Aluminum Frame Camper

[John D]

I think a lightweight camper should have an aluminum frame with good welding. In my opinion, this type of construction is superior to other methods used in lightweight camper construction. Discussion invited. John D

 

[pods8]

What discussion are you trying to kick up? Welded Al definitely is tried/true. I'd suspect riveted Al would also work quite well when done properly. Time will tell on the frameless foam core designs but it's worked well for boats, planes, etc. so no real reason to think it won't. Frameless construction is probably lighter and doesn't have thermal bridging but you need to plan ahead when constructing it for attachment points, etc. and you can't just easily open up a panel to access it later. I'm becoming of the opinion that it is more time consuming than I suspect a traditionally framed/skinned camper would be.

As I daydream on my project I think it I were to build another camper I might consider looking into aluminum framing (perhaps using angles rather than box). But what I think I'd do is cut form fitting foam board to put between the members and glue that in place to the members with a flexible adhesive. Then maybe glue the exterior skins onto the face of the frame/foam. It would provide robust backing for the skins and by tying it all together it should be stronger. The interior could then be traditionally fastened into place which would afford access to run wiring, etc. and also add more attachment points if needed. Just some random, untested thoughts.

 

[ntsqd]

I would say that aluminum may or may not the best for low weight, but is not the best for fatigue life. In which case steel would be the better choice. One project of mine was roughly designed for size and then appropriately sized steel tube sizes vs. appropriately aluminum tube sizes were analyzed for weight and cost. Turned out that the weight difference was very small and the aluminum cost was about 3 times that of the cost for steel. That particular project was not a very big structure so diminishing returns etc., but it is illustrative of there being no fixed answer.

In '96 during the Tour del Sol there was a short range vehicle entered in the gymkhana made almost entirely of clear fir and birch plywood. It was built much like a boat with good, tightly fit joints that were adhered and then had a thin (1-2 layers of woven cloth) fiberglass lamination. The only metal parts were surrounding bearings or bushings, and of course the motor and drive-train. Watching it perform really opened my eyes to nontraditional fabrication methods. I'd estimate it's 0-60 was in the 3-4 second range, but it's net weight including batteries was only about 200 lbs. Imagine an electrically driven clear fir and birch ply racing Kart and you're close to what this vehicle was.

For a foam-core type of build I would be inclined to include conduit within the foam to facilitate future upgrades. I would use the interior walls and cabinets structurally, but they would be bonded into place after the main walls had been laminated rather than trying to laminate around all of those corners from the get-go.

 

[pods8]

For a foam-core type of build I would be inclined to include conduit within the foam to facilitate future upgrades. I would use the interior walls and cabinets structurally, but they would be bonded into place after the main walls had been laminated rather than trying to laminate around all of those corners from the get-go.


Fairly close to my game plan. I'm not planning to bury conduit in the lower shell walls because I'll have enough cabinets/benches to visually hide most wiring. In a few limited spots (like across the dinette from one bench to the other) I'll use the corner style surface mount raceway along the floor most likely, or build my own chase out of something more visually appealing. In the upper part I'll bury conduit to where the lights/fans are at and maybe a couple other locations.

I do intend to bond the cabinets structurally just as mentioned. Either I'll do the wall of the cabinet directly to the camper wall (thus back of the cabinet) with fillets to take care of the stress concentration or I will do a strip that is bonded to the wall to which the cabinet wall will be mechanically fastened (thus giving me the ability to remove/remodel the cabinet more easily if needed). I'll stew over which methods to mix/match when I get there.

On the subject of wood, folks bag on it a lot but that is mainly due to experiences with lower craftsmanship campers that have leak issues. When wood is properly used and sealed up, esp. with stuff like epoxy it performs quite well (just look at numerous wooden boats, when done well/right it lasts, when done poorly it doesn't).

 

[Nimbl Vehicles]

For a foam-core type of build I would be inclined to include conduit within the foam to facilitate future upgrades. I would use the interior walls and cabinets structurally, but they would be bonded into place after the main walls had been laminated rather than trying to laminate around all of those corners from the get-go.


