I know: “read the instructions”. I changed it round and made provision for a future voltage sensitive relay to switch off at 11.8 volts (if I can get one) as a last line of defence to avoid running down the batteries, which lithiums definitely do not like.
The white box on the wall of the locker at the top right of the picture is the BMS. The hole in the wall behind the batteries if for a louvred vent.

Image

After a bit of head scratching the battery monitor is finally programmed and works fine, but the control lead I have from the console to the inverter-charger if too rigid and does not fit at the charger end, so I can’t yet charge the new batteries.

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There was, however, plenty of juice to run the fridge which, as it turns out, doesn’t get cold. I have been on to Evakoool who want me to return it to a service agent, which means pulling it right out of the camper. So I am trying to organise a house call. After the previous problem with the dud door, it’s clear that this two thousand dollar fridge was never inspected or tested before it left the factory. This fridge has been a pain in the arse and is definitely the last time I will buy a factory second.
To make matters worse, I had to raise the suspension to get access to the lower bits of the sleeper for sanding and it looks like one side now has a busted air line. How it got busted I do not know. Probably when I was wrangling all of the coolant hoses and their double clamps. Looks like the break is either under the fridge, which has to come out anyway, or inside the bathroom knee wall which is inaccessible. If that’s the case I’ll need to run a new line along the chassis and have ordered some special amour plated air line from Air Bag Man for that.

Image

I wish I had known about this stuff early enough to have used it in the first place.
But we are at last in the final stages and the big aim is to get it registered early in the New Year – even if it’s not properly fitted out.

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Re: Keith's light weight off roader

Post by KeithB » Sun Oct 21, 2018 8:10 pm

The six picture limit caught me out yet again on the last post. Here is a closer shot of some of the roof skirts with the angles cut and epoxy glued into place.

Image

Here is the profile of the front of the van. The back half out of shot is flat and level. But the roof will rise up in a curve and slope back down towards the rear to give it a bit more strength. A bit like the tip of an aeroplane wing.

Image

When it's eventually out of the garage I will be crawling around on top of it to put the solar on and we don't want it sagging. it easier to do that than go on a diet.

Keith

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Re: Keith's light weight off roader

Post by KeithB » Mon Oct 29, 2018 4:39 pm

Clamps, Clamps and more Clamps

There’s been a lot going on with this build in the last two weeks, but not a lot you can see.
The fairing and sanding on the sleeper is pretty much complete and the aluminium lands for the seals have all been faired and glassed in. We just need to sand those off, give them a bit more fairing and we’ll be ready to paint the sleeper inside and out. Then the bed can go in which will release a bit of garage space.

The fridge did not work when it was finally connected to the new LiPo4 batteries. It originally tested okay, compressor and fan running and no warning lights. So now it’s gone back to Evakool for a warranty claim because it looks like there is a refrigeration leak inside the casing somewhere.

The rest of the time has been spent fettling the side skirts for the roof to try to get them to line up and conform to the curve of the body. Because the roof and the walls meet with a little radius, I moved the side skirts in a little so that the seals would land on a more or less flat surface. This has meant a little reshaping of the skirts to fit.

Image

Image

I had to clamp all the parts in three directions to get them to sit square, plumb and in the right position for the seals. This took two trips to Bunnings to buy extra clamps, of which I already had shiploads.

Image

The joints that aren’t square have to be filled and sanded to a radius and then glassed and sanded, faired, sanded again and so on till they are ready for paint. On the other joints I used a soft epoxy putty to fill the gap. But on these I used a hard epoxy glue for a bit more strength. It looks a mess but will sand up okay ready to be glassed inside and out.

Image

The skirt at the back is a square joint which came out much neater. These still need the sanding, glassing and fairing treatment.

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As soon as these joints are finished, I’ll make saw cuts at 3 inch centres sideways across the roof panels so that they can lay to the curve and then glue them down. Not looking forward to that.

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Re: Keith's light weight off roader

Post by KeithB » Tue Oct 30, 2018 2:29 am

Apologies to anyone who looked at this post earlier for the missing pictures. Google Chrome stopped working and I tried to upload using Mozilla, which didn't work. Reinstalled Chrome and that let me fix the problem. The missing pictures are posted below.
Keith


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Re: Keith's light weight off roader

Post by Lance » Tue Oct 30, 2018 1:21 pm

Have you got an apprentice 'goffa' helping with this build Keith or is it a one man job ??
Lance & Anne
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Re: Keith's light weight off roader

Post by KeithB » Wed Oct 31, 2018 3:55 pm

Lance it's been a one man job up until a few weeks ago when a mate of my daughter's came on the payroll to help with the final stages of sanding and fairing. He is a spray painter by trade and is a dab hand with the epoxy filler. I also have a designer helping me with the drawings. We sit together with me pointing at the screen. He lays it all out and emails me the DXF files. The plastics outfit uses those files to cut the parts from sheets supplied by me on their big NC router. I have no space to cut parts at home.
Other than that I have been flying solo from the beginning. Welding, wiring, plumbing, glassing, fairing and painting have taken a fair bit out of me. I want to get it registered and insured on the road and fully commissioned and de-bugged by my 70th birthday in June next year.
Keith

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Re: Keith's light weight off roader

Post by Engel » Wed Oct 31, 2018 4:13 pm

Looks good better than I could do.
A couple of questions are you going to put windows in the sleeping area as it will get pretty stuffy in there and it will take the horse float look away from it? it is great to sleep in fresh air rather than air cond.
The mounting for the heater control should be close to the bed as we have gone to bed after warming the van up and in the early morning it is necessary to turn the heater on. The tick tick of the heater pump drives you nuts when you are camping when it is silent.
Are you concerned about the gas bottles moving and damaging the fibreglass?

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Re: Keith's light weight off roader

Post by KeithB » Wed Oct 31, 2018 5:37 pm

Thanks Engel,
We will make a decision on windows or roof hatches in the sleeper after we have had a chance to use it. I was worried about them fouling the seals. I was also undecided about maybe putting extra solar panels on the sleeper roof. But, based on my solar sums, this won't be necessary. There is a Cafrmo Sirrocco fan going in the sleeper plus an awning over the top to keep the sun off.
I take your point on the heater controls.
The gas bottles actually sit on metal and there is no contact by the gas bottles with the fibreglass.

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If they start to rub, I'll stick a rubber base in there.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Sat Nov 03, 2018 1:44 pm

Engel I forgot to mention that I've put an adjustable thermostat on the heater so that, at the moment, it comes on at 19.5 degrees and goes off at 21.5 degrees. We'll see how that works out.
The current job is mounting the now-fibreglassed skirts into position without clamps getting in the way of lowering the roof. We did a test fit this morning after removing the roller shutter and the roof slides out no problem.

So the plan is to cut the roof panels part way through at 3 inch centres so that they will lay to the curve and then glue them in. Then I'll put some supporting structure up from the inside. Those parts have were cut yesterday from 25mm low density PVC and there's some 40x1.6 aluminium square to go in underneath as well. Then we can lift the roof off and do all the finishing work at floor level. That will involve glassing, fairing and painting the outside and fitting the internal ceiling lining on the inside.

Then we turn it back over and fit the awning fixings and the solar panels. When that's all done, we wheel the van into the street and I get all of the neighbours to help me lift the roof on.
That's the plan anyway.
Keith

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Re: Keith's light weight off roader

Post by Bussy » Sat Nov 10, 2018 8:51 pm

Hi Keith,
Great to see you build progressing, it’s "almost" good to see someone else getting the skun knuckles and grey hair from the van building challenges each day.

Sorry I have not made any comments before this but have been busy dismantling my “working life” in order to retire properly. Any comments I make are for the positive and not meant to critic your design choices so hope you understand. No doubt that between all our builds and everyone’s comments, someone in the future will end up making the perfect van.

When I was looking into which way I was going to go about building my beast I was very tempted to go the composite way and damn near built a composite aircraft in lieu of a van. I felt the need for speed!

A few things worried me using this stuff in a van but obviously you are very comfortable and confident using this stuff so good on you.

One was the “R” rating of the material and most I looked at had none whatsoever and what the temperature was outside it would be damn near the same inside.
As you know the light passes through enough to be annoying, almost like a tent. Condensation would have to be managed well with good ventilation particularly in sleeping area.
The glues and epoxy used to stick it together or finish the surfaces off properly is generally toxic to water tanks and leaches into the surrounding air. Is the adhesive you have used potable? No chance of leaching into the drinking water of your tanks?
Flexing and cracking of the joints. I know some of that adhesive is very stiff and will fatigue over time. Most flexible adhesives like Sika do not adhere well to plastics and the like very well.

Three water pumps for three tanks? Would it not have saved some weight and much cost by bringing the suction lines for each separate tank to a manifold system where you could select which tank to draw from? A $10 item form a hardware/gardening store would do this job. in my experience, good quality water pumps last a long time.

You can get the one water tank gauge that shows the levels of three tanks simultaneously saving real-estate and costs for something else.
Love your choice of Victron Energy stuff, very good quality IMO.

As I said, just making comments not trying to pick it to pieces.

No doubt you have sat in it after hard days toil with a beer in hand and dreamt of where you will go in it. I used to and unfortunately each time I have been away in mine, have not just sat there and said, well here I am, and savored the moment. Must remember to do exactly that next time.

Enjoy the challenges bloke and keep up the excellent work as it will be worth it in the end. I know.

Cheers - Allan
Computer Engineer. 200Series TTD Altitude SE with TAJ in tow.
Home built 21.6ft off-roader "The Taj Mah AL".
Steel Chassis, Simplicity Suspension, Aluminium Frame.
Paulownia Cabinetry, 800 W solar.
Its finished, now WE retire.

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Re: Keith's light weight off roader

Post by KeithB » Sun Nov 11, 2018 11:12 am

Thanks Allan.

Love your build! I went with composite for its light weight and high impact resistance. A huge amount of effort has gone into ensuring the integrity of the joints. I have used 40mm x 2mm epoxy bonding angles inside of joints that won't be seen. On the outside, the exposed edge is routed out, filled with epoxy, radiused and then double taped before fairing. Internal joints that are seen are filleted with epoxy prior to glassing. I have gone for epoxies throughout because they are much stronger than other resins and don't stink the place out and have used woven glass rather than chopped mat.

Early in the piece I joined two pieces of scrap composite to form a tee using fillets and glass tape on both sides of the tee. I clamped it to a post and put a jack under it. The panel deflected by about 30 degrees without the joint failing. This material is used extensively in boat building, so we'll see how it fares. Epirez makes an epoxy that is certificated for potable water. The tanks are lined with that and it should keep the light out as well.

I think you are right about there being no R rating on this or any composite material and I have had to put five coats of black paint under the white to keep the light out. I didn't like any of the foam core composites and balsa core was too expensive. There is actually very little wall exposed from inside of the main body due to lockers, cupboards and things. The floor is nearly all water tanks. The roof will be covered with nine thin wall solar panels with an air gap underneath to form a bit of a tropical roof and the ceiling will be lined and insulated. The plan is to have a little roll out awning to keep sun and rain off the sleeper for longer stays. The bed base has a 30mm air gap under it. Given that a lot of the wall space is canvas (or vinyl) I wasn't too worried about the R rating. I take your point on ventilation.

I see a lot of vans with storage lockers everywhere for stuff and not enough room for people. By maximising people space, my big challenge with this build is finding enough space for all the equipment. As you can see, the smaller things are located behind the kitchen kick boards and on the back wall behind the drawers. I thought that using a bunch of valves to select a water tank was a bit fiddly. I would be carrying a spare pump anyway, so one extra is no big burden and the ability to select a tank with a flick of a switch is very convenient. The three gauges are so that I can move water around if weight distribution is a problem. But I agree that three gauges is unnecessary.

I suppose that there are a whole lot of things that I would change if I did another build. But I guess every builder has the same thoughts. I would make the bathroom 100mm wider and allow a bit more room for the fridge. I also should have used better runner for the slide-out bed. If it comes in at under 1,500kg dry I will be very happy. That's very light for a van with almost 19ft internal length. Let's hope it hangs together.

Keith

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Re: Keith's light weight off roader

Post by KeithB » Thu Nov 15, 2018 2:36 pm

It's Roof Time

After hours and hours of sanding, the slide-out bed is now pretty much painted. But the paint went on a little dry and will need a light sand with wet & dry on the outside. The interior will need a fourth coat of white to cover the four coats of black that keep the light out.

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We have made a start on the outer skin of the roof, which is in two pieces and follows a curve front to back. So we have made cuts at 50mm or 100mm centres so that the roof panels could fall naturally to the curve. The tighter the curve, the closer the cuts. Here is the rear roof skin ready to go on. The curved corners are for an overhang of about 125mm at the back so that rain water can fall of the caravan without running down the back wall where the seals are.

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The front section of the roof is epoxied in place and I just need to router it out at the edges so that they can be filled with epoxy putty and routed and sanded to a radius ready for glassing.

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I had to put a large amount of epoxy glue onto the top of the roof skirt to allow for a 1-2mm glue joint. A whole lot squeezed out, which I couldn’t get at, which means we will have to remove the roof to sand out the excess plus reinforce the joint with some extra glassing. Here’s the joint from inside.

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I have had some 25mm low density PVC material machined up to match the interior curve of the roof. These and some bits of 40 x1.6 aluminium square will brace it and provide and anchorage for the ceiling lining with a 40mm air gap.

So the plan is to get the roof skin bonded to the skirts and then fill all of the cuts with epoxy. We then remove the roof to clean up and reinforce some joints from the inside. Then it goes back onto the van so that the roof scantlings can be positioned accurately with respect to the walls, to ensure that the canvas will fit evenly. Then the roof will come off again to be finished, wired, lined and solar and dust suppression fitted. We’ll also fit the brackets for the awning, which will go on last of all because it weighs about 27Kg.

When that’s done, the roof will be too difficult to lift back on while the van is in the garage. So, we’ll get all of the neighbours to help with a big lift when the van is on the street early next year.

