OBXcamper wrote:
If your plywood works out it would really look good to clearcoat and let the wood grain show.
If your plywood works out it would really look good to clearcoat and let the wood grain show.
We actually plan on two layers of the 5mm, cold molded with west system epoxy inbetween. Hopefully this will make a pretty solid but not too heavy roof that you can walk on.
Unsure if the exposed mahagony roof with painted aluminum sides on the camper would look a bit redneck homemade vs using something like TPO, EPDM or aluminum skin on the roof over the mahagony.
69 Avion wrote:
Some of the military trucks use a spring mount that allows the frame to flex more than the flat bed. An example would be the older 2-1/2 ton trucks. The bed is seperated from the frame with wood and the front bed mount has springs.
Some of the military trucks use a spring mount that allows the frame to flex more than the flat bed. An example would be the older 2-1/2 ton trucks. The bed is seperated from the frame with wood and the front bed mount has springs.
Trying to remember what my WWII 2-1/2 ton had. Don't recall it having spring mounts at the front, but it would make sense (I admit I never crawled under the spare wheel mount to see how the bed was attached).
Jfet wrote:
...The 20 foot steel flatbed is quite thick and rigid and is u-bolted in many places to the frame. I drove a tire on a curb and the frame/flatbed seem to stay as one unit, meaning there may not be issues with twisting being transfered to the camper frame (except the cab/camper overhang clearance issue, which I have given almost 5 inches allowance).
So all of that said, I am thinking of using your typical camper tiedown devices directly to the flatbed.
edit: After looking at the link you posted, I also see that they were refering to mostly wood frame glue and screw campers. I do wonder if my fully welded tubular steel frame might hold up a bit better to flex...
...The 20 foot steel flatbed is quite thick and rigid and is u-bolted in many places to the frame. I drove a tire on a curb and the frame/flatbed seem to stay as one unit, meaning there may not be issues with twisting being transfered to the camper frame (except the cab/camper overhang clearance issue, which I have given almost 5 inches allowance).
So all of that said, I am thinking of using your typical camper tiedown devices directly to the flatbed.
edit: After looking at the link you posted, I also see that they were refering to mostly wood frame glue and screw campers. I do wonder if my fully welded tubular steel frame might hold up a bit better to flex...
The loadbed and frame staying as one unit when a wheel is lifted may simply mean that both are twisting slightly together - i.e. the flatbed is twisting and that twisting would be transferred to anything rigidly bolted to it. I used to be involved in heavy vehicle trialling years ago (tanks, 6x6 army trucks, etc.) and noticed how much the load beds of these big flatbed trucks twisted when offroad. OK, that's an extreme example, but worth considering.
Hence I think you are right to go with regular TC tiedowns - specifically spring-mounted so they allow a corner of the camper to lift if needed. If it were rigidly bolted to the bed then I would worry about the very rigid camper trying to resist the entire bending force of the frame causing cracking in the camper's welds - in a way the more rigid it is the more vulnerable as it won't flex with the load bed / frame but will try to resist it.
I also wonder if some sort of rubber matting between the camper and the load bed might be an advantage too to absorb vibration.
Steve.
'07 Ford Ranger XLT Supercab diesel + '91 Shadow Cruiser - Sky Cruiser 1
'98 Jeep TJ 4.0
'15 Ford Fiesta ST
'09 Fiat Panda 1.2
OBXcamper wrote:
If your plywood works out it would really look good to clearcoat and let the wood grain show.
If your plywood works out it would really look good to clearcoat and let the wood grain show.
x2 - that would look fantastic.
Steve.
I think Steve is pretty much spot-on regarding twist. The heavier the load and the more likely twist will happen. I got to arguing about this alittle bit with a guy on another forum and he took me up on my suggested challenge and drove one wheel up on a block or something and he showed pics that looked pretty clear it wasn't twisting at all. I kind of gave up on the argument but he had a tiny camper on an F550 and over time I have become convinced that was the reason. The frame on my Kodiak is way stiffer than the F550, yet mine twists a lot over uneven ground. The difference is I am carrying about 19,000 GVW of which maybe 8K is the bed and camper.
I should grab a picture of my Kodiak shop manual (or is it the body builder's guide?) because it actually has the recommended design for super inflexible loads such as a water tank. The more inflexible the load, the more you might need a flexible mount. The design actually strikes me as simpler than many complicated setups I have seen such as on the expo forum, but basically a strong spring between tabs on the frame and bed in the front and solid mounts at the back. You might check the body building guide for your chassis if there is one.