That's how I build mine. The foam is cut on a CNC with channels to accommodate conduit for all wiring.
The interior parts are then bonded to the main structure to form a "superstructure"
This also eliminates all mechanical fasteners, so no screws or staples can come apart.

 

[John D]

Annually, a couple hundred hand built new aluminum frame campers are delivered, fully fitted out, at a price between $12K to $15K and with an empty weight between 600 and 800 pounds. What is the price and weight range for composite resin campers? How many are delivered each year that weigh less than 1000 pounds? I'm asking because I don't know the answer to my question.

 

[Phird05]

Annually, a couple hundred hand built new aluminum frame campers are delivered, fully fitted out, at a price between $12K to $15K and with an empty weight between 600 and 800 pounds. What is the price and weight range for composite resin campers? How many are delivered each year that weigh less than 1000 pounds? I'm asking because I don't know the answer to my question.


Hey John D,

This has been talked about for some time and there is a very big misconception out there regarding the weight issues. The weight that some manufacturers advertise is empty or unfinished weight. Others advertise finished or weight with options. If you took any of the top three or four pop up manufacturers and put the same options in them and weighed them they would all be within a couple hundred pounds of each other. There are posts on this forum where people have weighed their campers and much to their surprise they weighed well into the 1,200 to 1,300 # range. Let's face it, we all live in the same atmosphere, so no matter what options you put in a camper, it will weigh the same in yours or mine! The weight argument is nothing more than a sales tool. There's nothing wrong with that but one should be aware of the facts when they are about to drop some serious coin on one of these units. I have said it many times in the past, the weight should NOT be a MAJOR factor when deciding what you want in a camper. More importantly, look at as many manufacturers you can, narrow it down to the top few and spend time in those campers and make your choice on what feels right to you. Look at all the aspects of the camper, storage, fixtures, seamless roofs and counter tops (no way to have leaks), capacities and so on. Without getting too long winded, I had several items that made my decision for me. If you want more information what my experiences were feel free to PM me.

Good camping!

Paul

 

[pods8]

Annually, a couple hundred hand built new aluminum frame campers are delivered, fully fitted out, at a price between $12K to $15K and with an empty weight between 600 and 800 pounds. What is the price and weight range for composite resin campers? How many are delivered each year that weigh less than 1000 pounds? I'm asking because I don't know the answer to my question.



Composite campers are relatively knew so you're not going to see big numbers there yet in comparison but that doesn't make one more or less superior in my mind at all. Composite campers currently tend to cost more (they're also more labor intensive and lightweight materials cost money too) but that doesn't readily factor into a "superior" frame. It could be discussed for practical or best all around, etc. In the past I think XP mentioned a shell weighing around 600lb, not sure if that is true on current design and if that at least accounts for the hydraulics and a minimum battery bank needed to work them or not to make the camper functional.


Looking at my rough numbers on my homebuild I'm fairly comfortable that I'll be under 1000lb dry weight (ie no water/gear) with my camper including all the appliances and a 160lb battery bank. We'll see where the final numbers fall but I just changed out my truck to a 3/4T so I'm not going to freak if I come in a little high even though I don't think it will.

 

[John D]

There are couple thousand aluminum frame light weitht campers out there. Most of them are on half ton trucks or equialent. If you cannot tote your camper safely on a half ton truck, it is not a light weight. On my last trip of 6300 miles, I averaged 16.5 MPG with lots of interstate driving (where my truck gets the worst mileage). My truck has completely stock suspension and drive train. That is using gasahol almost exclusively because that is all we could get. With pure 87 octane gas we do about 18.5 MPG. There are planty of campers to choose from if you are going to run a 3/4 or 1 ton. We are talking about light weight campers, aren't we? Weight does matter. If you want to drive a half ton truck, which is the granddaddy of all truck campers, you must pay attention to weight.

 

[pods8]

JohnD you're kinda bouncing around a bit. Is there something specifically you want to discuss and weigh out pros/cons?

Yeps lots of campers on 1/2T trucks, also lots of them at or over GVWR too. I don't think that is as major of an issue if you know your limitations though. I personally went to 3/4T for stronger brakes, more payload, and larger gas tank. I could have spent money on upgrading the brakes and gas tank on my 1/2T but rather than do that I used that money to jump into a 3/4T that already had what I wanted plus a bit beefier frame/springs so I didn't need to worry if I ever wanted to haul more than I currently do. Doesn't really have anything to do with camper construction though.