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Re: Keith's light weight off roader

Post by KeithB » Sat Nov 24, 2018 9:39 am

The missing lead for the inverter charger finally arrived and I have been able to get a bit of juice into the batteries. But the 70 amp charger ran at only 48 amps and less than 14 volts, which took about five hours to bring the batteries up to float. It’s supposed to charge at 14.4 volts so I’ll have to look into the dip switch settings.

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The cool thing about the control panel for the inverter charger is that you can select how many amps you want to draw from the mains. Here it is set on 15 amps. But you can dial it down if you are running from a small generator or a dodgy mains source. If the demand inside the caravan exceeds the limit set on the panel, it draws the excess from the batteries and then goes back to charge again when the demand drops.

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The fridge came back from the Evakool repair agent who seems to think that it left the factory with no gas in it. So go figure. We’ll run it flat out for a month or so before properly installing it to see how it goes.

The roof is coming along quite well. We have it all glued down. Next step was to router it flush with the skirts, then router a groove for the filler, bung the filler in, sand it off flush and the router a radius in the top edge ready for glassing. Here’s a shot of the filler with the sanding just starting and another shot of the thing wrapped in plastic while I glassed it all with two inch tape.

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The glassing was yesterday and today we slid the roof off out the back and layed it upside down on some benches. Then we ground off all the glue dags, stuffed filler into various holes and layed down some fairing in preparation for some reinforcing glassing with 6 inch tape in the next few days.

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Re: Keith's light weight off roader

Post by KeithB » Sun Dec 09, 2018 5:35 pm

Some roof work after the flood.

Progress has been slow over the last few weeks. During the last Sydney storm, we were in the middle of a box gutter repair on our house. I had rigged some tarps which worked well in what rain came along. But my tarp arrangement couldn’t cope with 90mm in 90 minutes and the ground floor of our house, where the bedrooms are, got a bit of a flood. I was on my own as the rest of the family was away and spent days dragging furniture, pulling up carpet, and running big blowers and dehumidiefiers for a week 24/7. But we’re almost back to normal now.

In between domestic flood duties I have been trying to commission the diesel heating system. It’s all primed with coolant, diesel tanks full and the wiring in place. Here’s a shot of an external DB board I rigged up to keep all of the wiring out of the plant locker at the front.

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I originally had trouble wiring a flash illuminated ON/OFF switch on the interior panel but eventually got that sorted after some advice from friends. Thanks again guys. But I couldn’t get the thing to fire up. There is power across the fuses in the little box on the bottom right corner of the BD board, but no power to the switch. So it’s either a faulty loom (which I had shortened up by a marine sparky) or a fault in the heater. So I have emailed Diesel Heat for some help. Maybe try it with a stock loom.
With Sean’s help, the side skirts of the roof are all now faired and glassed internally with 6 inch tape. Here’s a shot of where we are at.

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I had some curved rails N-C routed from one inch thick low density PVC plus some others from half inch. They are epoxy glued into place before glueing in 40x1.6 aluminium RHS crossways at mostly 610mm centres. The holes you can see down the left hand side are for wiring. Here’s a close up of how the aluminium is epoxied onto the side rails using pieces of epoxy angle.

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There are three more 45X25 curved beams machined up but I don't think I will need them.

I’ll need to fit some framing into the roof for the hatch which needs a 400x400mm hole. I won’t do that till the hatch arrives. A layer of Gunnersons RV lined plywood 3.2mm thick will sit between the side rails glued and screwed up to the structure you can see.
At the front of the roof, we have the bathroom area which will not have a ceiling lining due to restricted headroom. Like the rest of it, there is a lot of fairing and glassing still to do. But the bathroom roof will need extra attention as all of the joints will be seen. Here’s what it looks like waiting for fairing and paint.

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Still plenty to do.
Keith

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Re: Keith's light weight off roader

Post by Archer63 » Sun Dec 09, 2018 6:47 pm

An update at last Keith...was starting to wonder if you’d dropped off the perch or something 😳
I suppose the recent Sydney rain dump was a fair excuse for lack of updates, but hopefully not a regular occurrence 😁
Jokes aside...glad to hear everything is ok and your back on track...apart from the hit to the hip pocket of course 🤬
Cheers
Rob
2018 Pajero Exceed
2013 Jayco Swan Outback

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Re: Keith's light weight off roader

Post by KeithB » Sun Dec 09, 2018 6:59 pm

Thanks Archer.
I am supposed to be retired from the business I sold. But they keep calling me in for emergency directors meetings. By the time I change out of my work pants, get dressed, motor into the office, do the blah blah, come home and change into my old pants again: that's a morning gone.
It's only been three weeks since my last post. But if I posted daily it would be pictures of me sopping up water and changing my pants.
Nobody needs to see that.
Just to update:
I have taken delivery of 990 watts of thin film solar panels from Solar 4 RVs and a 3.5 metre Thule electric awning with anti-flap kit (whatever that is) plus a big box of stainless steel button head bolts. So the bank balance is in worse nick than the carpet.
Keith

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Re: Keith's light weight off roader

Post by brett&kat » Mon Dec 17, 2018 3:50 pm

What brand of thin film solar did you get of solar 4 rvs?? I was looking at the eArche panels but still need to ring them and do more home work.. Great build, interesting watching you build with composite material.

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Re: Keith's light weight off roader

Post by KeithB » Tue Dec 18, 2018 11:10 am

Brett, I went with the RAD Power-Sunpower GenIII panels because of their lighter weight. But they are not easy to fit. There is a prescribed procedure which means using a special double sided tape to stick on strips of thin wall polycarbonate roofing between the cells to provide and air gap as well as special safety clips in case the adhesive fails. Solar 4 RVs supplied the tape and the polycarbonate strips.
The upside for me is that the solar panels will form something of a tropical roof.
I am not at the stage of installing them yet. Still trying to get the roof finished.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Fri Jan 04, 2019 6:33 pm

When stuff that supposed to work doesn’t.

Had a bit of a break over the Christmas period but still managed to get a little bit done. But first we had to take two steps back.

While the non-working fridge was out being looked at I had a poke around and found the leaking air line under the fridge cabinet, which was an easy fix. The repaired fridge came back from Evakool mid November but I didn’t connect it up until several weeks later when I had the LiPo4 batteries installed and charging properly. The fridge part worked fine but the freezer didn’t work. Several days later neither of them worked. I emailed Evakool on Christmas Eve and they told me to send it back. I’ll do that next week when everyone’s back at work.

Getting the fridge out involves moving just about everything in the garage, getting a mate to help me out with it, hiring a trailer and then making a two hour round trip to the service agent. First time I expected a replacement fridge and tore the Sikaflexed surround off, requiring a replacement set to be made up. I had originally asked the service agent to run the fridge flat out for two weeks before I picked it up and he swears that’s what’s happened. Looks like a very slow leak inside the cabinet. It's evident that the fridge had been recharged prior to original delivery. I am going to ask Evakool for a new fridge and will happily pay the difference between the new and factory second price. I think I got a factory third.

Meanwhile I received a stock loom from Diesel Heat and tried that out after the heater failed to fire on the loom that I had had shortened by my marine sparky. It fired up a treat a few times and then refused to start. Diesel Heat suggested I clamp the coolant lines, pull the furnace off the heater (one bolt) and send it down to them in Tassie overnight. I caught the late post on the Tuesday and it was back with me on the Thursday morning. Apparently it was a crook glow plug. It’s miles out of warranty but Diesel Heat refused to charge me. They are great people to deal with.

The diesel furnace is working a treat now with the replacement loom and the heated towel rail is toasty. But I can’t get any coolant through the fan heater. It looks like either a kinked hose (I hope not) or an air lock that is refusing to budge. So I bought a little 12 volt 8l/min solar recirculator pump on eBay. I’ll plumb that in and see if I can get a result.

Meanwhile the roof has been coming along. I figured out where the solar panels will go, selected a location for a 400x400 Sietz hatch and framed up for same. The frame is epoxied down and glassed around the outside perimeter. I’ll router out the hole when the roof is glassed from the top.

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The roof has a whole load of cuts in it to form the curve – at 100mm centres mostly and at 50mm centres at the front where the curve is sharper. How to fill the cuts, which extend deep through the plastic honeycomb core? I liked the suggestion to use expanding foam. But I was worried that it might not be compatible with the epoxies I am using, which can be a bit fussy. I had previously purchased a crate of empty caulking cartridges which you fill from the back, push in a plastic cap, snip off the nozzle and use in a conventional gun. I used these with epoxy resin thinned to 10-20% with acetone. To refill, you just blow the cap out with compressed air and reuse. I did one fill this way and got nowhere. The honeycomb just swallowed the resin after the original fill. I decided then to pour the thinned resin on and then squeegee it about and sand off.
Here’s what it looked like with the resin squeegeed on:

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Here’s Sean doing some of the sanding:

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This left a 5mm deep slot which I filled using the cartidges.
The entire fill took about 4 litres of resin and still left a little gap at the top due to the surface tension in the resin. So, without sanding I went over the gaps with fairing compound ready for sanding. Here’s what it looked like after that:

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The plan for tomorrow is to sand it off. Level the roof up to that there are no twists in it and lay down two lengths of 1 metre wide glass cloth. Sounds like fun.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Sat Jan 05, 2019 2:16 pm

It’s been 36 degrees in the shade in Sydney this morning, which we basket weavers aren’t used to. So we called a halt to work at lunch time. But we did get the top of the roof sanded down and a layer of 1 metre wide cloth laid up on one side. Here’s what it looks like:

https://gdurl.com/zy8M

It’s a two man job to get the cloth down on top of the epoxy resin and the bubbles squeezed out, with one of us perched on the roof. So we can’t do the second half until the other side has gone off. That was a good enough excuse to down tools, get a cold drink and tune in to the cricket.

We used 10 inch cotton rollers this time rather than brushes and they worked a treat, giving a far better finish than I could ever get dabbing with a brush. This one side took about 700mls of resin. Will do the other side tomorrow. Then we can (a) start the fairing and (b) start figuring out the dust suppression cowl.

Back to the cricket.
Keith

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Re: Keith's light weight off roader

Post by Old Techo » Sat Jan 05, 2019 7:36 pm

I've had nothing to say but I have been following this very interesting topic and great pics :D
Regards, Old Techo
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2004 Roadstar Limited Edition

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Re: Keith's light weight off roader

Post by KeithB » Sun Jan 06, 2019 11:11 am

Thanks Old Techo. We just got the other half of the rooftop glassed. This morning is about 20 degrees and yesterday was 38. The cooler temperature makes the resin thicker and harder to spread or penetrate the cloth. In fact on cold days you have to thin it with 10% acetone, which I don't like doing. As a result we used 50% more resin today than yesterday. Now to put some extra glass onto the the side skirts to stiffen them up plus a drip edge on the awning side to direct water to the front and rear. Then we can start the fairing.
Thanks for your interest.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Sun Jan 13, 2019 3:22 pm

Painful Progress

Fan heater tale of woe.

I mentioned in an earlier post that I was having trouble getting the hot coolant to go through the heater back in the body of the van. It turned out that there were three problems: (1) the pump in the heater furnace is not man enough; (2) there was a mystery set of plugs in the fan heater; and (3) me.

I blew out the supply hose to the fan heater and incorrectly concluded that it was blocked, probably by a kink. That surprised me because I had taken great care when I laid them out before glassing in the bulkheads. It turns out that I had had a major brain fart and got my inlet and outlet hoses mixed up. I did not realise that at the time, so I cut the (incorrect) offending hoses off to gain a bit of space and ran a replacement supply hose down the chassis, something that I had sworn not to do.

Suspecting that the pump in the furnace might be a bit light-on for two heating appliances, I bought this little hot water recirculator pump on eBay and plumbed it into the supply line downstream of the furnace. It’s 12 Volt. 0.7 amps, 8litres/min and a max head of 3 metres. I put it in also as a temporary measure to push any air through the system.

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But still no luck, so I called Graeme at Diesel Heat. Turns out that there are caps on the heater tails which are not mentioned in the instructions and don’t look to me like caps at all. They have what looks like a hole down the middle and look like part of the fitting. You can’t pull them out by hand or with slight force using pliers. Here’s what the heater looks like with the caps in.

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So I pulled and pulled and got the first one out. But the second one came out complete with the copper tail. So I ordered a new fan heater and put it down to experience. I’m getting rather more “experience” than I need lately.

Having removed the plugs and plumbed in the little recirculator pump, I topped up the coolant, opened the supply valves, turned the furnace on and guess what? Fourteen litres of coolant came out of the cut hose inside the cabin in double quick time and left me with a shiny flouro-green dance floor. An hour of wet-dry vacuuming and a lot of dirty towels later I reconnected the cut hoses using double clamper joiner and got them right this time. Now we had hot coolant going through both the towel rail and the fan heater. Hallelujah!

Wondering whether the little pump was still required, I took it out of the circuit, only to find that the fan heater took ages see any coolant and was barely luke warm. So I called it a day. So the next step is to plumb the pump into the fan heater circuit so that it only runs when the fan heater is on. I’ll check its suction lift while primed with water before I do that to make sure is doesn’t cavitate.

The Fridge Saga.

At no charge, Evakool has agreed to supply a brand new fridge to replace the faulty factory second one that I bought and it looks like it will arrive mid week. Then I have to reuse the packaging to box up the old one and they will have it picked up. Well done and thank you Evakool. I have ordered a new stainless steel surround from the local sheet metal shop as I destroyed the old one getting it off the fridge. Jeez that Sikaflex can stick. I had to drag it off the fridge using a come along.

The roof.

We got the other side of the roof glassed, it’s now all faired in preparation for sanding and two coats of black paint to keep the light out. Here’s what it looks like before we get cracking on the final sanding this week.

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I have started laying out the dust suppression blowers that you can see in the foreground. They will blow into the bathroom via two 90mm PVC bends. They will have a cowl over then with a solar panel on top of the cowl. Here’s a close up of the blowers.

