More design ideas/questions

[Mickldo]

While I was doing all that driving up to the 'Curry and back I had a couple of thoughts on my camper.

I want to chop the 105 into dual cab and extend the chassis to give me enough room for the camper shell. Normally you extend the wheelbase too so you get the front and rear axle weights right. The other way is to add a lazy axle or do a six wheel drive conversion. I am not a fan of lazy axles but there aren't too many good 6x6 conversions out there.

As a bit of a thought continuation from my boat thread I came up with the idea of running the forward rear axle as per OEM specs and have the add-on rear axle driven by an electric motor to make a hybrid. You could drive it as per normal and just have the rear as a lazy axle, just have the rear driving with the electric as a RWD configuration or you could have the whole six driven by a mixture of drivetrain and electric. Being ABS the 105 already has wheel speed sensors which may or may not help rig it all up.

What do you all reckon? Am I dreaming again (or still??)?

Worst comes to worse I can just disable the electrics and just have a lazy rear axle. The 105's have fully floating axles so the motors wouldn't be an integral part of the wheel assemblies.

Of course you would need a lot of batteries to run the electric motors but adding the extra axle adds an extra ton to the GVM available.

Here's a link to Hino's new hybrid truck http://www.hino.com.au/models_hybrid_landing.aspx?TabID=3 If only they did the hybrid in the 4x4 model http://www.hino.com.au/models_4x4_landing.aspx?TabID=3

 

[Mickldo]

Does anybody have any experience with adding axles?

What special things need doing to the brake circuit (especially as the 105 has ABS)? Do you just tee into the rear circuit or do you have to adjust the brake proportioning too?

If anybody follows the OZ rockcrawling scene they would have heard about Haultech traction control. http://www.haultech.com/Traction.shtml With the extra axle and the ABS sensors already there something like this might be good to integrate to help maintain wheel speed and traction on the electric axle.

 

[Mickldo]

Other ideas I had while I was away.

Keep the camper shell low profile and streamlined - The wind out there really buffeted us around, any extra bits sticking out would have added heaps to the fuel consumption.

Keep the camper as inconspicuous as possible - On my last trip I had my 4" lifted, big tyred HZJ80 and I could tell everybody was staring at me and not in a good way. This trip it was in a stock looking HZJ105 and I just blended right in. Every second car on the road was either a 100 or a 75 series cruiser. Even by chopping the back I could still try to blend in, there were a lot of mines vehicles out there and a lot of other work vehicles. Some of these were chopped wagons with canopies so I want to try and keep it looking like a work vehicle rather than a RV. At least externally anyway.

Extra lighting - Even though the 105 has good stock headlights and I have a good set of Hella 4000's when you are out west there and doing any traveling at night then you need good lights. I am thinking of integrating in some roof mounted spotlights into the leading edge of the camper shell, maybe behind a perspex wind deflector or something. Either that or I look at HID lighting a bit more.

 

[Mickldo]

Here are a couple of photos I took with my camera phone the other day of an F250 camper. Please excuse the quality of the photos as I was driving at the time (shh, don't tell anybody).





You can sort of see a window or something above the cab. I was thinking something like that for hiding the spotlights behind.

 

[Mickldo]

A couple of photos of some gullwing canopies we have made at work. For mine I will use a different construction technique but the shape and profile will be similar.









Note the complex water tracks on the door seals. We have used this design on hundreds of boxes we have built for the electricity company and we have had no reports back of water leakage or dust leakage.

This is still the canopy design I want to use. I will try to incorporate a pop top of some sort to give extra headroom and to have the slide out modules the size of the side door openings. There would be a passenger access door at the rear in the centre.

I have acquired the use of a design program from my brother so I am hoping to have some drawings soon.

 

[ntsqd]

Lighter force versions of those gas springs used on the service body doors can also be used to move an articulated light bar. Lay them flat (lower aero profile) and latch them there for day time travel. Pop the latch and allow the springs to push the light bar up into position for night use.
The bonus of the design is that any branch or low hanging object will simply fold the light bar back and once clear of the obstruction the springs will return it to position.