A main reason XP, for instance, is calling for a larger truck is because of the large water tanks on it. Put a 100gal of fluid capacity in an aluminum camper and 420ah of battery and you're not going to be hauling it on a 1/2 safely in most cases considering that is 1000lb of extra weight. This is more of an option issue than a construction issue. XP is trying to cater to longer expedition travel than FWC/ATC/etc. typically do in their stock configurations.

 

[ntsqd]

An observation on weight: years ago my great uncle could not figure out why he couldn't get his 28' Class C motorhome above 6 mpg (carb'd 460, uphill battle to start with). Nothing that he did had any effect on the mileage. Until he realized that his wife had outfitted the m/h's kitchen the same as at home, with the same complete set of cast iron pots and pans & everything else...

For me the disadvantages of an aluminum frame are fatigue life first and cold paths second. Cold paths will be true for any metal framed structure, not just one of aluminum. I had been playing around with a design for a small camper similar to an Alaskan NCO using 1" square tube. Tempting to go see if it can be done with two offset structures of 1/2" square tube so as to create a mostly discontinuous cold path.

 

[John D]

Pods8, Sorry I'm bouncing around too much. I don't want to play the game of “scientifically” comparing pros and cons. I respect the fact that you are a grown man and can make decisions for yourself. Me too. Since I put our old Keystone on our little F-150 two years ago, we have driven it 33,000 all camping miles. Our previous Chevy 1500 has 425,000 miles on it when we shifted the Keystone over to the F-150. Half of that was camping trips. Before that I had other campers, shell camping before that, car camping before that, tent camping before that and sleeping bag camping before that, for more than 60 years. In between, my wife and I sailed a 31 foot Ketch around the world, which was two years of water camping. Almost anything can be proven with statistics.

Others have camped as much as I have, and there are a few right here on this forum. They will attest to the fact that when you think you are in the most remote place on earth, first thing you know, some hippie will pass you in an old yellow school bus, waiving as he goes by, or a dude in an old Crown Vic. He will have a big smile on his face, probably a cute young girl with him, and always a dog or two. Truth be known, he may be having more fun than I am. See the following;

There are lots of people who read this forum to learn how to do this. Maybe they are young marrieds with a new baby and they need better shelter than the tents they have been using up to now. They should know the one ton trucks and cutting edge campers are not necessary. Such rigs are expensive. They cost more to run and more to keep up.

A good used aluminum frame camper can be had for 5K to 10K and a pretty good half ton for 5K. A lot of folks have found this answer and spent a lot more time camping than playing with their rigs. Why I am writing? Just to let them know it is OK and the aluminum frame lightweight is the best solution I have found ... in my limited experience. I want to see you follow the guy in the Crown Vic with your rig. I am not! John D

 

[pods8]

Weird thread. You started it saying you wanted a discussion. Not really sure what you are going for here or why...

 

[craig333]

Can and can't (camp, offroad etc) is one thing, I think most of us are more interested in what can do it well. I've seen some cars get well offroad. I've also seen many abandoned when they could no longer make it. I've personally offroaded a plymouth belvedere. It didn't work well even though yes, it did go a ways down some dirt roads. Cadillac hill is so named because a caddy is not well suited to the Rubicon.

Frequently people mention some car or 2wd pickup will be in some remote place in Baja. I seriously suspect thats more economics than anything else. I'd bet most of those people would rather have a more capable vehicle if they could afford it.

I've also had to get out and push a VW bus uphill. Was it great to get out there anyway you can? Sure. Its also a heck of a lot better with a truck and camper thats designed to do the job properly.

 

[John D]

Chris McCandless is a hero to a lot of people. The type of camper Chris was using probably would not have altered the outcome becaue he had not invested properly in himself. (pos8 will ask, what's the point?) Sorry, if it doesn't register, than it just doesn't register. I guess I am sort of with Chris. It is a shame he died. From what I have read about him, he seems like a great kid.

 

[Desert Rancher]

He should have remained at Salvation Mountain.
Leonard would take care of him...