The original builder of my rig actually set the camper in the bed on some sheets of plywood (the cab is extra tall so it had to be lifted) and then used a forklift to lift one front wheel....observed the amount of flex and then added or subtracted enough sheets to have the proper clearance. Then he mounted it using normal spring loaded turnbuckles from Happijac. I switched them out with Fastguns quickly. But he thought the steel flatbed already flexed some, and there was no need to do a special bed mount. It was flexible enough to help drive on rough roads, but not so flexible he worried about the camper holding up. In the end the simple solution worked for him on a 1-year trip to South America and back, and us for another 5 years of camping for a total of about 2 straight years of camping full-time and the Lance has held up nicely. Your structure will more rigid than the Lance which could be a good or bad thing depending on how everything works together. I think it is probably wise to plan on not doing anything special to begin with, but closely monitor the tie downs to begin with and make a change if necessary later.
Great looking project - I am jealous; I'd love to do that someday.
Quote:
Perhaps TPO or that other EPDM
Perhaps TPO or that other EPDM
TPO loves full sun; it thrives under it. However, since you are considering a barrier material as a sandwich/vapor barrier hdden from the direct incoming solar, you may want to consider EPDM as that layer.
Before proceeding, contact the EPDM applications engineering people at the manufacturer, and run the idea by them first (i.e. the best adhesive, compression & shear {the EPDM will act as as a rubber shock pas of sorts}, etc...) and the temperature environment (the EPDM will be operating n a potentially extremely high heat environment)...
Cheers,
S-
Silver
2004 Chevy Silverado 2500HD 4x4 6.0L Ext/LB Tow Package 4L80E Michelin AT2s| Outfitter Caribou
Most of the time, we just threw a U-bolt around the frame rails / wood spacer and the bottom rail on the body or bed.
As for hauling on large objects, I owned a 4 truck fleet that was hired on to a carrier as part of their heavy haul division. When we hauled Dromedary boxes (basically like having a camper on a flatbed), we had to cross chain side to side and front to rear. I can remember having to take those drop deck trailers being put through some real torsional stress, when delivering the "Droms" to some site that required being off-road. Of course, "Drom" boxes are a little tougher than a camper, but we never used any type of springs or suspensions. As a matter of fact, the worst things to haul were vehicles with suspensions on our drop deck trailers, lo-boy trailers or even flat bed trailers. Even though we also cross chained the vehicles, they would bounce and flex on their own, which caused the chains to loosen and we would have to go back and tighten them.
I believe that if the structure is built secure enough, and mounted to the bed, you should be golden. At this stage of the build, you might want to think about having two rails under the camper and mount it to the chassis similar to the way that commercial bodies are mounted. ... Just a thought.
ON EDIT:
I just happened to find this video on another thread. At about the 13 minute mark, you will see that they have their camper bolted directly to the truck bed. I also like their jacking system.
Aussie Camper
* This post was edited 03/13/13 03:44pm by Photog101 *
Biggest thing I like is keeping part of the bed in the main area with putting the cabinets under for extra storage. I'll be curious to see the end results.
When you are figuring where things go, don't forget to think about how to repair something. Even things like grey tanks may break after time or in mishaps. While removing a shower stall may be acceptable to replace a grey tank, it would be terrrible to have to rebuild walls in the process.
For the aluminum roof, there needs to be a barrier between the plywood and metal. There tends to be a reaction to between the two and may cause pitting at the contact point. They make a carboard type material for this purpose.
Nice to hear the DW is doing the drafting making this a true team effort. Would love to see some of her drawings.
2015 Ram 3500 4x4 Crew Cab SRW 6.4 Hemi LB 3.73 (12.4 hand calc avg mpg after 92,000 miles with camper)
2004 Lance 815 (prev: 2004 FW 35'; 1994 TT 30'; Tents)
sabconsulting wrote:
Trying to remember what my WWII 2-1/2 ton had. Don't recall it having spring mounts at the front, but it would make sense (I admit I never crawled under the spare wheel mount to see how the bed was attached).
The loadbed and frame staying as one unit when a wheel is lifted may simply mean that both are twisting slightly together - i.e. the flatbed is twisting and that twisting would be transferred to anything rigidly bolted to it. I used to be involved in heavy vehicle trialling years ago (tanks, 6x6 army trucks, etc.) and noticed how much the load beds of these big flatbed trucks twisted when offroad. OK, that's an extreme example, but worth considering.