I blatantly stole this idea from BCG1 of the LocosMocos and have used it on one of our desert race trucks. In this application the 'hinge' is typically a spherical rod end bearing at each end of the light bar.

The problem that I see with any sort of plexiglas/lexan/etc. 'window' in front of high power lights is distortion of the beam(s) and glare into whatever might be behind the lights.

 

[Mickldo]

Lighter force versions of those gas springs used on the service body doors can also be used to move an articulated light bar. Lay them flat (lower aero profile) and latch them there for day time travel. Pop the latch and allow the springs to push the light bar up into position for night use.
The bonus of the design is that any branch or low hanging object will simply fold the light bar back and once clear of the obstruction the springs will return it to position.

I blatantly stole this idea from BCG1 of the LocosMocos and have used it on one of our desert race trucks. In this application the 'hinge' is typically a spherical rod end bearing at each end of the light bar.

The problem that I see with any sort of plexiglas/lexan/etc. 'window' in front of high power lights is distortion of the beam(s) and glare into whatever might be behind the lights.

They use a similar setup on the Outback Challenge rigs. They use an electric motor or a pneumatic ram to tilt them up and down. Instead of turning the lights on and off if they want to dip their headlights they just hinge them back. This works well with the HID lights they use as they don't have to wait for them to heat up again. They look freaky with the lights shining straight up into the air when you pass them.

My problem is I won't have any room to tilt them out of the way. I have been thinking of having the camper sit up a bit above the cab any way to give me extra room in the camper.

My Hella 4000's have some clear covers that I leave on all the time. If I was to do this idea I'd keep the perspex vertical to limit any distortion.

edit; I just remembered I was thinking of mounting my spare wheels on the roof of the cab. Maybe I'll have to mount the lights in front of the spares instead of on the leading edge of the camper. Or mount the spares somewhere else.

 

[Bogo]

After my trip to Cloncurry, where the temp didn't go under 40 degrees C the whole trip, I now realize that I need to work more on insulation and cooling. Even though the windows are tinted and I had them cracked a little bit for ventilation the temp on the fridge thermometer was around 50 degrees C for the ambient temp. We had the plastic bag on the loaf of bread melt to the crust. The wife had a bag of Chico Babies that melted into one molten mass of candy. Who knows what else was damaged by the heat.

I think my idea of a filtered ventilation to the cabin will work but I think I will need better insulation than what I had planned.

On insulation: Spray in foam is one way to go. I have no clue what is available down under, but I can get R-7.4 easily here in the states in a 2 part canister pair.

Another thing to think of is radiant heat gain. Sol can be brutal. If you have a reflective foil layer just under your outside skin it will do wonders for keeping the worst of the heat gain at bay. Remember that heat will radiate up from the ground too, not just Sol in the sky. The trick is it needs to be separated from the outside skin by an air gap. That gap can be maintained by a netting sandwiched in between. I haven't done this and haven't heard of it being done yet: I was thinking of using a high temperature adhesive to glue the netting to the inside of the outside skin. Then I'd glue the foil on to the netting. Actually if you soak the netting in adhesive it will glue to the skin and then the foil can be applied to the inside. Finally I'd spray the foam in after the adhesive has setup. The idea needs some testing to see if it will hold up to abuse and to see if the foil gets pressed against the outside skin by the foam. The adhesive needs to handle 250F without loss of strength. Tough to find. Second Skin Audio seams to have found it for applying their sound deadening mats. I just haven't been able to get thier site to load tonight.

More on reflective layers: TekFoil is a bubble wrap like insulation product. It basically is a layer or two of bubble wrap with reflective foil faces. Bubble wrap insulation it's self isn't all that good at night, but it is better than nothing and it is very light. I would look at the foil/bubble/poly versions for use in AU. The poly face when put to the inside won't reflect interior heat back in. The Handi-Foam spray in foam this place also handles is only R-4 per inch. There is much better out there.

For the ultimate in reflective use gold foil. Gold is the best at reflecting IR radiation. The kicker is now your rig looks like a million bucks...