Image

Just behind the pots of fairing compound you can just see the cut out for the roof ventilation hatch, which was framed up earlier. I took a lot of time to drizzle resin into the cuts that we put in to get the curve. When I inspected the cutout piece, it was good to see that the resin has soaked right though and filled the honeycomb completely. A win!

I have a gasfitter coming tomorrow to see if he can rerun all of my gas pipes to meet regulations and sign off on a certificate. I’ll clean up the garage and put the roof back onto the caravan so that he has room to work. Then it’s the final fix on the heating system and a whole load of prep and painting on the roof.

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Re: Keith's light weight off roader

Post by KeithB » Tue Jan 15, 2019 5:17 pm

We have heat!

I got all of the piping and wiring squared away in the little locker near the door and connected the thermostat and manual over ride. Here’s what it looks like:

Image

The thermostat shows the temperature when it’s in either automatic or manual mode and turns the fan heater on at 19.5 degrees and off at 21.5 degrees, which can be adjusted. The thermocouple is Sikaflexed onto the bottom louvre of the black plastic vent you can see there. This provides cold inlet air. The pull knob to the right of the thermostat is for OFF - AUTO – ON. The little circulator pump inside the locker comes on in either AUTO or ON mode.

Image

Here’s what it looks like from the fan heater side. The heater has a switch at the bottom that selects the fan speed. I tested it running flat out using and ice pack to make sure that the temperature controller is doing its thing, which it is. With the heater furnace, the fan heater and the circulator pump all running flat out and the towel rail toasty, the whole thing draws 3.2 amps, which I am happy with.

I pulled the shortened wiring loom out this morning and took it back to the marine sparky to be fixed. After that I’ll send the new replacement back to the factory. It’s a small victory I know. But after all the balls ups with this heating system, I need one.

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Re: Keith's light weight off roader

Post by KeithB » Sun Jan 20, 2019 2:55 pm

More on the roof.

It was a bit too hot for us southerners to work this week, but we did make some progress. We got the final sanding done plus a coat of black paint on the roof yesterday morning. In the afternoon my engineering design friend Anish came over to resolve the dust cowl. He is a genius on Solidworks and a stickler for detail. Here’s what the roof looks like with four of the nine 110 watt solar panels roughly positioned and still in their bubble wrap.

Image

Here you can see that the front solar panel occupies the same real estate as the dust suppression fans and filters.

Image

This means that the cowl that goes over the fans and filters will need to be big enough to house the centre panel. Here’s what Anish came up with.

Image

The pipe cut-ins into the roof are not shown. The idea is that the cowl will be hinged at the back and will lift on a couple of gas struts for maintenance access. The grey thing at the front is a 50mm thick commercial honeycomb range hood filter that a local outfit will make up to suit. These make really good dust filters when they have a bit of oil on them. On the front of that will be a bit of flyscreen to keep insects out. I hope is doesn’t look quite as ugly in real life as it does on the drawing.
I’ll take the DXF files out tomorrow to get the parts cut.

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Re: Keith's light weight off roader

Post by KeithB » Wed Jan 30, 2019 4:08 pm

Cowl progressing slowly

Not a lot of progress during the last week as I wasn’t happy fiddling with epoxies on those few really hot days because of the reduced pot life. We got two more coats of black onto the roof, which will need a light sand before four coats of white.

The cowl parts came back all N-C routered to the correct curves and the lower edges match the curve on the roof exactly. Making the cowl is much the same as making the roof, except that the cuts are on the inside. The cuts on the roof are on the outside to keep the ceiling in the bathroom, which is not lined, looking as good as possible.

First thing was to router out the edges, fill them with epoxy and sand them off smooth. Then came cuts into some pieces of 40mm epoxy angle so that they would bend to the curve and support the roof of the cowl. They were epoxied onto the sides of the cowl and temporarily held with screws till the glue went off. Then the roof of the cowl was sliced almost through at 2 inch centres on the underside to allow it to fall to the curve made by the angles glued onto the sides of the cowl. I am using the roof of the caravan as a temporary bench as there is no other space in the garage. Here’s what it looked like roughed in.

Image

The top was screwed down to compress the glue joint and squeeze out any excess glue which comes off later with the sander. Squeezing out the epoxy glue gives an extremely strong joint.

Image

Here’s what it looks like with the rear one inch thick PVC panel to mount the hinges rouged in with a bit of fairing over the cuts, dings, gaps and screw holes. This will sand dead smooth with a bit of 80 grit ready for glassing.

Image

This was then sanded off and glassed over. The outer edges were all radiussed with the sander and glassed over as well. So has the underside. You can't see it properly in this photo, but all of the visible pink edges and the curved joints with blue fairing on them have been glassed over and the edges of the glass cloth feathered with the sander.

Image

The on went the first stage of the final bit of fairing. I’ll do the rest in the morning before the weather warms up. Then it’s more sanding ready for paint. I won't finesse too much on the underside as it won't normally be seen. But the cowl will stand out like dog's balls and will need to look as good as I can make it.

Image

The replacement fridge arrived this week, but the local sheet metal shop got the dimensions of the mounting strip all wrong and had to make another one. It has to be Sikaflexed onto the side of the fridge using the wide surface you can see here. Stainless steel screws go in from the other side. That’s the next job. Or one of them.

Image

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Re: Keith's light weight off roader

Post by Collyn » Thu Jan 31, 2019 8:11 am

Keith

Great job, particularly workmanship!

One comment.

Would you consider relocating those two spare wheels? Right now they are at the worst possible location for stability, as they hugely increase yaw inertia where you need it least. This is not good even on a heavy trailer - but it introduces seriously unnecessary issues for an ultra-light one. You seem to have ample space for at least one - under the 'van.

Also, why two spare wheels - particularly if you were to use the same as the tow vehicle? My wife and I crossed Oz (from our then home in Broome to Sydney and back over 12 times (i.e. plus 24 return trips each of over 11,000 km) with our OKA and later Nissan 4.2 litre Patrol and TVan - and only once needed a wheel change in that total of plus 250,000 km.

Am just completing an all-new (digital) book in just this area - could send you a freebie copy as it is right now - as that explains all in both lay and technical terms.

(I have a life-long background in this area - as an ex test engineer at Vauxhall Motors Chaul End Research Lab.)

Collyn
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Re: Keith's light weight off roader

Post by KeithB » Thu Jan 31, 2019 9:13 am

Thanks Collyn.

I'd love to receive a copy of your new digital book. Thanks for the offer. I'll email you in case you've lost my address.

I take your point on the location of the spares. So much so that I have already ditched one of them and ground off the bracket. The 30kg mag wheel spare ended up being a 40kg spare after I put a 285 33 inch tyre on it to match the tow, which has two spares anyway. I have opted for one spare per axle for remote travel, which may be a bit of overkill. But I did destroy two rear tyres going over the Simpson, the result of a manufacturing fault by Mr Cooper.

The entire underside of the caravan is water tanks and there is not a square inch of spare space andwhere. But there's a gauge and a pump for each of the three fresh water tanks so that I can manage weight distribution. The unfortunately sideways picture below shows the tanks with the whole arrangement face up instead of face down. The tanks are load bearing and the chassis is shown in outline.

Image

The centre of gravity will be quite low and the roll centre quite high, but I do agree with you that the weight down the back is a significant flaw in the design. To make matters worse, there is a 29kg aircon going on the back wall as well. I have tried to counteract that by locating the axle further back than on most caravans, not unlike a boat trailer. In fact the centre of the spare is just 1600mm away from the axle and the aircon about 1500.

I'll see how it tows and maybe extend the drawbar and mount the spare on that as Bruder has done. Thanks again Collyn.

Keith

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Re: Keith's light weight off roader

Post by Collyn » Thu Jan 31, 2019 11:12 am

Keith

As you are probably aware rear end mass is far less an issue with short trailers (as square laws are involved).

The vital thing is that the tow vehicle can never at any time be caused to over-steer. Except in extreme cases, this be done by ensuring tow vehicle front/rear tyre pressures have the essential ratio difference.

Collyn
Last edited by nimdA on Fri Feb 01, 2019 7:35 am, edited 1 time in total.
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Re: Keith's light weight off roader

Post by Bussy » Fri Feb 01, 2019 9:47 pm

Hi Keith,

Keep up the good work and great to see your van is still progressing.
I have only 1 x 4" Rule bilge pump pushing air into mine and I think that is enough. What lets me down it where the air pressure escapes from, roof vents which have gas ventilation compliance holes etc. and rear fridge vents, you know what I am talking about. Its not really the air in it the air out.

Also are those fans serviceable in your cowl? can you get at them/remove them to fix as I know some brands of fans are only for intermittent use so sounds like they could wear out quickly if run for a long time on slow dusty runs out bush.

Yes its always a good idea to label all wires and pipes each end as it might be weeks or even months before you get back to the build or that particular part of the build and you then have to guess what you planned / did ages ago. I used simple sticky tape and written labels before buy a label machine. I then heat shrank clear tube over the labels for future proofing as best as possible.

Cheers - Allan
Computer Engineer. 200Series TTD Altitude SE with TAJ in tow.
Home built 21.6ft off-roader "The Taj Mah AL".
Steel Chassis, Simplicity Suspension, Aluminium Frame.
Paulownia Cabinetry, 800 W solar.
Its finished, now WE retire.

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Re: Keith's light weight off roader

Post by KeithB » Sun Feb 03, 2019 7:03 am

Thanks Allan.

That build of yours is legendary!

The cowl will be hinged at the back and will lift with a couple of gas struts. I haven't figured out yet how to attach the hinges and hold down clamps. Like you I was sceptical about how long these blowers would last. But a couple of other guys have reported using them for years without any failures.

Holes everywhere do make it hard to pressurise the van and a little computer fan continuously ventilating my composting loo makes things even worse. I oped for two fans because they lose a lot of flow due to the filters, which were the biggest I could fit.

I noticed that you have done your joinery out of Paulownia. A mate of mine is making my drawers out of the same stuff. I found on some test pieces that the grain tends to be a bit fury when you try to sand and paint it. How did you manage to get such a good finish?

Keith

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Re: Keith's light weight off roader

Post by Collyn » Sun Feb 03, 2019 7:19 am

Another extraordinary ultralight build is a campervan with pop top roof, a slide out and a toilet all built on a new Nissan 4WD chassis by Dick Clark (Envirotec). The entire structure (over and above the chassis) is only 375 kg, Uses seriously hi-tech material including carbon fibre. I will be writing it up and publishing later this year. Also with Glenn Portch's 11 metre 5th wheeler - that is 3200 kg with 1500 kg payload.

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Re: Keith's light weight off roader

Post by KeithB » Sun Feb 03, 2019 9:48 am

Collyn,
I think my structure, including 1500mm slideout is just under 400kg. Then you start adding proprietary products like fridge (57kg), batteries the same, BBQ (27kg) and water heater (25kg) and all your painful weight saving in the structure disappears. I would love to have used a more exotic material but the extra expense, workability and marginal weight gain didn't seem to make sense.
But I love this cutting edge stuff with exotic materials and wonder when it will start to become mainstream. We are seeing a lot more use of composites in caravans these days, which is really good.
Keith

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Re: Keith's light weight off roader

Post by Bussy » Sun Feb 03, 2019 8:49 pm

G’Day Keith, yes a few people have found it hard to get a nice smooth finish and commented the same re the paulownia.

I did not think it was all that bad. Just a good sand then dust off with compressed air then sprayed with Dulux undercoat. Allow plenty of time to dry then sand again and dust off before another spray of undercoat. Final finish was two coats of aqua enamel gloss sprayed on. Note they were only sanded after second undercoat and NOT sanded between final coats of aqua enamel gloss.

Cheers - Allan
Computer Engineer. 200Series TTD Altitude SE with TAJ in tow.
Home built 21.6ft off-roader "The Taj Mah AL".
Steel Chassis, Simplicity Suspension, Aluminium Frame.
Paulownia Cabinetry, 800 W solar.
Its finished, now WE retire.

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Re: Keith's light weight off roader

Post by jailbar joe » Sun Feb 03, 2019 10:38 pm

enjoying your build keith it is just sooooo different to my build ...i can only imagine the frustration/excitement that is going into it
looking good
cheers
joe


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Re: Keith's light weight off roader

Post by Collyn » Tue Feb 05, 2019 8:08 am

KeithB wrote:
Sun Feb 03, 2019 9:48 am
Collyn,
I think my structure, including 1500mm slideout is just under 400kg. Then you start adding proprietary products like fridge (57kg), batteries the same, BBQ (27kg) and water heater (25kg) and all your painful weight saving in the structure disappears. I would love to have used a more exotic material but the extra expense, workability and marginal weight gain didn't seem to make sense.
But I love this cutting edge stuff with exotic materials and wonder when it will start to become mainstream. We are seeing a lot more use of composites in caravans these days, which is really good.
Keith
Keith

There is now a very strong case for using LiFePO4 in RVs where weight is at a premium. They are one third the weight and volume for the same nominal capacity - but as one can safely and routinely use 70% of their capacity - that 100 Ah LiFePO4 is the equivalent of at least a 130 Ah AGM. You can thus see them as 25% the weight and volume.

Further, they maintain 13.1-12.9 volts (almost regardless of load) down to 20% remaining - and even a 100 Ah one can be charged (and discharged) safely at 300 amps! T They need a dedicated battery management system and a charger with LiFePO4 programme - but many are now available.

But were I re-building a coach I'd use about 350 Ah of AGMs.

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Re: Keith's light weight off roader

Post by KeithB » Tue Feb 05, 2019 4:10 pm

Here's an interesting take on LiPo4 batteries:
https://www.exploroz.com/Members/140130 ... rsion.aspx

It has yet to be demonstrated because these batteries have not been in caravan service for long enough. But I won't be at all surprised if, over the life of a well cared for lithium battery setup, the cost of ownership will be equal to or less than AGMs. The weight and space savings and the other electrical advantages are a plus as well.

Keith

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Re: Keith's light weight off roader

Post by KeithB » Fri Feb 08, 2019 4:36 pm

More roof work

We sanded down the black paint on the roof with 220 grit and got three coats of white paint on. You can lay it on thicker on a horizontal surface and I think the three coats will do it.

