Aluminum framing for flatbed truck camper

[Logi]

I’m looking at building a flatbed truck camper similar to fwc fleet. Wondering if people have done this before and what size aluminum they would recommend for frame as well as design for frame. Thanks

 

[Kolockum]

FWC and ATCs are made mainly using .125 thick 1x1 tube. A few spots have 1x3 or 1x4 and a thicker C-Channel for the front cab over. Google FWC frames and you will find lots of good examples. There are also several threads of people building their own.

 

[Logi]

Thanks for the info. I had just seen mixed information on other threads saying that fwc uses 1x1 .040 6063-T5 or something smaller than .125 thick. And curious what threads are the ones of people building campers? I have only found a couple of people building aluminum ones. Thanks

 

[Kolockum]

I have only seen a few threads here but there are a lot more over on expeditionportal.com. Although they have a tenancy to overthink everything.

Here is on on WTW that just got started. https://www.wanderthewest.com/forum/topic/21096-m1009-cucv-camper-build/

 

[Logi]

Gotcha thanks

 

[lmwilco1]

I did some frame modifications to my 2019 Grandby and the aluminum tube is much thinner than 1/8 inch.

Louis

 

[ntsqd]

I have been pondering a camper build myself, so I've been thinking about these sorts of considerations. I have a couple issues with using aluminum for a camper frame, and neither has anything to do with welding that metal.

First is that it is a very good thermal conductor. If you use 1" tube and you make the walls ~1" thick (plus the inner & outer skins) then you've just built-in some excellent hot/cold paths.

Second is weight vs. cost vs. strength. I did this analysis on a small trailer and using aluminum didn't pay off. By the time the tube were big enough or thick enough for the anticipated loads there was no weight advantage. And those tubes would have cost almost 3 times what the steel tubes (that were smaller) would have cost. I would definitely have a look at this before committing to using aluminum. Given the normal constraints placed on the design of a camper it could easily be that using steel saves money and weighs the same or less.

My own thought process has taken me in the direction of build a camper using cold molding boat construction techniques. I'm not sure yet just how adaptable those techniques are to constructions with square corners, but I'm still researching and learning. If this is feasible then the camper shell could be every bit as strong as one with a metal frame, will likely be more rigid than a metal frame, and quite probably will end up being lighter. Though my chief reason for all wood construction is thermal insulation and a complete lack of hot/cold paths.

 

[Wandering Sagebrush]

I have been pondering a camper build myself...

<snip>

My own thought process has taken me in the direction of build a camper using cold molding boat construction techniques. I'm not sure yet just how adaptable those techniques are to constructions with square corners, but I'm still researching and learning. If this is feasible then the camper shell could be every bit as strong as one with a metal frame, will likely be more rigid than a metal frame, and quite probably will end up being lighter. Though my chief reason for all wood construction is thermal insulation and a complete lack of hot/cold paths.

There are a number of good boat building books on cold molded techniques that might help you make a decision. One that would be a good starter is the Goegeon Brothers Book on Boat Building. The link will take you to a PDF version.

With power boats, the most obvious sharp corner is where the transom connects, and that is usually a solid piece of wood. I believe a cold molded pop up from wood is very doable, but it’s also going to be very labor intensive.

Interesting...

 

[ntsqd]

Yep, have that pdf, but have not yet had time to study it in depth. I don't think that I would build it exactly as a cold molded boat. For instance the sides and top would be whole sheets rather than strips of okume ply or similar. However I do envision the roof having somewhere about a 200" or larger radius to it rather than being flat. Still, those thin sheets shouldn't have any trouble bending to conform to a radius that large. The other, likely obvious deviation would be some form of insulation between the ribs of the entire shell. (An insulated & radiant heated floor might be nice......)

Since a camper is fairly rectilinear (particularly as compared to a boat) I suspect that the amount of labor involved will be less than a boat of similar volume. That isn't to say that the labor time investment will be puny, just that I'd expect it to take a lot less time than a boat would. I do need to wrap up the 1/2 dozen or so on-going large projects that I'm currently working on before I can even consider building a camper.

The other consideration is the tools required. I'm estimating that alone would be a $2k-$3k expense on top of the limited wood working tools that I already have.

 

[Wandering Sagebrush]

Thom, my philosophy on tools. Use it one time, it’s paid for itself.

 

[WillTheThri11]

My 90s Ranger II is made primarily of .040-.050 1" square tubing. The cabover part is thicker I believe but probably not.125" I did a repair using 1/16" 6061-T6 and I can tell you that it's way stiffer and more stout than the original framing. I wasn't able to locate "original-style" rounded corner tubing at all actually and that .040" thick stuff is a real pain to weld if you're not a pro. I think if you used 1/16" thick tubing you'd have a very strong camper.

 

[Kolockum]

I went out and measured the tubing in my camper and it is .050. Not sure where I got the .125.

 

[zuber]

+1 on the use of steel. Strength is not usually the design issue, it is deflection. Steel is rigid, aluminum is like a spring. Steel is very easy to weld, alum not as easy. Aluminum is also much more prone to crack. Steel is significantly cheaper to buy also.

 

[Avg.Joe]

It's been a few months since the op started this. Still considering the project? If so I can share info on our all wood camper (built last year) and a boat builders perspective on the project.

 

[ntsqd]

If no one else is, I'm interested in your all wood camper. I seem to recall that you have a build thread here. I'll have to find it.

 

[Avg.Joe]

If no one else is, I'm interested in your all wood camper. I seem to recall that you have a build thread here. I'll have to find it.

Diy home build is what I called the thread...or something close to that.

A good friend who's been building boats and planes for years gave me the courage I needed to do the project. With no experience, I used a lot of wood. Probably way more than is needed. The pop up has four 90# struts and still takes effort.

I keep saying next time I'll do this and that different but I really should be hoping to use this one for a good long time. I'm curious how the move to electric vehicles is going to affect us truck camper users and so I think about ways to build the bed and camper lighter to eventually fit an electric platform. I don't know, maybe the next one will be a pop top van.

Along the lines of this thread though, I've seen folks do a real nice job with thin gauge steel for truck beds. For me, that would be easier to fab and likely less expensive. My factory built aluminum bed is heavy as heck but built to haul a huge amount. With a truck camper like the ones we're talking about here, the beds don't need to be so dang heavy.