On cooling... In the past few years a good number of 12VDC and 24VDC powered air conditioners have hit the market. They are being mainly sold to the trucking industry as they are more efficient than engine driven ones and with a big battery bank you can run them overnight without running the engine. That means big diesel savings when truckers are sleeping in the cab. One company was saying it only took a 24VDC 220AH battery bank for 50% duty cycle for 8 hours. To a trucker that is 2 8D batteries which is a common truck battery size. Recharge is done while the truck is driving during the day. Autoclima seams to sell generic units to cool buses, RVs, etc. They are Italian. There are other manufacturers out there. Oh, the other reason they are being put into trucks. Efficiency. An engine driven compressor wastes allot of energy. The DC powered ones only run when they are needed and thus can save as much as 5% on fuel use on top of the over night fuel savings. Fleet managers eyes light up when they see savings numbers like that. I've thought of ripping out the engine driven compressor and replacing it with a 24VDC alternator. It would charge a 24VDC battery bank and supply power for a 24VDC air conditioning unit as well as other electrical loads. If done with the same voltage as the primary alternator it provides redundancy for the alternator. If the battery bank is made of 3 or more batteries it can be pulled out and reconfigured in series for emergency welding. Even if you don't have enough battery capacity for running A/C over night consider having three or more batteries so you can do welding. Consider using 3 35AH batteries in parallel instead of one 100AH battery.

 

[Mickldo]

On insulation: Spray in foam is one way to go. I have no clue what is available down under, but I can get R-7.4 easily here in the states in a 2 part canister pair.

Another thing to think of is radiant heat gain. Sol can be brutal. If you have a reflective foil layer just under your outside skin it will do wonders for keeping the worst of the heat gain at bay. Remember that heat will radiate up from the ground too, not just Sol in the sky. The trick is it needs to be separated from the outside skin by an air gap. That gap can be maintained by a netting sandwiched in between. I haven't done this and haven't heard of it being done yet: I was thinking of using a high temperature adhesive to glue the netting to the inside of the outside skin. Then I'd glue the foil on to the netting. Actually if you soak the netting in adhesive it will glue to the skin and then the foil can be applied to the inside. Finally I'd spray the foam in after the adhesive has setup. The idea needs some testing to see if it will hold up to abuse and to see if the foil gets pressed against the outside skin by the foam. The adhesive needs to handle 250F without loss of strength. Tough to find. Second Skin Audio seams to have found it for applying their sound deadening mats. I just haven't been able to get thier site to load tonight.

More on reflective layers: TekFoil is a bubble wrap like insulation product. It basically is a layer or two of bubble wrap with reflective foil faces. Bubble wrap insulation it's self isn't all that good at night, but it is better than nothing and it is very light. I would look at the foil/bubble/poly versions for use in AU. The poly face when put to the inside won't reflect interior heat back in. The Handi-Foam spray in foam this place also handles is only R-4 per inch. There is much better out there.

For the ultimate in reflective use gold foil. Gold is the best at reflecting IR radiation. The kicker is now your rig looks like a million bucks...

On cooling... In the past few years a good number of 12VDC and 24VDC powered air conditioners have hit the market. They are being mainly sold to the trucking industry as they are more efficient than engine driven ones and with a big battery bank you can run them overnight without running the engine. That means big diesel savings when truckers are sleeping in the cab. One company was saying it only took a 24VDC 220AH battery bank for 50% duty cycle for 8 hours. To a trucker that is 2 8D batteries which is a common truck battery size. Recharge is done while the truck is driving during the day. Autoclima seams to sell generic units to cool buses, RVs, etc. They are Italian. There are other manufacturers out there. Oh, the other reason they are being put into trucks. Efficiency. An engine driven compressor wastes allot of energy. The DC powered ones only run when they are needed and thus can save as much as 5% on fuel use on top of the over night fuel savings. Fleet managers eyes light up when they see savings numbers like that. I've thought of ripping out the engine driven compressor and replacing it with a 24VDC alternator. It would charge a 24VDC battery bank and supply power for a 24VDC air conditioning unit as well as other electrical loads. If done with the same voltage as the primary alternator it provides redundancy for the alternator. If the battery bank is made of 3 or more batteries it can be pulled out and reconfigured in series for emergency welding. Even if you don't have enough battery capacity for running A/C over night consider having three or more batteries so you can do welding. Consider using 3 35AH batteries in parallel instead of one 100AH battery.