Also painted the outside of the cowl, fitted some big stainless steel hinges at the back and some epoxy angle brackets and screw-down bolts at the front. The bolts are secured with stainless steel tee nuts and don’t have to be super waterproof because they are outside of the canvas. I have some gas struts but haven’t decided whether to fit them or not. I am waiting for the fish shop filter for the front of the cowl, which is about ten days away and will paint the inside of the cowl and fit some seals to the base after they are in.

I cut and glassed two bits of 90mm PVC pipe into the roof of the bathroom to take the dust fans.

Image

Image

Image

After much huffing and puffing we got the replacement fridge in. It’s a tight fit and it looks like half a millimetre here and there were the cause of all the problems. But nothing that couldn’t be solved with brute force and ignorance. I’ll get it running tomorrow and make sure it works properly before the final fix.

I got some friends to help and we lifted the roof out into the street, turned it over and put it back inside ready for internal paint and fitting the seals. I have had some lengths of 12x3 aluminium drilled and countersunk at 50mm centres to hold the seals in. There’s no space to do that in my crowded garage. We’ll get started on that as soon as the internal painting is done.

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Re: Keith's light weight off roader

Post by Collyn » Sat Feb 09, 2019 10:35 am

Keith

When first writing about LiFePO4 about six years ago, I copped at a lot of flack when I advised caution as (very few people - apart from Terry T1) truly knew about them back then. One almost needed to join a sort of lithium priesthood to find out.

We do still have a situation where many battery vendors still do not stock them - but it can (I feel) be taken for granted that, if used as intended they are truly worth their price. Whilst they are three or so times the price of AGMs (unless you know enough to assemble individual cells) they cannot be compared on an amp hour basis. Watt hour is closer but as a rough guide a 100 Ah LiFePO4 (in RV use) is at least the equivalent of a 150 Ah AGM.

If weight and volume is no issue however, anything over 300 Ah of AGM's will provide all the energy and power you will need in a typical RV.

(Am just about to install a 5 kVA of LiFePO4 to my now 6.5 kW solar array for our home).

Collyn
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Re: Keith's light weight off roader

Post by J.REEVES » Sat Feb 09, 2019 11:31 am

Almost four and a half years with lithium now and shows no sign of any issues.

Had plenty of advice on Terry T1 forum but don’t know what all the fuss was about as I have done nothing like cell balance and all that stuff, just use it.

It is handy to have a bit of tech knowledge as this will save you lots of money on a BMS. I personally spent $50 to $60 on a BMS which works for me.

My 200AH lithium (4 cells) cost about $1250 so for about $1350 you can have 200amps flowing from the battery and still have 13volts on the battery that’s what impresses me.

JR
:razz:

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Re: Keith's light weight off roader

Post by KeithB » Sat Mar 16, 2019 8:07 pm

Gas Fitting.

I have been having a lot of trouble with the slides and it's all my fault. I masked them up to do some fibreglassing and painting above and forgot to remove the masking take before pushing the slides in. Now I have to pull them out to clean or replace them. If I have to do that I'Il have to look at what improvements can be made.

Apart from my woes with the slides there has been some progress in the last five weeks. But I have been hampered by wrist injuries. I have metal plates in both wrists and sometimes they play up so much I can hardly even pick up a cup of coffee without a lot of pain. But we press on.

I think I mentioned how I made a real mess of the gas fitting. Workmanship wise, it’s great. But I built it to the wrong code. It seems that caravans are different to boats when it comes to gas lines. So I got a gas fitter in, who did the work and gave me a plate and a certificate. Trouble was, I wasn’t happy with the job.

Image

I arranged for the gas lines to be enclosed in thick-walled automotive heater hose, which provides fantastic protection for the pipes. But they still have to be kept out of the way of rocks. The picture above shows the original installation with the gas pipe coming over the wheel arch, well inboard of the wheel and out of the way of rocks, then coming down to the underside of the floor the up to the BBQ, which you can see on the next picture. Trouble is that the BBQ is behind the bulkhead to the right of the picture and the gas line should have gone in through there. But here’s what we got:

Image

It comes out from the wheel arch, several feet back down the chassis and then up via a valve through the floor to the BBQ . Problem is that all of this gubbins is right behind the wheel. I spewed when I saw it but the gasfitter said it was to Australian Standard and that was that. It has been screwed into the 1mm skin on the composite which would have a life expectancy of about half an hour on a dirt road. So a heated discussion ensued after which it was agreed that I’d fix the mess and he’d come back to inspect and test. So I re-ran the pipe like this:

Image

I used a plastic bulkhead fitting in the wheel arch but I will make glands for the rest of the hose penetrations with either solicone or sikaflex.
And onward into the BBQ like this.

Image

Then another problem arose. I talk a lot about problems don’t I? The gas fitter advised by phone that the diesel heater exhaust was too close to the outlets of the gas cylinders. Here’s what it looks like and sorry it's sideways:

Image

The distance measured at 830mm when it’s supposed to be 1500mm. I checked with the manufacturer and the diesel furnace has no flameproof rating and I doubt that a spark arrestor would be acceptable, even if I could find one. So I have ordered a long length of the stainless steel exhaust pipe so that I can take it down through the locker and back and out the starboard side below the floor. There is a 2 metre limit on the exhaust run.

There’s lots more to report but I’ll save that for when I have a bit more energy.

Keith

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Re: Keith's light weight off roader

Post by jailbar joe » Sun Mar 17, 2019 12:26 pm

sorry to hear of your pain keith...seems we are all destined to work in pain these days :roll:
hate to say it but your problem has come at a good time for me :o as i sit on my bum sooking i am thinking about my gas
hook up.

to this point other than situating my stove and h/w service i have done nothing other than thinking about it.....
very shortly i will be engaging a plumber mate to do the gas hook up for me and you have given me some parameters to work
to and reinforced some of my ideas so on that note i thank you.

everytime i get stuck yours and bussy's thread are my main source of reference again thank you
cheers
joe


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Re: Keith's light weight off roader

Post by KeithB » Sun Mar 17, 2019 1:45 pm

Joe, do make sure your gas fitter friend can issue the approval certificate and name plate. My own domestic plumber/gasfitter had no idea. That's why I got a specialist in. These guys are not always easy to find, at least in Sydney.
If you need to know about mistakes Joe, my thread is a rich source.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Sun Mar 17, 2019 2:29 pm

Front equipment locker

The equipment locker at the front is now more or less complete.
I put in a panel to take the switches in front of the water heater using marine table lift-off brackets from Whitworths. I have left enough slack in the cables and air lines to enable this to be lifted out for maintenance.

Image

The panel contains the pressure gauge for both air bags and switches for a locker light, the compressor, manual over ride for the two LED reversing lights and a manual over ride for the dust fans. The four LEDs at the left are to indicate the suspension height, green for street and red for off road. I have waterproof proximity switches which I will install after it’s out of the garage and registered.

The Hydrastar electric over hydraulic unit has yet to go in and I am still undecided whether to shoehorn it into the locker or put it on the drawbar.

Image

The fuse and relay wiring for all of this stuff is complete in its enclosure and I have wired the WiTi in its own box underneath. This gives easy maintenance access. When I first connected the WiTi up it was at the end of the day and I did not realise that it had armed itself. Yesterday morning I came out and pumped up against the van and dropped a cartridge of silicone on the top of the gear locker and all hell broke loose – beeping horn, flashing lights and so on. I had to rush off, try to remember where I stored the actuator buttons and turn it off. I am sure the neighbours were less than pleased.

We were planning to get some friends together and turn the roof over today. But it’s peeing down rain here in Sydney, so it’s a day in front of the telly instead.

Keith

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Re: Keith's light weight off roader

Post by Collyn » Mon Mar 18, 2019 9:55 am

Keith

Re your pics associated with the caption

"I arranged for the gas lines to be enclosed in thick-walled automotive heater hose, which provides fantastic protection for the pipes. But they still have to be kept out of the way of rocks. The picture above shows the original installation with the gas pipe coming over the wheel arch, well inboard of the wheel and out of the way of rocks, then coming down to the underside of the floor up to the BBQ, which you can see on the next picture."

Is there any risk as the shock absorber rubber bushes compress and distort - of the steel washer and nut of that upper threaded section damaging that pipe directly above and marginally behind them?

That threaded section will move a fair way when you traverse (say)a cattle grid at speed.

Collyn
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Re: Keith's light weight off roader

Post by KeithB » Mon Mar 18, 2019 4:08 pm

Collyn, the picture is a little deceptive, The gas line, although in the wheel arch, is 280 mm inboard of the tyre. We needed extra width in the wheel arch to allow for the inboard shock absorber and maintenance access to the air bag. I'll put a rubber flap in front of the valve after the gas fitter has signed off.
There is a picture of the layout in the first page or two of this string.
Keith

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Re: Keith's light weight off roader

Post by Collyn » Tue Mar 19, 2019 11:36 am

Keith

I was not suggesting the tyre was touching it - but both pics look as if that upper shock absorber rubber bush is virtually touching the pipe.

When the shock absorber is suddenly fully compressed that bush extends circumferentially and upward at considerable force.

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Re: Keith's light weight off roader

Post by KeithB » Tue Mar 19, 2019 3:29 pm

Yes the picture is very misleading and it's a bit hard get a better one because of the restricted space. The inner shock absorber bush is three inches away from the pie and three inches below it.
But I still think the valve will need some protection from rocks.
Keith

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Re: Keith's light weight off roader

Post by Collyn » Wed Mar 20, 2019 8:18 am

The trajectory of stones and rocks thrown up when traversing corrugation is extraordinary.

Whilst living in the Kimberley we'd visit the east coast at least once a year - mostly via the 1000 km Tanami - of which 800 km back then was dirt. The OKA took quite a pounding - particularly the rear shock absorber bushes. We needed to replace them every second trip (13,000 km return). Ditto our later Nissan 4.2 litre TD Patrol and TVan.

Collyn
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Re: Keith's light weight off roader

Post by KeithB » Wed Mar 20, 2019 4:31 pm

"The Hydrastar electric over hydraulic unit has yet to go in and I am still undecided whether to shoehorn it into the locker or put it on the drawbar."

I was advised on another forum to check whether the hydrastar electric over hydraulic unit was waterproof. so I called them.
It seems that the main cable gland is not waterproof and there is a vent hole in the cap. So I will see if I can squeeze it into the locker. Otherwise it's no water crossings for me.

On other matters I have finally found a pair of slides that look to be of industrial quality for the slide out bed. The ones I have are a total failure, even though they are working well below their claimed weight rating. I chased up a recommendation from another forum which led me to the local distributor. But the slides are outrageously expensive at $2,260 a pair. so I'm scratching my head on that one.

Keith

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Re: Keith's light weight off roader

Post by Collyn » Wed Mar 20, 2019 4:50 pm

How heavy is the bed - I ask as there is a good price under chassis spare -wheel carrier on the market - and many such wheels weight over 50 kg.
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Re: Keith's light weight off roader

Post by KeithB » Wed Mar 20, 2019 6:26 pm

Collyn,

Thank you for the suggestion.
The bed is fully enclosed, with roof and walls and a an enclosed drawer/locker section underneath. With the aircon, pull-out drawers, retractable bed base and hardware attached, the slide out bed is about 125kg max. If we add bedding, clothes in the drawers and a bit of stuff in the rear lockers, we will be as much as 170kg. When we are in it the support legs will be down, so the live weight is not an issue. There is no room to run two sets of slides to share the load.
I am looking for full extension drawer slides with 1450-1480 extension and a load rating in excess of 300kg and a maximum width of 19mm.
There are plenty of slides out there, but they are all too wide - except for these multimillion dollar ones, made by Timken in Italy.
The ones I got from IRS are rated at 227kg but they sag dangerously and wobble from side to side like nobody's business. I don't want to have done all this work only to have the slides let me down. As a last resort, I will spend the cash if it solves the problem once and for all. I and a couple of mates are searching the internet for a cheaper alternative.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Sat Mar 23, 2019 2:44 pm

More roof work.

All of the visible parts of the underside of the roof are now painted and the main roof seal is installed. I have used the commercial silicone refrigeration seal that may have been mentioned in an earlier post. It’s silconed down and screwed over that with 12x3 aluminium flat which is drilled and countersunk at 50mm centres. The stainless screws bight into the epoxy edge filler and hold quite well. Here’s what it looks like

Image

The corners of the seal were impossible to cut neatly so I partially filled them with matching (almost) silicone and pressed Gladwrap over them to get a good finish.

Image

I cut some panels from 3mm foam board for a ceiling lining. But it was a bit too drummy so I glued in some timber plugs to support it when it’s glued up. But I can’t do that till the roof wiring goes in.

Image

The chip shop filter finally arrived and its held in the some tabs from 20mm aluminium angle with two sets of rubber compression seal all around. The filter has drain holes at the corner and there are gaps in the front seal to let it drain. I tried a garden hose on it and a mist spray doesn’t get through. There is also a rubber compression seal around the perimeter of the cowl.

Image

The windows and door are now in and I’ll post some pics after the adhesives have gone off.
Keith
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Re: Keith's light weight off roader

Post by jailbar joe » Sat Mar 23, 2019 9:38 pm

coming together nicely...any progress is good progress :D
cheers
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Re: Keith's light weight off roader

Post by KeithB » Sun Mar 24, 2019 7:47 am

Too true Joe. There are no small victories.

I was a bit naive in believing that the 227Kg rating on the original slides was fair dinkum and I've really painted myself into a corner on this slide issue. I should have known that there would be tears before bedtime. This build is starting to wear me out a little and I just want to get it finished and on the road without any more nasty surprises.

After an intensive search of manufacturers all over the world, it seems that these Rollon slides are the only ones that will do the job. And at least I can expect a trouble free run down the track. This is a very expensive build anyway and I expect to be able to insure it for at least twice the build cost. That's enough of my justifications. I really don't think I have any option other than to fork out the dough for these industrial slides and wait six weeks for them to turn up.

https://www.motiontech.com.au/wp-conten ... 0319-1.pdf

Meanwhile here are a few more pics of progress.