Hence I think you are right to go with regular TC tiedowns - specifically spring-mounted so they allow a corner of the camper to lift if needed. If it were rigidly bolted to the bed then I would worry about the very rigid camper trying to resist the entire bending force of the frame causing cracking in the camper's welds - in a way the more rigid it is the more vulnerable as it won't flex with the load bed / frame but will try to resist it.
I also wonder if some sort of rubber matting between the camper and the load bed might be an advantage too to absorb vibration.
Steve.
69 Avion wrote:
Some of the military trucks use a spring mount that allows the frame to flex more than the flat bed. An example would be the older 2-1/2 ton trucks. The bed is seperated from the frame with wood and the front bed mount has springs.
Some of the military trucks use a spring mount that allows the frame to flex more than the flat bed. An example would be the older 2-1/2 ton trucks. The bed is seperated from the frame with wood and the front bed mount has springs.
Trying to remember what my WWII 2-1/2 ton had. Don't recall it having spring mounts at the front, but it would make sense (I admit I never crawled under the spare wheel mount to see how the bed was attached).
Jfet wrote:
...The 20 foot steel flatbed is quite thick and rigid and is u-bolted in many places to the frame. I drove a tire on a curb and the frame/flatbed seem to stay as one unit, meaning there may not be issues with twisting being transfered to the camper frame (except the cab/camper overhang clearance issue, which I have given almost 5 inches allowance).
So all of that said, I am thinking of using your typical camper tiedown devices directly to the flatbed.
edit: After looking at the link you posted, I also see that they were refering to mostly wood frame glue and screw campers. I do wonder if my fully welded tubular steel frame might hold up a bit better to flex...
...The 20 foot steel flatbed is quite thick and rigid and is u-bolted in many places to the frame. I drove a tire on a curb and the frame/flatbed seem to stay as one unit, meaning there may not be issues with twisting being transfered to the camper frame (except the cab/camper overhang clearance issue, which I have given almost 5 inches allowance).
So all of that said, I am thinking of using your typical camper tiedown devices directly to the flatbed.
edit: After looking at the link you posted, I also see that they were refering to mostly wood frame glue and screw campers. I do wonder if my fully welded tubular steel frame might hold up a bit better to flex...
The loadbed and frame staying as one unit when a wheel is lifted may simply mean that both are twisting slightly together - i.e. the flatbed is twisting and that twisting would be transferred to anything rigidly bolted to it. I used to be involved in heavy vehicle trialling years ago (tanks, 6x6 army trucks, etc.) and noticed how much the load beds of these big flatbed trucks twisted when offroad. OK, that's an extreme example, but worth considering.
Hence I think you are right to go with regular TC tiedowns - specifically spring-mounted so they allow a corner of the camper to lift if needed. If it were rigidly bolted to the bed then I would worry about the very rigid camper trying to resist the entire bending force of the frame causing cracking in the camper's welds - in a way the more rigid it is the more vulnerable as it won't flex with the load bed / frame but will try to resist it.
I also wonder if some sort of rubber matting between the camper and the load bed might be an advantage too to absorb vibration.
Steve.
I had two in my backyard, but I'm down to only one now. It is a 1975 AM General with about 12,000 miles on it. I have taken the beds off before so I remember the springs on them. I imagine that the reason the 2-1/2 ton trucks have them and "on the road" trucks don't have them is because of the rough use the military truck get put through.
Ford F-350 4x4 Diesel
1988 Avion Triple Axle Trailer
1969 Avion C-11 Camper
Re: the frame twist, a few years ago I was working on a military vehicle project and on those with boxes on the back, ie, "campers" they used a special 3 point pivoting mount system that isolated the box from the frame. It was designed such that a moment could not be transmitted from the frame to the box.
Do some searches and I'm sure you can find some info/pics of similar mounts.
Dan
Right now I am getting closer to needing to come up with the skin design for the roof. If I use aluminum and need something to go between the aluminum and marine plywood, how do I attach the aluminum to the plywood without using fasteners? It would be a shame to have a true one piece aluminum roof with zero holes, then mess it all up with leaky rivits.
Further, how hard is it going to be to obtain and manuever 8.5 feet by 22 feet of 0.050 aluminum...
Perhaps the other ideas, like EPDM or fiberglassing the plywood...