Monday, January 5, 2009

History has this ugly habit of repeating itself

Well, the KIT almost went down for the count last night when the wood behind the reinforced steel bracket holding the passenger side front jack broke in two. What caused the stress on the corner that caused it to go with a long snap and bang, is not entirely certain, but I'm going to wager on it that the ground under that side was unstable but not enough so to be directly noticeable. (I.E. camper didn't sink in when it was raised, problem occurred during the lowering to ground portion.)

From the looks of it, the point of failure was caused by a design mistake I made when we reinforced the original mount. I upgraded the lag bolt diameter, but not the length. The end result the lag bolts were going all the way into one of the boards and the other was bearing all the load.

Anyway, here's some pictures of the damage:

The new brackets have 5 bolts spread across two arms that bolt through the underside of the wings, in addition to 8 3/8" grade 5 bolts that clamp the massive 4" wide, 1/4" thick angle iron that goes up the corners of the camper on the inside and out.

These brackets are massive, the outer one weight roughly 10-15lbs, and the backing plates weight 5-8 (I'm guessing here).

I had to forgo plywood backing on the inside (something I would have liked to have been able to do) and directly glue the inner piece of 4" wide, 1/4" thick angle directly to the frame with 3M 5200 Marine Adhesive/Sealant. There just simply wasn't enough material in the corners to accommodate the plywood.

Some interesting finds I made along the way were that the driver's side front corner was rebuilt using 1x10 solid hardwood boards, where as the passenger side (the side that failed) was still using the original 1x3 (Not 1x4 for some reason....) lumber.

The only damage that occured when the failure occurred was the outer edge of the wood was snapped off, the remaining timber was solid and I bolted through it.

I have managed to arrange a deal for a set of used Atwood mechanical jacks, but I won't have the funds to obtain them until well after this trip. The Reico Hydraulics are going away, I'll take using my cordless drill to wind the jacks down over pump jacks that constantly destroy their clevis pins in mid lift...

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