The composite panel is only 15mm thick and the Camec doors and windows need a panel 27mm thick. So I had some spacers machines up out of 12mm low density PVC.
Here's what they look like after fairing and painting.

Image

Image

I glued them onto the walls with epoxy and then fitted the windows and door in the normal way.

Image

Today I am laying out the positions for the solar panels and clearance lights on the roof.

Keith
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Re: Keith's light weight off roader

Post by Collyn » Sun Mar 24, 2019 2:12 pm

Keith

It should be feasible to save a lot of weight re the mattress.

I will email you the draft of an article that I shall eventually have on my website - it is of a totally extraordinary fully-off road tiny motorhome with pop top roof mini-slide out, inside shower and loo etc. The entire body and its interior (fitted on a Nissan Navara chassis) weighs under 375 kg. Is ultra-high tech using a fair amount of carbon fibre.

The builder (a Sydney-based environmental architect) spent several years and work in designing and self-building - including experimenting with a minimal weight (and totally ventilated) bed and mattress.

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Re: Keith's light weight off roader

Post by KeithB » Sun Mar 24, 2019 3:06 pm

Thanks Collyn. I'm on it.
We are planning a laminated foam mattress anyway, but I really like the idea of the breathable underlay.
Cheers
Keith

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Re: Keith's light weight off roader

Post by KeithB » Wed Mar 27, 2019 5:25 pm

Solar started

Got the solar panels nailed down to the roof today. Fitting these thin wall solar panels is complex and Solar 4 RVs has issued quite detailed and specific instructions on how it’s to be done. It seems that there are two problems if you stick them straight down onto the roof;

1. They get too hot and loose efficiency; and
2. They move differently to the substrate due to thermal expansion and ultimately fail. This has been a big problem on Kimberley Karavans.

So we start out with little strips of ribbed polycarbonate roofing which has to be cleaned with isopropyl alcohol and then a special tape applied. Solar 4 RVs say they have tested many tapes to failure and this this 3M product is the stuff to use. Here’s what the strips look like with the tape on:

Image

Then you clean the panels once more with the alcohol and stick the strips down between the rows of solar cells. I put each solar panel onto a glass table with a light below so that I could locate the strips accurately between the cells. Here’s what we get;

Image

Doing all of this for nine solar panels meant 100 strips and took a full day. Today we stuck the panels down:

Image

Image

I am hoping that these panels will form something of a tropical roof and will keep the caravan a bit cooler. Next job is to fit the waterproof fittings through the roof – all 18 of them plus do the running lights on the roof.

Keith

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Re: Keith's light weight off roader

Post by Collyn » Fri Mar 29, 2019 1:01 pm

Whitworth has a range of these (including for ocean-racing yachts).

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Re: Keith's light weight off roader

Post by jailbar joe » Fri Mar 29, 2019 6:07 pm

wow .....here i was thinking my little van was over complicated (for me) i would be so far out of my depth on this
one for sure.

you seem to be flying into it keith,well done
cheers
joe


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Re: Keith's light weight off roader

Post by KeithB » Fri Mar 29, 2019 7:00 pm

Quote from Joe: ".... wow .....here i was thinking my little van was over complicated (for me) i would be so far out of my depth on this one for sure. "

Joe, so am I. Totally out of my depth in fact.
Thanks for the heads up on Whitworths Collyn. I am fortunate in having a marine electrician, a good local builders hardware, a Bunnings, Whitworths and aJaycar all within 5-15 minutes of home. Every one of them has given my credit card a pounding.

Keith

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Re: Keith's light weight off roader

Post by KeithB » Sat Mar 30, 2019 3:32 pm

Awning and wheel arch

I have a 3.3 metre Thule motorised awning to go up on the roof skirt and it made sense to dry fit it while the roof was sitting on stands. This 27kg unit comes with two support brackets, one for each end about 150mm wide and one about a third that size for the middle. I was worried about too much load on the skirts concentrated on small parts of the skirts, so I ordered some optional brackets which are 400mm wide.

The awning hangs self-supporting on the brackets and is secured to them with a load of pop rivets. The awning will go on permanently when the caravan is in the street.

Anyhow I clamped some timber battens to rest the brackets on so that they were all in a straight and level line, ready to bolt through onto the roof skirt. But it turns out that the roof has a 2mm belly in it and bolting the brackets straight on would not work. So I put them up like you would a wall tile, using a very big bed of epoxy adhesive and tapped them true to a couple if string lines and through bolted them after the epoxy had gone off. Here’s what they looked like and please excuse the lousy focus.

Image

I think the belly in the roof skirt came because it follows the wall. And the wall was a bit out due to the tight fit of the fridge which pushed the wall out a touch, courtesy of Evakool publishing incorrect dimensions and finding themselves unable to provide an accurate general arrangement drawing. But I digress. Here’s what the awning looks like sitting on the brackets.

Image

We did fix one annoying thing though. Back on a previous page is a picture somewhere showing a bunch of Tek screws that hold aluminium strips to support the rubber wheel flares. There were temporary and needed to be replaced with something better as they sit right above the tyre tread. So we took them out, countersunk the holes, back filled with adhesive and put in flush mounted marine grade screws, which look a lot better, won’t rust, catch rubbish or schred a tyre if the suspension collapses.

Image

All of the through fittings for the wiring have arrived so I can start wiring the awning and solar panels. The longer exhaust pipe for the diesel heater has turned up as well. So there is plenty of work to do.

Keith

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Re: Keith's light weight off roader

Post by KeithB » Sun Apr 21, 2019 4:45 pm

The last few weeks have been a bit slow on the World’s Slowest Build, largely due to Old Man’s issues. But we’ve got a few things done.
The doors and windows are in, but the radius we cut for the door opening was too big and left a 20mm gap in the corners that had to be filled, faired and painted. Looks good now. Also touched up a bit of paint damage here and there from all of the clamping to set the roof. I have also cut the panels to line the ceiling.

SOLAR

The solar panels now have all their wiring secured and waterproofed through the roof with the entry glands held down with Sikaflex. I’ll waterproof the roof holes with Sikaflex from the underside.

Image

Per the manufacturer’s recommendations I have also epoxy glued a bunch of safety clips to the leading edge and sides of each panel in case the double sided tape lets go, which Solar 4RVs says has never actually happened. I used 15mm PVC Gyproc edge strip cut into 40mm pieces and glued around the edges. On a few spots I glued some PVC angle to the cable glands to help secure the leading edges.

Image

I wondered about what connectors to use for the solar on the cowl and the cables for the dust fans, awning and lighting. I decided to use standard 7 pin trailer fitting as they are cheap, reliable and easy to replace. Here are the connections that go under the cowl.

Image

And here is the connection for the motorised awning. The loose wires you can see are for the awning light.

Image

Roof Vents

We can’t have zip out windows in the bathroom because of the proximity of the gas bottles and the need for privacy. So I decided to go with some small roof hatches for light and ventilation. Because these hatches cop all of the wind, rain, dust and insects, I went with two Bomar marine hatches. They are much more expensive that flimsy caravan vents, come with internal trims and flyscreens and sit almost flush with the roof. Here they are loosely in place.

Image

Because they need a 25mm panel thickness I have ordered two cutout surrounds to go on the outside rather than go butchering the hatches. They will arrive in ten days and will need fairing and painting before they go in. I've reached my 6 picture limit so will start a new post.

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Re: Keith's light weight off roader

Post by KeithB » Sun Apr 21, 2019 4:47 pm

Just continuing on from my earlier post:

Heater exhaust

I mentioned in an earlier post that the heater exhaust is too close to the gas bottles. So in pulled it out, patched the hole in the side of the locker and rerouted it through the floor towards the back. Here’s what the locker view looks like.

Image

The thing is as noisy as hell so I wrapped the exhaust pipe in some glass tape, which did not help much.

Image

The heater, with a Chinese Belief furnace is extremely noisy for 10-15 minutes after it starts up and I’d hate to be camped next to myself in a caravan park. I understand that Webaso units have the same problem. So I have ordered a muffler to suit a Briggs and Stratton 7Hp motor to see if that helps. Also on order is a spacer panel to take the locker door half in inch further out to make room for some heavy marine sound proofing for the inside of the plastic locker door. Other than that, I am buggered as to what to do for now anyway.

Putting the roof pack on.

Tomorrow is a big day. We have organised a bunch of friends and neighbours to come and help lift the roof onto the caravan tomorrow morning. It’s going to be a tight fit to get it between a big steel beam in the garage roof and the top of the van without bashing any of the solar panels.

I preparation, I lowered the caravan to get maximum clearance. In doing so I didn’t notice that one of the spare wheel carriers that I had cut of was still under the van and pointing ominously upwards. When the van wouldn’t drop down I went looking and found that the top edge of the wheel carrier which you can see here, was pressed up against the lower surface of the rear water tank and supporting about 40% of the weight of the van.

Image

So I raised the van and inspected for damage. There is a very small indent in the outer surface of the composite with no cracking and no penetration into the honeycomb. A bit of filler and it will be as good as new. Goes to show how strong this composite material is.
The other good news is that the million dollar slides arrive the day after tomorrow.

Keith

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Re: Keith's light weight off roader

Post by KeithB » Mon Apr 22, 2019 11:08 am

The roof in on at last!

We had a bunch of neighbours come around this morning to help lift the roof on. In basket-weaving chardonnay-sipping Balmain, it’s the nearest you can get to a barn raising.
It went on okay but I had to trim about 6mm off the leading corner of the front awning bracket to clear the roof beam.

Image

Image

Image

It still needs to be centred by about 10mm to make it fit nicely. But the seal has settled well all around and, just looking at it, I think it will come out of the garage without having to remove the roof. The main roof hatch and the awning will go on when it's in the street.

Today has been a real milestone. Happy days!

Keith

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Re: Keith's light weight off roader

Post by Lance » Mon Apr 22, 2019 3:51 pm

Ripper Keith, you've been a tad concerned about that roof, well done to all your helpers.

Ya needa biga garig mate :lol:
Lance & Anne
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Re: Keith's light weight off roader

Post by KeithB » Mon Apr 22, 2019 4:17 pm

Lance I am in a state of perpetual shed envy. But this build is in Sydney's Inner west where hardly anyone has a garage at all.

Meanwhile this heater noise is driving me crazy.

If you or anyone else has got any ideas on quietening this heater, I'm all ears. I can't use anything with a lot of flow resistance on the exhaust and I don't know if the muffler I have ordered will work or not.

The exhaust pipe is 1 inch convoluted stainless steel, which is not all that great for smooth flow and has a length limit of 1500mm for that reason. I was wondering about rolling up a pipe out of bronze mesh, surrounding it with fibreglass wool, putting a metal surround over that and using it to replace the existing exhaust pipe.

Would that quieten it down? These measurements we taken inside the garage and should be a bit lower outside. Here's where we are at:

Background noise: 43dba
On warmup no hatch in the locker at 12 inches: 85dba
Ditto with hatch in locker (not sealed, just pressed in and no sound proofing): 74dba
On standby no hatch: 65dba
12 inches from exhaust on warmup: 85db

85 dba is about the same as heavy traffic, a noisy restaurant, a diesel truck passing, a lawnmower or a freight train at 100ft and so on. You get the drift. The problem is that every time you have a shower or turn the fan heater on, it goes into blast mode. I had no idea it was going to be this noisy and I simply have to fix it. There's no space to insulate the inside of the locker, other than the door face.

I suppose I could build another box around the locker, but that's a shipload of work and won't address the exhaust noise.

Keith

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Re: Keith's light weight off roader

Post by Collyn » Mon Apr 22, 2019 5:07 pm

Keith

As you will be aware this can be quite a problem due to the log power law involved and that there is often more than one cause. Fixing that may then reveal another that it was masking. By far the best sound shielding is loosely held sheet lead. Or the sheet bitumen product from Whitworth.

Alternatively is it too late to replace it by the Webasto LPG or diesel air and water heating unit? Still bit noisy at about 71 dBa at 7 metre - but not absurdly so.

Collyn
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Re: Keith's light weight off roader

Post by GerryP » Mon Apr 22, 2019 6:52 pm

Keith, we have one of these cheaper units and are pretty happy with the noise levels. Yes, it starts up full chat and while the noise is noticeable, it doesn't last long before it settles down. Once it gets to that stage you hardly hear it.

Perhaps your crowded shed is amplifying the noise? I have a supplied muffler and have wrapped the exhaust with heat proof exhaust tape, but mainly because it's close to a water tank.

May I suggest that perhaps you don't worry too much more about it until you get the van out in the open and away from nearby sound reflective surfaces.
Cheers, Gerry
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Re: Keith's light weight off roader

Post by KeithB » Mon Apr 22, 2019 8:13 pm

Thanks Collyn and Gerry.

I am a great hater of generators in camping areas and can't live with the fact that I could be an offender. When the heater is on standby and just keeping the towel rail warm, it is reasonably quiet. But if we want to use it to run the fan heater at night, the noise will be a problem, particularly for other campers. This heater does not come with 240 volt element option, but we can use the aircon for heating in really cold weather if we in a caravan park.

I do take your point about the garage raising the noise level though. But Collyn's quoted figure of 71dba at 7 metres is still a bit much for me. Changing the unit is not an option at this stage. I have used the Whitworths stuff to good effect and am picking up some of this other stuff tomorrow for the plastic hatch. The exhaust pipe might be a bit too hot for this stuff.

https://www.roadtechmarine.com.au/engin ... e/p/MGA100

I'll have a play with making up a long straight through muffler, if only for the intellectual exercise.
Keith

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Re: Keith's light weight off roader

Post by Collyn » Tue Apr 23, 2019 11:57 am

Keith

I've had two of the Webasto units - one in our OKA and the other (a Dual Top unit) in the TVan.

