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Windows In, and some History

Last night, we installed the five German Seitz windows.  Anna and I discussed it a bit, because there’s an error in my design.  There are two kinds of windows available: top-hinged and sliding.  Each has its advantages, the most critical being that top-hinged can be open in the rain, and sliding can be open while moving.  It’s good to use at least one of each type on every wall, so that in any condition the camper can naturally cross-ventilate.

The design flaw lies in the curb-side bunk window.  It is top-hinged, and the entry door can damage the open window if the door is allowed to open 180 degrees.   Instead of ordering a new window (like pulling teeth from the US distributor), we kept the design and plan to be careful and install a door-travel limiter.  It does allow the perfect combination of window types for ventilation, and we’ll be grateful when camping in the rain.  Here are a few shots of the windows.  Note the integrated fly-screens and sun-shades..

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After building five campers, the last two (both designated AATREC-FM204) have used a fully composite upper body, built on a steel floor.  To this point, I have not released photos of the system I use.  However, this is a good time to publish a little peek at how it all goes together.  It’s really pretty simple.  I fabricate the steel floor from square tubing and then have it powdercoated…

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The composite walls and roof are made from a composite foam-cored panel licensed from a company in Belgium, Composittrailer.  The upper system is bonded to my steel floor using a proprietary composite pultrusion.  This system yields an incredibly strong three-point torsion-free chassis interface, a low center of gravity, light overall weight, good insulation, and an upper structure virtually immune to corrosion.

Is this stuff strong?  Absolutely!  The company used to have a video showing a drop-test from 10 or fifteen meters.  A container was suspended by a crane and dropped onto one corner on concrete.  Sustaining minimal corner damage, the structure remained completely intact.

This entry was posted on March 17 2009 at 08:16 and is filed under AATREC Construction. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response or trackback from your own site.

5 Responses to “Windows In, and some History”

  1. boblynch says:
    May 1 2009 at 07:52

    Looking to build a flatbed for an F550 that will haul a modified truck camper. Curious about your floor design; what dimension tubing did you use for the floor? It looks like 2×2 for most and possibly 4×4 for the front section that mounts to your pivot frame. How did you determine the frame pattern? What is the rationale for the double 2×2 on the outer square vs. a larger tube? Thanks for any input.

  2. Darrin says:
    May 1 2009 at 08:56

    Tubing is various size. Much is 2×2x3/16 wall, the main supports are 4×4 front, 4×2 rear, 1/4″ wall.

    As for the frame pattern, that’s 20 years of fabrication experience. First, you must consider how you’re mounting the platform to the truck. Once the mounts are complete, you need to consider what you’re mounting inside or under, and where it’s going. That big 4×4, for example, is directly underneath the 50 gallon water tanks.

    The dual tube on the outside is built to accept the proprietary Composittrailer pultrusion, which interfaces the walls to the floor.

  3. boblynch says:
    May 1 2009 at 10:29

    Thanks for the quick reply. In my case I’m looking at a standard truck camper with boxes down the sides (but fixed to the camper) and boxes underneath (fixed to the aluminum flatbed). I’m trying to determine the best frame pattern for the flatbed to minimize stress the camper body. Also, struggling with a flexible mounting method that doesn’t increase the cabover space between camper and truck. The typical 3-point and 4-point flex systems are too tall for my application. Ideas?

  4. Darrin says:
    May 1 2009 at 20:45

    There’s not much I can say to really help out. Your problems are common, as everything in life is a trade-off. An example: You want flex, but don’t have space…

    That’s where engineering and custom fabrication come in. Ideally, you don’t want to transmit any torsion to the box, to avoid breaking things inside.It’s not so much about increasing frame flex - too much and BANG! - you’ve broken a frame. It’s all balance.

    I’d get hold of a Ford BBM first, to see what the engineers there say about mounting things to their chassis. You want to be sure to “read the directions”. Not everyone does, and they pay the price. I know of a couple recent Fuso frame breaks, due to poor design (compounded by gross overloading.)

  5. boblynch says:
    May 2 2009 at 10:42

    Thanks. Best of luck on your build.

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