Hey Bogo

I haven't decided yet on what type of insulation to use yet but I'll have 40mm gap between the inner and outer sheets. I plan on using 40 x 40 ally box section with Di-Bond sheeting (which is a little bit insulative). I will need to run wiring and plumbing behind the sheets but the rest of the space is available for insulation. I am worried about the box section itself though. Being alloy it will conduct heat/cold and it is connected to the inner and outer sheets. I will be using 3M double sided VHB tape which should insulate it a little. What about pouring 2-pack foam down the tubes? Waste of time or would it be worth it?

I have seen the foil coated bubble wrap before and I have seen a couple of other different foams, etc. At work we use Microlen Buoyancy Foam for insulation on our boats. It works pretty well but if there is a better alternative I will use it. There is an engine bay insulation foam we use on our inboard powered boats but it is expensive, it would cost me a couple of grand to do the camper.

I'll have to do a couple of calculations to see if the AC would be worth it but if it works out to be OK I would definitely be interested.

 

[Mickldo]

I also like ntsqd's idea of sleeping bag material for insulation on the pop top. I'd love to have hard sides but I think that an insulated soft top would be heaps easier to make and to get to work properly.

 

[Bogo]

Hey Bogo

I haven't decided yet on what type of insulation to use yet but I'll have 40mm gap between the inner and outer sheets. I plan on using 40 x 40 ally box section with Di-Bond sheeting (which is a little bit insulative). I will need to run wiring and plumbing behind the sheets but the rest of the space is available for insulation. I am worried about the box section itself though. Being alloy it will conduct heat/cold and it is connected to the inner and outer sheets. I will be using 3M double sided VHB tape which should insulate it a little. What about pouring 2-pack foam down the tubes? Waste of time or would it be worth it?

I have seen the foil coated bubble wrap before and I have seen a couple of other different foams, etc. At work we use Microlen Buoyancy Foam for insulation on our boats. It works pretty well but if there is a better alternative I will use it. There is an engine bay insulation foam we use on our inboard powered boats but it is expensive, it would cost me a couple of grand to do the camper.

I'll have to do a couple of calculations to see if the AC would be worth it but if it works out to be OK I would definitely be interested.

The trick will be getting the foam into the tubes. I bet access holes would be needed. It will help some, but I don't know how much. I figured on not filling them. It's only a RV. I figure it would be better to figure out how to break the heat path. This past weekend I talked with an aircraft structural engineer. He suggested going to hat channels rather than using square or round tube. Place the channels back to back where strength is needed and offset or crossed where only stiffness is needed. A thick VHB tape would be used to hold the back to back hat channels together where they meet. Cross joints would need to be spot welded or similar. He also mentioned that you can bend hat channels like tube if you have a set of bending dies made. You do need different dies for inside versus outside bends. The nice thing about hat channels is they can be made from sheet metal with a metal break or formed on a press. I've been looking at hat channels and other shapes to come up with a few simple dies I could use in a 40 ton press to form the internal bracing for the micro RV. An example would be a die to do the internal stiffener at the corner of a door. The long pieces along the edges would be formed on a metal break with couple inches of overlap to tie them together.

Enough with hat channels. The price of DC powered A/C is dropping. When I first saw them a few years back it was $3500US for a semi cab unit. Now it is down to $2000 to $2500. Some day they may reach true affordability. I see no reason they are much more expensive than a 120VAC powered one other than economies of scale. That means they should approach $700 or less. I know I could justify $1000 for a 8000BTU roof top mounted unit. We'll see if I can justify one when it comes time to change my truck's A/C compressor. I fear it's seals only have a few more years life in them.

I thought of this today. Highly reflective auto paint to provide the first radiant heat barrier. A high reflectivity white or silver metallic? How is highly polished aluminum at reflecting heat? Just having the roof white could help allot. Now where have I seen that?