They could not be heard inside the units and not inside an RV by anyone nearby. They do not appear to be an issue even in quiet campsites. (I did use silencers on both inlet and outlet and mounted the units on rubber.)

I too wonder if the issue is that you have it in an enclosed smallish space that reflects sound - and possibly causing harmonic and sub-harmonic resonances in that space?

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Re: Keith's light weight off roader

Post by KeithB » Tue Apr 23, 2019 1:56 pm

Thanks Collyn. I do hope that I don't have a harmonic going on and am hoping that my noise measurements in an enclosed space have mislead me.
A video on Youtube was recommended to me that highlighted the difference in performance between to types of mufflers that you can get.

https://www.youtube.com/watch?v=hj8da4WQaac

They look pretty much identical; but one has a dog leg inside and the other is straight through. I have one dog leg type on the heater now. Contrary to what anyone might think, the straight through one works a lot better and the tester got a 10dba reduction by using two in series. So I have ordered four of those mufflers at an affordable $13 each to try out. It's a lot easier and cheaper than fabricating something. I'll keep adding mufflers until I either get no noise benefit or a smoky exhaust.

I picked up some really good marine insulation this morning for the plastic door which claims a 27dba reduction when used in engine compartments. There is no space to get more insulation around the inside of the equipment locker which, I mentioned some time ago, that I have made way too small.

I also picked up the multi-million dollar slides this morning and I can see why they are so expensive. They are beautifully made and all machined out of solid material, rather than roll formed stuff. They are a bit heavier than the other ones though and I'll have to live with that.

I'll pull the aircon units and the steel drawers out of the slide-out this afternoon and remove the gate in preparation for the slide replacement, which will be a big job that I am not looking forward to. All new holes to drill, back fill with epoxy, glass over, fair and paint.

Keith

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Re: Keith's light weight off roader

Post by Collyn » Wed Apr 24, 2019 8:11 am

It all seems like Sisyphus - without the causal sin!

Hopefully it stays at the top of the next hill!

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Re: Keith's light weight off roader

Post by KeithB » Thu Apr 25, 2019 5:33 pm

Slides

After a great deal of mucking around, I got the old slides off today and filled the old holes with epoxy filler. They were held onto the body with 8mm dome head bolts with flat washers, spring washers and Nylock (if that’s the correct spelling) nuts plus a dab of blue Loctite. Several of them had seized and I had to do a fair bit of butchery to get them out.

Luckily, the old slides won’t be reused anywhere because they are cactus. They have been loaded at well under their quoted 227Kg rating and are spewing ball bearings and bits of plastic ball cage without the caravan having moved anywhere. They are deflecting at the end by 70mm with the aircon and steel drawers removed from the sleeper. The data from the Timken Rollon slide company allows you to calculate the deflection which I think will be less than 25mm.

Here’s a shot of the old failed slides on the left and the new multimillion dollar ones on the right. The old ones have a slide within a slide against a fixed base. As the slide extends the whole shooting match gets thinner.

Image

On the left you can see where the end of the outer and inner members have failed allowing bearings to spew everywhere. On the right you can see the multimillion dollar slides. They don’t have a slide within a slide. They have an intermediate slide which goes half way out and allows the smaller section to extend. Unlike the nasty slides, they are reversible and have countersunk 5mm countersunk attachments at 80mm centres along their entire length.

Both types of slides weigh the same. So I guess you get what you pay for. Now to fit them. In order to get the seals to seat properly I have only a1mm or so of tolerance. Wish me luck on that one.

Keith

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Re: Keith's light weight off roader

Post by jailbar joe » Wed May 01, 2019 10:17 pm

okay...goodluck keith.....they sure do look robust,i hope they do the job and serve you well :D
cheers
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Re: Keith's light weight off roader

Post by KeithB » Sat May 11, 2019 6:26 pm

Brakes and Slides

Brakes

Because the brake callipers had been laying around for years, I sent them out to be reconditioned and they are back in place. The Hydrastar electric over hydraulic unit is in, squeezed into the front locker, complete with breakaway switch and is working fine.

Image

I bled the Hydrastar unit no problem. But I couldn’t bleed the sponginess out of the calliper lines. As it turns out, I had installed the callipers on the front of the disks instead of the rear, to make connection of the hydraulic lines a little easier. But I had stuck with putting the left hand calliper on the left side and so on, which meant the callipers were upside down with the bleed screws at the bottom of the calliper instead of the top.
So I’ll swap them over and bleed the system again.

Slides

I have been mucking around with these new multi million dollars lides for the last couple of weeks. The problem is to get the slides in with the slide-out in exactly the right position, up/down, sideways and absolutely plum so that the rear panel slides into place onto the seal perfectly when the slides are loaded. I have jacked up, wedged up, put in temporary timber runners, done a lot of scrotum scratching and measured a thousand times before being happy that it’s right. Is it’s not, the caravan will fill with dust.

There is a nice video in Italian with subtitles that tells you how to install the slides with a charming gent named Mr Tosi.

https://www.youtube.com/watch?v=zpsVpb1 ... sVpb1uvMU

If I was installing these slides with 360 degree access like Mr Tosi in the demo, all would be fine. But it's not.
I pulled out the old slides, filled all of the old holes, established new holes reinforced with epoxy and put on some paint.

Image

We have a fixed upper rail, an intermediate sliding rail not fixed to anything and a lower rail which is fixed to the slide-out. Mounting the fixed ends of the slides onto the caravan was easy enough, with the outer five screws being drilled and installed through factory holes in the intermediate sliding member.

Image

With the slide-out accurately set on blocks in the out position, you then extend the sliding lower rail and place ten screws onto the slide-out with all of the boring out, hole filling with epoxy, redrilling and so on that goes with that. Below you can see the five holes in the intermediate member that you drill through to fit the last five screws on the fixed rail on the caravan.

Image

Then comes the problem. We come to think about the five screws that have to be installed into the slide-out through the holes in the intermediate member at the closest end to the caravan.
It seems that the only way I can get access to these holes is to slide the thing in, at which time the holes are inaccessible because they are covered by the body of the caravan, adjacent to the when arch, as well as the slide-out itself.

So it looks like I will have to slide the thing in, mark the position of the lower fixed rail and intermediate slide and the mark and drill some holes into the wheel arch on both sides through the intermediate member so that I can push the screws in from underneath, inside of the wheel arch. When they are all in, I fill the holes in the wheel arches, glass over, fair and repaint.

Wish me luck with that.

Keith

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Re: Keith's light weight off roader

Post by jailbar joe » Sun May 12, 2019 9:49 pm

and i thought i was beating myself up with some of the crazy stuff i do.......

can't be of any worthwhile assistance other than to wish you a lott of luck...if i was praying man i would pray for you,
i don't know if there is a translation service that applies to youtube like there is for emails....maybe the hard part is verbal
in the clip ??

i hope it comes together soon for you and the solution is not to hard to arrive at.

goodluck keith
cheers
joe


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Re: Keith's light weight off roader

Post by Collyn » Mon May 13, 2019 1:12 pm

Re: praying

Don't!

A medical study showed a minor negative correlation - so if he/she/it is listening 'whatever' may be marginally anti (or the 'error' is within the relevant standard deviation!)
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Re: Keith's light weight off roader

Post by KeithB » Tue May 14, 2019 10:18 am

Collyn wrote:
Mon May 13, 2019 1:12 pm
Re: praying
Don't!
A medical study showed a minor negative correlation - so if he/she/it is listening 'whatever' may be marginally anti (or the 'error' is within the relevant standard deviation!)
Collyn
With the total absence of Divine intervention, I think I have found a solution by drilling just one hole in the wheel arch. I managed to get five screws and a shim into one side, with the assistance of skinned knuckles and the liberal use of carnal verbs and lower pelvic nouns. Will post some pictures once I see it actually working. May take a day or two for the epoxy to go off in this cool weather before I can test the newly installed slides.

Keith

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Re: Keith's light weight off roader

Post by muzz_on_line » Tue May 14, 2019 12:49 pm

Hello Keith

You have made my day.
with the assistance of skinned knuckles and the liberal use of carnal verbs and lower pelvic nouns.
I have nether heard it said (written) so eloquently before.

To think that I thought your build was great, your use of the English language has trumped it with spades.

May have to quote you once in a while. :mrgreen:

Muzz

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Re: Keith's light weight off roader

Post by Collyn » Tue May 14, 2019 2:18 pm

Potis anomala verba sinelapsu declinare . . . !

Collyn
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Re: Keith's light weight off roader

Post by KeithB » Tue May 14, 2019 2:53 pm

Thanks Muzz. Your words are very kind.
Collyn wrote:
Tue May 14, 2019 2:18 pm
by Collyn » Tue May 14, 2019 2:18 pm
Potis anomala verba sinelapsu declinare . . . !
Collyn
Good Heavens Colin.
You have offended my lifelong commitment to avoid big words like "corrugated iron".
To make matters worse, my four years of studying Latin (if that's what it is) in the 60's have long deserted me. Along with a good number of other facilities which have lamentably followed suit.

Keith

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Re: Keith's light weight off roader

Post by Collyn » Tue May 14, 2019 3:12 pm

Mea Culpa!

It credits you not just with getting that hole right - but 'the ability to conjugate irregular verbs without making a single mistake'.

People who mess with Latin
Should be put in a vat with some fat in
And put on to boil
With plenty of oil
And left there from Vespers to Matin.

Collyn
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Re: Keith's light weight off roader

Post by KeithB » Tue May 14, 2019 5:41 pm

Ten screws in two days!

Collyn, irregular verbs should eat more fibre.

After many lamentations and much wringing of hands, the ten inner screws are in at last. It took two days.
I had a bad start because the sleeper was tipping forward a little bit and wrecking the alignment of the back wall against the seals. So I used some refrigerator slides that were lying around and packed the front up so that I could move the sleeper in and out while fitting the slides, without interfering with the fit at the back.

Image

The method was to drill a one inch hole in a strategic spot in the inner wall of each wheel arch, which you can see in the picture above. I didn’t mention earlier that the slide had to be shimmed out by 2mm on each side as it is thinner than the original one. I had already put some 1mm thick washers behind the fixed slides, but it wasn’t nearly enough. So I cut a piece of 2mm fibreglass from some epoxy angle and match drilled it to the holes in the slides. Here is one of the two shims. I had already done the same on the back ten screws.

Image

The tricky bit was to position the intermediate slide over the hole and then mark it and make sure it couldn’t move. Then move the sleeper in and out, climbing under the wheel arch each time, until the appropriate screw hole could been seen through the wheel arch wall and the intermediate slide. This wasn't easy because the suspension is right down on its haunches to that the caravan can clear the ceiling. Then, holding everything very steady, you insert the shim piece and slide it along until the appropriate hole in the shim can also be seen through the wheel arch. That means the three are lined up.

Then you drill through from under the wheel arch and open the hole from the other side with an 18mm spade bit. Then you push the screw through from the wheel arch, fill around the screw from the inside with epoxy putty and pull it down with an oversized washer, spring washer and a Nyloc nut. Each one took over an hour, once I got the hang of it.

Here you can see the screws in place on an epoxy bed with the one inch hole to the left of shot.

Image

I think I will make up a flush mounted removable plug for these holes for future maintenance access. Tomorrow morning I’ll put a fan heater in there to help the epoxy go off properly, torque up the screws, cut off the excess and put the drawers back. Provided of course that the slider still does as it’s told.
Then it’s back to more wiring.
Keith

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Re: Keith's light weight off roader

Post by jailbar joe » Wed May 15, 2019 9:28 pm

good to see you have beaten it keith....there is a lot to be said for profanity....without it i don't think
many projects would be completed

at least from here on it should be easy :mrgreen:
cheers
joe


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Re: Keith's light weight off roader

Post by KeithB » Sun May 19, 2019 3:29 pm

Dunno about easy Joe, but I'm hangin' in there.

Anyone got any noise reduction suggestions?

I spent a little time today seeing what I could do about the heater noise. Here is the current exhaust setup with a muffler inside the locker at the front with the heater.

Image

Yesterday I installed the locker door with some really good marine insulation on the inside of it. There is no space to do the rest of the locker. I also tentatively added two more mufflers onto the back end of the exhaust, which did not cause any smoke, to see what would happen. Here are the current results:

Background noise: 50dba (43 last time)
On warmup with hatch in locker closed and soundproofed: 72dba (85 with no door last time)
On standby door closed: 55dba (65 last time with door open)
12 inches from exhaust on warmup: 82dba (85 last time)
12 inches from exhaust on standby: 54dba (not measured last time)

There is a marginal improvement but still quite bad. The changed background noise should not have had much effect, except for the standby figures. I think I'll reinstall with four mufflers and see how it goes. It may be a lot better when its out of the garage. I might have to revisit the problem after it's registered. In the meantime, I'd appreciate any noise reduction suggestions.

Meanwhile, the new slides are in and working very nicely; but there's no real weight on them as yet, because the aircon brackets are out being modified. I have also fitted a door to the rear locker on the slide-out and made a start on the bathroom hatches as well as the slide-out wiring. More pictures soon.

Keith

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Re: Keith's light weight off roader

Post by GerryP » Sun May 19, 2019 7:35 pm

Keith, I'm not quite sure, but are you measuring on startup, or are you letting it run for a while and then checking? The reason I ask is that our heater (and I believe they're all very similar) is much noisier when it first starts up. It starts 'flat out' and then winds back, over a short while, to a very quiet idle. When ours has been on for say 15 - 20 minutes, you can barely hear it running from outside. One of our travelling buddies has a Webasto and it's much the same as our Chinese unit.
Cheers, Gerry
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2018 New Age Manta Ray 18'

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Re: Keith's light weight off roader

Post by KeithB » Sun May 19, 2019 7:38 pm

Gerry I am measuring on startup. That's because the heater furnace will be running a fan heater inside during cold weather and I expect it to be cycling on and off quite often. But time will tell.
Thanks for your comments.
Keith

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Re: Keith's light weight off roader

Post by GerryP » Sun May 19, 2019 7:47 pm

Keith, ours doesn't seem to cycle, but rather it just drops down to a slow idle. If it cycled, then it would need to energise the glow plug each time and that uses quite a bit of energy. The combustion air fan and the room supply air fan are both on the one motor, so as the unit idles down, so does the internal, as well as external fan noise levels. However, most of the noise on startup is the noise of combustion. If you monitor the fuel pump 'ticks', you'll hear the difference in combustion noise as it speeds up and slows down.
Cheers, Gerry
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Re: Keith's light weight off roader

Post by KeithB » Sun May 19, 2019 8:58 pm

Thanks again Jerry. So it does look very much like I am worrying needlessly.
I'll report back on how it goes in the field.
Keith

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Re: Keith's light weight off roader

Post by J.REEVES » Sun May 19, 2019 9:06 pm

Hi Keith,
Just to clarify you are using a diesel HWS and room heater all in one unit aren't you which is not quite the same as the standard diesel heat?

