Why are Truck Campers so poorly made?

Desertboy wrote:



After 45 years,

69 Avion wrote:
Riveted Aluminum Construction is hard to beat. All the Avion campers still out there show that they are able to stand the test of time. Also, as in aircraft construction, non pressurized structures will last a very long time. Constant pressurization and depressurization will take it's toll on any lightweight structure. Campers don't have this issue. The real issue with riveted aluminum construction is the cost.

I have to admit I have a soft spot for the Avions and Airstreams. I nearly bought an Avion TT in the past. After looking at the Brochure-links, provided in my link above, I fell in love with the elegant Mark. But, it was also a bit more than I wanted to spend at the time, even used.

There is a different stress that happens to travel trailers as opposed to truck campers. Travel trailers (and 5vrs) ride on centrally located axles that almost act as one "roll center". This means that if the camper is subjected to different wheel heights, side-to-side, the camper merely rolls one way or the other mostly as a square, intact unit. Truck campers (and motored homes) have a unique problem in this respect. Since one axle of the motored vehicle is considerably forward of the other, the entire structure may be subjected to a significant torsional stress from uneven roads (or off-roads).

As an example, I did experience a couple of examples of this on an old 1976 chevy truck I used for work on new home construction. On a very cold day, I parked with one front wheel raised by a snow pile to leave the narrow plowed job access path open for other workers. Unfortunately my plastic dash cracked right down the middle from the truck frame flexing in tune with the crooked landscape. A similar thing happened on another occasion where the windshield cracked right down the center from frame, and therefore cab, flex.

These were not high speed incidents and could easily occur off-road with a truck camper attached. In that case I would rather not have the smooth aluminum sides of an Avion for fear of eventually cracking around the rivets and fear of rippling the exterior panels. The best TC structure, IMO, would be sided with ordinary, cheap ribbed aluminum. The ribs can flex to take up twist and I expect they would last for many cycles since the stress is not concentrated right at a small area of attachment. I would also prefer wood framing because of resistance to cracking, and ease of repair if it does.

On the other hand, the smooth Avion TC must either stretch the aluminum or slide the rivets to flex. If the beautiful example shown above is not cracked around some rivets, then I am either wrong, or it has not been substancially used off-road in those 45 years.

As further evidence of flexing being a concern while truck mounting, I point out that some of the very expensive "World Safari" type truck campers use a three point (think tripod) mounting system for the camper cabin. They are usually mounted to the truck frame on either side right behind the driving cab, and single point mounted at the rear. Should the truck frame twist, and they all do, the cabin can maintain it's square shape and therefore it's integrity.

I believe the worst truck-camper scene would be a solid-welded aluminum frame, covered by Filon, the exact type that is now present on my current Keystone TT. The cabin body does flex just from putting stabilizer jacks down. The rain gutter is level, front-to-back, until I lower the jacks. Then the gutter develops a 3/4 inch sag in the middle, allowing rain water to dribble down the center of the wall instead of off the ends of the gutter. I have no idea whether or not some of the brittle frame welds have already cracked. They are hidden.

As a side note, with a lot of flexing, I would expect caulking to fail sooner on any off-road camper.

Wes
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