 

[Bogo]

I also like ntsqd's idea of sleeping bag material for insulation on the pop top. I'd love to have hard sides but I think that an insulated soft top would be heaps easier to make and to get to work properly.

At an RV show I saw an insulated pop up where the cloth was two layers of the standard vinyl with a 1/2" thick sleeping bag padding foam bonded between them. There were strategic lines where there wasn't foam so it would fold nicely. They say it better than halved the heating propane use in the winter over a single layer of vinyl for the same pop up camper. Along these lines the foil bubble wrap could be put in between and only bond it at the edges. Some more care in handling would be needed. On reflective layers. I've seen heat reflective ripstop nylon at Seattle Fabrics. That could be incorporated into a more sleeping bag like structure.

 

[Mickldo]

The trick will be getting the foam into the tubes. I bet access holes would be needed. It will help some, but I don't know how much. I figured on not filling them. It's only a RV. I figure it would be better to figure out how to break the heat path. This past weekend I talked with an aircraft structural engineer. He suggested going to hat channels rather than using square or round tube. Place the channels back to back where strength is needed and offset or crossed where only stiffness is needed. A thick VHB tape would be used to hold the back to back hat channels together where they meet. Cross joints would need to be spot welded or similar. He also mentioned that you can bend hat channels like tube if you have a set of bending dies made. You do need different dies for inside versus outside bends. The nice thing about hat channels is they can be made from sheet metal with a metal break or formed on a press. I've been looking at hat channels and other shapes to come up with a few simple dies I could use in a 40 ton press to form the internal bracing for the micro RV. An example would be a die to do the internal stiffener at the corner of a door. The long pieces along the edges would be formed on a metal break with couple inches of overlap to tie them together.

Enough with hat channels. The price of DC powered A/C is dropping. When I first saw them a few years back it was $3500US for a semi cab unit. Now it is down to $2000 to $2500. Some day they may reach true affordability. I see no reason they are much more expensive than a 120VAC powered one other than economies of scale. That means they should approach $700 or less. I know I could justify $1000 for a 8000BTU roof top mounted unit. We'll see if I can justify one when it comes time to change my truck's A/C compressor. I fear it's seals only have a few more years life in them.

I thought of this today. Highly reflective auto paint to provide the first radiant heat barrier. A high reflectivity white or silver metallic? How is highly polished aluminum at reflecting heat? Just having the roof white could help allot. Now where have I seen that?

I am hoping that the Di-Bond with its plastic centre and the VHB tape will provide enough interruption to the heat path. Before I sheet it I could drill holes in the tube to pour the foam in.

We use hat section to make the frames in the racecar trailers we build at work. The hat section we use is an extrusion normally used to frame small pressed aluminium boats or tinnies as they are known here. The hat is 30mm high which I find is a bit small for the wiring and plumbing to fit behind easily, this is why I chose 40mm box. The hat section is a lot more fiddly to make the frame which is another reason I chose the box.

The AC units looked to have Danfoss compressors. I wonder if there was a way to DIY the install. This way I could plumb the ducting to where I want it and to be able to run a Donaldson filter to pre clean the air.

The Di-Bond comes in a range of colours (13 IIRC), among them are silvers and whites. My 105 is a darker grey/silver colour but I reckon that I might just stick to the white for the camper. MMMMmmmmm.........teakettlin........

 

[Mickldo]

At an RV show I saw an insulated pop up where the cloth was two layers of the standard vinyl with a 1/2" thick sleeping bag padding foam bonded between them. There were strategic lines where there wasn't foam so it would fold nicely. They say it better than halved the heating propane use in the winter over a single layer of vinyl for the same pop up camper. Along these lines the foil bubble wrap could be put in between and only bond it at the edges. Some more care in handling would be needed. On reflective layers. I've seen heat reflective ripstop nylon at Seattle Fabrics. That could be incorporated into a more sleeping bag like structure.

I might have chat with our new upholsterer we now use for work. He is building a RTW Catamaran with electric backup motors. He is a Sailmaker so he should know about the different fabrics that are available over here.

 

[Mickldo]

Here's a couple of pics of one of our race car trailers.