I have fitted a couple of Chinese diesel heaters for friends and one heater came with no muffler. I was surprised that when we ran it the exhaust noise level was almost the same as the heaters with a muffler.

Does that insulation material on the exhaust help reduce any noise?
What kind of room heating output does the heater have and can it run at different outputs?
The basic diesel heater output on max is usually about 2000 to 2200watts but can drop to a very low output. If the heater does require to cut in and out the outside temperature is not really that cold and you probably don’t need it to be in service.
As said the standard diesel heater once up and running and reached temperature set point cuts back and is not really noisy (in my opinion).

Some things that can help the standard diesel heater run quieter:
There are some combustion air intake type mufflers and some people mount the fuel pump in a box lined with sponge and mount the box to the chassis so the pump is suspended in sponge so there is no physical attachment to the chassis.
I have no experience with the diesel heater/HWS so it maybe noisier than the stand alone diesel heater.

Keep up the good work and stop blaming yourself if something goes wrong, leave that for when you get older!

JR
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Re: Keith's light weight off roader

Post by KeithB » Sun May 19, 2019 10:21 pm

John, thanks for that. Just to clarify:

My system consists of a Belief furnace which pumps through a reservoir of coolant with a coil inside it to heat the hot water. Before the coolant returns back to the reservoir it splits into two circuits, each with its own manual control valve. One circuit goes through the towel rail in the bathroom and the other goes through a fan heater in the saloon area, with both returning to the reservoir through a common line. The fan heater has a two speed fan and a thermostat control plus a manual over ride of my own design, plus an tiny auxiliary coolant pump to help it out.
Here's what it looks like.

Image

The furnace is rated at 4Kw and the fan heater at 1.7Kw. The towel rail uses almost nothing.

I have fitted a couple of Chinese diesel heaters for friends and one heater came with no muffler. I was surprised that when we ran it the exhaust noise level was almost the same as the heaters with a muffler. Three mufflers for me seemed to be a little quieter than one.

Does that insulation material on the exhaust help reduce any noise? I don't know is it does because I haven't tried it both ways.

What kind of room heating output does the heater have and can it run at different outputs? See above.

The basic diesel heater output on max is usually about 2000 to 2200watts but can drop to a very low output. If the heater does require to cut in and out the outside temperature is not really that cold and you probably don’t need it to be in service. True. In fact I'd close the coolant control valve to the fan heater when it is not needed.

As said the standard diesel heater once up and running and reached temperature set point cuts back and is not really noisy (in my opinion). Good news.

Some things that can help the standard diesel heater run quieter:
There are some combustion air intake type mufflers and some people mount the fuel pump in a box lined with sponge and mount the box to the chassis so the pump is suspended in sponge so there is no physical attachment to the chassis.
Mine is on a wobbly rubber mount with flexible lines and is barely audible. I have not fitted the inlet air silencer yet and I need to relocate one of the mufflers to make space.

I have no experience with the diesel heater/HWS so it maybe noisier than the stand alone diesel heater. I hope not.

I'll do some more testing over the next few days.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Mon May 20, 2019 9:08 pm

An old uni mate of mine, who is also a retired engineer, is a very fine furniture maker, which is his hobby. Turns out the most amazingly beautiful stuff.

He has agreed to make the nine kitchen drawers for my caravan build. I was concerned about weight so I asked if he could make them from paulowinia, because if its light weight. He got back to me today.

"Keith," he said, "that poulowinia is not much better than balsa. It's furry and you can't get a finish on it. So we're making them out of Australian cedar. It's only twenty per cent heavier."

Wow! You could have knocked me over with a feather. It's going to be a very large bottle of Scotch (perhaps a case) for this most excellent and generous of mates.

Keith

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Re: Keith's light weight off roader

Post by KeithB » Wed May 22, 2019 6:42 pm

Heater noise

Thanks everyone who commented: you are right. The noise should not be a problem after all.
The first time I fired the fan heater up, the thing went into startup mode with the associated noise. But I have since started the furnace up on two occasions , let it settle down to standby and them turned the fan heater on. It stayed quiet.
All that worry over nothing.
Thanks for your help.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Sat Jun 01, 2019 4:23 pm

Solar cabling almost complete

I have finally got the cabling for the solar all run and connected, but the bus bars are not yet mounted.

Image

Here you can see the cabling for the solar panels with all the negatives on one bus to be wired to the solar controller and the positives on another. There will be separate removable heavy cables down to the controller. All the cables are marked with which panel they belong to.

There are also some other wires there for lights, dust fans and so on, which will go onto their own terminal strip with an earth back to the battery. The whole lot has to be shoe-horned into that little box thing that’s there. Then the ceiling lining goes on followed by a little locker door to give access to the bus bars.

All this fuss is to allow the roof to be removed.

The seals for the slide-out are almost finished and I’ll post some pictures when they are presentable. The slide-out is now pretty much weather proof. The aircon is in place after welding up the floppy support brackets and repainting them. Still waiting on the aircon man to come around so that I can finish the wiring inside the slide-out.

The end is in sight. But you have to stand on something to see it.

Keith

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Re: Keith's light weight off roader

Post by jailbar joe » Wed Jun 05, 2019 6:14 pm

thats a pretty impressive layout there keith...i'm glad i changed my mind about solar for mine...saved a few headaches for sure...

good to hear the end is in sight.....just hope its not to big a step to see it :lol:
cheers
joe


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Re: Keith's light weight off roader

Post by KeithB » Fri Jun 07, 2019 5:42 pm

Thanks as alway, Joe, for the encouraging words. Right now, a bloke could do with some encouragement.

More heater woes

We haven’t done much on the seals this week because the rain has prevented us working while the slide-out is out. But I hope we can get it all finished over the weekend.
The wiring on the roof is very complicated with cables all over the place. The trick is to install it so that the 24 cables between the body and the roof can be removed easily, should the time come to take the roof off. That’s about two thirds finished.

Meanwhile, the diesel heater has been giving problems. I reported previously that noise was no longer a problem. That’s because I have found that the furnace was cutting out. There is so much heat stored in the system that the fan heater and towel rail keep working for some time after the furnace dies.

The furnace runs for an hour or so and then turns itself off. Lovely and quiet but everything goes cold after a while. I tried lots of combinations with fan heater on high or low and control valves in different positions, all with the same result.

Today I wondered whether the heater was getting enough air with the locker door closed. So I ran it for about four hours with the locker door open. It was a lot noisier of course, but it didn’t cut out. Then I closed the door and presto, the furnace cacked its dax again.

So it looks like the furnace it either running out of air or the ambient temperature is getting too hot. I have contacted the supplier to see if there is an ambient temperature limitation on the furnace and am now running a little fan heater in front of the open locker door to see if I can make the furnace trip out. But it doesn't seem to be hot enough.

You can see from the pictures below that the little plant locker is pretty crowded. And the electric over hydraulic brake unit is going to add more heat to the equation.

Image

We have to air vents which you can seed below.

Image

They consist of two one inch black PVC pipes filled with 3mm cocktail straws compressed together and coated with oil to catch any dust. One goes down into the bottom of the locker and the other exits from to top. You can feel a little bit of warm air coming from the top vent when the furnace is running, but not much.
In am thinking aloud here and wondering if the suction fan on the furnace has enough grunt to pull air down through the tube filters and is tripping because it runs out of oxygen.

In either case I can add a little fan like this:
https://www.jaycar.com.au/97mm-x-94mm-1 ... e/p/YX2532
to the warm air exit (there’s no room on the other one) to come on whenever the furnace is running.

But I am mulling over another option, either to do on its own or in conjunction. The composting toilet has its own little computer fan that runs continuously to keep the loo under suction and to provide air for the compost bed. It draws its air from the bathroom, which has worried me regarding pressuring the van to keep dust out.

So I am wondering what would happen if I duct the loo air inlet into the locker and draw the air from there. That would have three benefits. It will supply warm air to help the composting. It will eliminate air leakage when trying to pressurise the van and it will draw fresh air into the locker. If the loo fan isn’t man enough I can upgrade it.

Much thinking to do.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Fri Jun 07, 2019 6:14 pm

CORRECTION:
After running the fan heater in front of the locker just now, with a towel covering the top half of the opening, the heater tripped out after an hour or so. So it looks like a temperature problem, rather than an oxygen problem.
Keith

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Re: Keith's light weight off roader

Post by Collyn » Sat Jun 08, 2019 12:41 pm

Essential to keep dust out (of RVs generally) is to remember to keep the sink and bathroom basin plugs firmly in place. As the RV moves up and down on its suspension the down bits pump dust into the interior via the plug holes!

Collyn
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Re: Keith's light weight off roader

Post by J.REEVES » Sat Jun 08, 2019 2:08 pm

Hi Keith,
Just wonder do you have a diesel heater controller that can display fault codes?
As yours is a HWS and heater there may not be a fault code.

I know that a straight diesel heater has high body temperature cut out and in fact if power is lost it is possible that the CPU can suffer heat damage as it needs the fan running to cool down.

Having two 1” inlets filled with 3mm cocktail straws compressed together and coated with oil may be just too much restriction for the heater. I believe that most diesel heaters use a fan that is basically just a fan and does not behave like a positive displacement fan/pump and so performance can be affected by the smallest of restrictions.

Sounds like you have proven this by leaving the door open.

JR
:razz:

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Re: Keith's light weight off roader

Post by KeithB » Sat Jun 08, 2019 3:02 pm

John,
I agree with you on the air restriction and am thinking of adding a little centrifugal blower that will come on with the heater. The challenge is to keep dust out and the noise in.
I have connected up the error reader control panel, relayed the results to the manufacturer and am waiting to hear back.
I changed over the fuel pump to a spare I had, but that made no difference.
When it trips out with the door closed it looks like the internal temperature is only about 40 degrees. The silver insulation on the door is only a few millimetres shy of the furnace body and may be reflecting heat back onto it.
Right how I have my workshop vac pulling air out of the discharge port to see if that solves the problem. Overkill I know. But it's all I've got.
This is very frustrating.
Keith

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Re: Keith's light weight off roader

Post by Collyn » Sat Jun 08, 2019 3:45 pm

J.REEVES wrote:
Sat Jun 08, 2019 2:08 pm
Hi Keith,
Just wonder do you have a diesel heater controller that can display fault codes?
As yours is a HWS and heater there may not be a fault code.

I know that a straight diesel heater has high body temperature cut out and in fact if power is lost it is possible that the CPU can suffer heat damage as it needs the fan running to cool down.

Having two 1” inlets filled with 3mm cocktail straws compressed together and coated with oil may be just too much restriction for the heater. I believe that most diesel heaters use a fan that is basically just a fan and does not behave like a positive displacement fan/pump and so performance can be affected by the smallest of restrictions.

Sounds like you have proven this by leaving the door open.

JR
:razz:
I think you may be right re this. We had a Webasto unit (in a small enclosure) in our TVan and had similar issues unless we left the lid open. We had no issues with dust damaging it - despite living in the Kimberley and almost always on loose dirt tracks. I feel the straws to be overkill.

Collyn
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Re: Keith's light weight off roader

Post by KeithB » Sat Jun 08, 2019 4:56 pm

I agree with you both on the straws. Definitely overkill. Strangely, the thing tripped out in less than an hour with my workshop vac sucking air though the closed locker while the fan heater was putting a bit of load on it. It was on standby all night with the door open, no problem. Have now been running for another hour with the door open and fan heater running and have just closed the locker door, with the straw-filled standpipes removed to see what happens.
We live in hope, in spite of the fact that Murphy was an optimist.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Sun Jun 09, 2019 11:19 am

The heater tripped out again last night. I restarted it with the locker door just open by an inch and was amazed at the amount of heat coming out the top of the door.
I have checked for exhaust leaks. I wonder is there is anyone who has successfully installed one of these heaters in an enclosed locker.
To make matters worse, if I start cutting holes in the locker to put some blowers in, I will fall foul of the LPG rules due the the proximity of an ignition source to the gas bottles. I'm not a happy camper right now.
Keith

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Re: Keith's light weight off roader

Post by J.REEVES » Sun Jun 09, 2019 11:58 am

Hi Keith,
Sounds like a bit of a problem. I know my diesel heater which sits under our kitchen lounge gets reasonably warm. In fact originally I covered the heated air ducting with extra insulation to reduce the trapped heat.

In all the years of travel on many dirt roads I never experienced heater problems due to dust until last year crossing the Gulf and the Great Central Road. Dust partly blocked a small air inlet around the glow pin which made the heater take two goes to start.
I have not done it yet but I will be fitting a dust cap on the combustion air inlet soon. My problem is access as the inlet is under the van and I just don’t wish to crawl under the van to fit and remove the cap so am thinking of lengthening the inlet to the side of the van. The gas heaters comes with a special cap to cover the combustion air and exhaust in and out.

You probably have the manual on you HWS/Heater but just in case.
The manual has 14 alarm codes on page 12 which you should be able to deduce from the number of flashes on the controller:
http://www.dieselheatingaustralia.com/w ... MANUAL.pdf

Looking at the manual the HWS/Heater construction is much different to the straight diesel heater.

Looks like you are going to need some kind of forced air cooling which will cut in when the heater is turned on. I expect you will only be running the heater when you are stopped so could have a cover over the forced air inlet and outlet and remove before starting. Possibly direct the two pipes away from the gas bottles but that does not look to be a real problem anyway, I am not a gas rules expert. Maybe increase the pipe size to 2” once you are sure this is the problem.

JR
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Re: Keith's light weight off roader

Post by KeithB » Sun Jun 09, 2019 4:09 pm

Thanks heaps John.
I can't find my original manual and am trying to figure out the little plug-in control panel. The manual you sent is a big help.
Jaycar have a nice little centrifugal blower that will push 1 inch water gauge and will do 740 litres a minute at free flow.
https://www.jaycar.com.au/97mm-x-94mm-1 ... e/p/YX2532
I might make up an adaptor and see what it can push through the one inch pipe, before butchering everything to install bigger pipes. if I can get say 200 litres a minute, I should get an air change every 20 seconds or so.
So I'll try that first.
My one concern is that, when I stuck the vacuum cleaner suction down the air discharge with the door shut, it tripped out.
I'll call Diesel Heat tomorrow.
Thanks again John. You are always a great help.
Keith

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Re: Keith's light weight off roader

Post by Collyn » Sun Jun 09, 2019 4:15 pm

KeithB wrote:
Sun Jun 09, 2019 4:09 pm
Thanks heaps John.
I can't find my original manual and am trying to figure out the little plug-in control panel. The manual you sent is a big help.
Jaycar have a nice little centrifugal blower that will push 1 inch water gauge and will do 740 litres a minute at free flow.
https://www.jaycar.com.au/97mm-x-94mm-1 ... e/p/YX2532
I might make up an adaptor and see what it can push through the one inch pipe, before butchering everything to install bigger pipes. if I can get say 200 litres a minute, I should get an air change every 20 seconds or so.
So I'll try that first.
My one concern is that, when I stuck the vacuum cleaner suction down the air discharge with the door shut, it tripped out.
I'll call Diesel Heat tomorrow.
Thanks again John. You are always a great help.
Keith
The Diesel Heat boss ( I forget his name! used to sell the Webasto product - way back . Give him my regards please - he was very helpful when I was writing about the product.

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Re: Keith's light weight off roader

Post by KeithB » Sun Jun 09, 2019 6:00 pm

Collyn wrote:
Sun Jun 09, 2019 4:15 pm
The Diesel Heat boss ( I forget his name! used to sell the Webasto product - way back . Give him my regards please - he was very helpful when I was writing about the product.
Collyn
Collyn
Graeme Yost sold the business early this year I think. The new owner is Nick Tanner, a very nice bloke too.
Keith

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Re: Keith's light weight off roader

Post by KeithB » Thu Jun 13, 2019 8:09 pm

I've used about 15 litres of diesel trying different combinations to get this heater to work. I put an accurate temperature sensor on it and it runs well up to 52 degrees in the locker and then it trips.

Tried different combinations of fans with no luck. I think the specified maximum ambient temperature for these heaters is 80 degrees. So, talking to Nick at Dieselheat, it looks like it might be a dud CPU. Going we're to try a replacement and see if that does the trick. Nick has been fantastic in his support and perseverance, even though the heater is miles out of warranty. I shudder to think how I'd be with an eBay cheapie.

Mind you, the thing works a treat when it's running. I can see it being toasty in the coldest weather. The idea of ducting warm air from the heater locker in to the composting loo won't solve the problem. But I think it will make the loo compost a lot better. Will look at that after I've got the heater working properly and the thing is registered.

Keith

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Re: Keith's light weight off roader

Post by J.REEVES » Thu Jun 13, 2019 9:54 pm

Hi Keith,
15ltrs, you are giving it a work out!
So you cannot get any codes from the controller as there are a couple for temperature.
Could be a temperature sensor fault maybe the flame temperature sensor.
ECU.JPG
JR
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Re: Keith's light weight off roader

Post by KeithB » Fri Jun 14, 2019 12:00 am

John, I got a hold of the manual for my model from Dieselheat which has all of the error codes. I am consistently getting: "Error 51: Flame sensor check over high temperature during the self-checking time". Gotta love the Chinglish.

Nick at Dieselheat tells me that he's only seen this problem once before and it was fixed with a new CPU. So he's lending me one, complete with a wiring harness, to try out. Changing the flame sensor means it will have to go back to Tassie for surgery.

Nick has been a bit of a Godsend on this one. I've been tearing out what little hair I have left. It's funny that the three biggest problems that I have had on this build are from things that I have bought that haven't worked as advertised: the fridge (two trips to the factory); the slides (the less said the better) and now the heater (15 litres later).

The rear seals are almost complete, the hold down catches are almost on and the wiring for the pop top roof is well on its way. I look like getting the aircon man around next week and we're off to order a mattress and select fabrics on Monday. I bought the bathroom fittings today. Still waiting on my old mate to come around and measure up for the drawers. Only 45 jobs left!

Keith

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Re: Keith's light weight off roader

Post by Collyn » Fri Jun 14, 2019 9:24 am

Keith

You may wish to have some thought about the tyres.

Tyres oxidise constantly. This is normally 'pumped out' in the course of driving (but it still advisable to renew after seven-ten years anyway). If not used, however, that oxidisation seriously hardens and weakens the tyres.

This became known more widely around 2005 or so when two CMCA members had blowouts on tyres on a big MAN and an ACCO that had been built over a course of many years, Both were on their way to a CMCA Rally and the tyres blew out after only a short distance on both vehicles. I too had a similar experience with a 1971 Haflinger that has been unused for ten years.

Tyre companies now warn of this. https://rubberchemtechnol.org/doi/abs/10.5254/1.3548213

It can be avoided by using nitrogen instead of air (if not using the tyre for long periods).
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Re: Keith's light weight off roader

Post by KeithB » Fri Jun 14, 2019 9:51 am

Thanks Collyn.

I haven't bought any tyres yet and will use the two spares off the tug in the first instance to make sure they fit okay. There's not enough headroom in the garage to get any tyres on till it's out in the street. I take your point though and often find myself wondering whether tyres sitting on the back of vehicles out in the Aussie sun are wasting away faster than the ones under the guards.
I like to use one of those cheap digital thermometers to check tyre and bearing temperatures on a trip. It's funny how the ones on the sunny side of the car always get seem to about five degrees hotter.

Keith

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Re: Keith's light weight off roader

Post by Collyn » Fri Jun 14, 2019 1:09 pm

What size are they to be?

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Re: Keith's light weight off roader

Post by J.REEVES » Fri Jun 14, 2019 3:30 pm

Keith,
Changing the CPU is worth a go and it would be good to have a spare if this is not the problem.

As you mentioned earlier the heater works OK with the door open so really sounds like an overheating issue.

From the manual: In the case of overheating (for example, lack of water, poorly vented coolant circuit), the overheating sensor is triggered, the fuel supply is interrupted and the heater turns OFF. Once the overheating has been eliminated, the heater can be restarted manually by turning OFF and ON again.
I really think you have an overheating problem maybe even the CPU has its own high temperature protection.

Possibly the cubical area is just too restricted to allow good air circulation and something is getting to hot. The air you have going into the compartment is enough for combustion but you may need to try and get better air circulation to stop overheating. Possibly attach a temperature probe on the CPU with the door closed and see what temperature you get and then try other locations if that is OK.

Good luck hope the new CPU fixes the problem.

JR
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Re: Keith's light weight off roader

Post by KeithB » Fri Jun 14, 2019 6:10 pm

Collyn, I'll match the tyres on the caravan to what's on the tug - BFG KO2 285 x 33 inch LT. They will handle the GVM, which will be at least 1,000Kg over the tare. The 200 Series mag wheels are the limitation on GVM as I think they are rated at just 2500kg a pair. There is no stamping on them indicating maximum load. I think the GVM will be about 2,850 or maybe a little less. Without any reason for believing so, I think about two thirds GVM is suitable for off road work. But I'd welcome your opinion on that.

Thanks John. The CPU is supposed to be able to run at 80 degrees. But we'll see if a new one fixes it. However, I will take the combustion air from outside. I think it was a bit dumb to to what I have done with the combustion air intake. Will also, per your suggestion, ditch the drinking straws. I have put my workshop vacuum on the outlet air vent and it made no difference to the tripping problem. Nor did a blower on the other side. The other thing I can do later is to move the muffler outside and glass tape the exhaust pipe inside to keep the heat down. I will also duct some of the hot air into the toilet, once the intake is outside. At least that will keep the dunny seat warm.

Keith

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Re: Keith's light weight off roader

Post by Collyn » Sat Jun 15, 2019 10:17 am

Keith - that size seems just fine.

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Re: Keith's light weight off roader

Post by KeithB » Sat Jun 15, 2019 10:52 am

Collyn wrote:
Sat Jun 15, 2019 10:17 am
Keith - are you sure the (tyre) size you have in mind are adequate?
Collyn
Collyn the BFG tyre tables indicate a maximum load of 1450 Kg per tyre at 80 psi for the same tyres that are on the tow. I'll probably run them at less than that as I think (or hope) my loaded weight with full 400 litre water tanks will be about two tonnes - with possibly 150kg on the draw bar.
Perhaps use the 4psi rule and keep and eye on their temperatures to get the right pressure at full load.
I have taken your advice to heart and am planning to run the rear tyres on the tow at higher pressures when towing and am harbouring a forlorn hope that someone in the family will buy me a TPMS for Christmas.
Keith

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Re: Keith's light weight off roader

Post by Collyn » Sat Jun 15, 2019 11:08 am

Keith

Many owners do not understand that the tow vehicle's tyre pressures are one of the most vital factors in assuring caravan towing.

It is essential that the front tyres must never have pressure increased (and can usefully be reduced by 2-3 psi). The rear tyres must be 7-10 psi above the non-towing pressure.

This is even more important if using a WDH. The reason is that the WDH reduces the tow vehicle rear tyre loading (thus reducing their 'cornering power') but cannot reduce the yaw (sway) forces - now imposed on the tow vehicle's rear tyres less able to resist them. Raising their pressures, however, partially compensates - but not totally.

There are of course many other factors of which excess speed is way up the list.

Re tow ball mass - this is less critical with centre-heavy short caravans. What is the overall length?

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Re: Keith's light weight off roader

Post by KeithB » Sat Jun 15, 2019 1:08 pm

Collyn, the main body is 4.2 metres. The extended drawbar will be about 1300mm long and houses the equipment locker which contains about 45kg of gear, with two 4.5 kg gas bottles on top plus there are two 10 litre diesel tanks on the front of the van.
The axle is set about 650 back from the centre to allow for the gate, aircon and spare tyre on the back as well as the BBQ and batteries being very slightly aft by about 700mm. The slideout sleeper is mostly aft of the axle as well. The water tanks have about a 400mm forward bias to the axle. The galley and fridge are both forward of the axle. On my sums, there's almost an even weight split between the wheels.
I think it should tow okay, but I have sacrificed ramp-over angle a bit but putting the axle well back. The departure angle is the same as the tow.
Keith

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Re: Keith's light weight off roader

Post by Collyn » Sat Jun 15, 2019 2:39 pm

Keith
In my opinion, anywhere from 5%-10% tow ball mass should be just fine for towing your laden trailer at up to 110 km/h. It should be rock steady and only barely affected by passing trucks etc. If only more were like this!

The local industry seems to be going barking mad - producing some product that barely a new tow vehicle can handle. It can only get worse as vehicle makers attempt further to reduce emissions by making lighter products. One example as the 2015 or so reduction (with utes) from 3.5 mm to 3 mm for chassis rails.

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Re: Keith's light weight off roader

Post by KeithB » Sat Jun 15, 2019 3:30 pm

Collyn I seem to recall that, in the old days, the laden weight of the trailer could not be greater than the unladen weight of the vehicle. That was good rule, which seems to have gone out the window. And I don't believe the towing ratings quoted for most new vehicles.
So it looks like we're going to be seeing more bent and busted chassis.
Keith

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Re: Keith's light weight off roader

Post by Collyn » Sun Jun 16, 2019 10:05 am

KeithB wrote:
Sat Jun 15, 2019 3:30 pm
Collyn I seem to recall that, in the old days, the laden weight of the trailer could not be greater than the unladen weight of the vehicle. That was good rule, which seems to have gone out the window. And I don't believe the towing ratings quoted for most new vehicles.
So it looks like we're going to be seeing more bent and busted chassis.
Keith

Keith

The explanation is that tow rating use is based on criteria other than towing a pig trailer via an overhung hitch. It assumes a fully laden vehicle's ability to stop and restart on a given gradient, its mechanical ability to withstand such stresses etc. In essence, it is what that full laden vehicle can pull on the end of a rope. Some caravaneers seem unaware that by far the largest use of 4WDs is military and that of dual cab utes is ditto, plus tradies towing short trailers.

The main issue in this area (of overhung hitches) is not so much the weight of the trailer but its length and where weight is distributed.

The major year-long survey now being undertaken at ANU may show up such issues. I was involved in having ANU undertake this (and they have my published work on vehicle stability in this area).

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Re: Keith's light weight off roader

Post by KeithB » Mon Jun 24, 2019 5:19 pm

Got the aircon running today. On low setting and in "Silent" mode is is very quiet and, in this cold Sydney weather, was putting out a lot of heat. It was drawing 48 amps via the inverter when the compressor kicked in, which is pretty much what I expected. I'm guessing an average draw of 25-30 amps when used sensibly. So it should be okay for tropical nights. We will only use it for heating in caravan parks.

I mentioned to the aircon guys who did the pipework that I was still trying to figure out how to get a little pump organised to get rid of the condensate water from the indoor unit. The bottom like is that the water has to go uphill to clear the bead head. They steered me to a local supplier that has a range or pumps designed for the purpose and which clip in under the wall unit and connect to the aircon's power. I put one in, tested it with a load a water in the little reservoir and it worked a treat. It's rated at 14 litres an hour. I'll figure out a way to cover up the pipes and post some more pictures soon.

Keith

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