Attaching an Aluminum Camper box to Aluminum frame....

[mletschin]

I have been doing some searching and found multiple answers but nothing with much meat to it so I come asking for thoughts.

I have a Schutt LTT-HC Trailer frame (formerly a military generator) that I have taken down to just the framing, suspension and wheels.

I am building an aluminum box frame out of 1" square 1/8 wall aluminum tubing that will get bracketed, welded and skinned.
The part I need is how do I attach the camper box to the frame? I am looking at rivnuts in the frame with large bolts and washers through the camper framing, probably 12-15 points at least. I also have looked at adding some VHB tape for extra hold on the frame rails where it will contact the lower skin.

Is there a better way or does anyone have a reason this would be a problem?

Heres a couple shots of the framings currently.

 

[eatSleepWoof]

I would only use rivnuts in places where the back side of the bolt cannot be accessed. In your case I would drill all the way through the trailer frame and through-bolt without any rivnuts. In cases where the frame channel end is exposed and you have access inside it, bolt through just the top layer of the frame.

Alternatively, bolt/weld-on some angle to the original frame, and bolt your camper to the angle. 12-15 attachment points is more than enough. Keep it simple.

 

[IdaSHO]

If you are to bolt it together (I would) Id suggest using stainless hardware. It will minimize any galvanic corrosion. Just be sure to use more and/or larger fasteners than you would with a more conventional grade 8 bolt.

 

[simple]

And use nylock nuts with big washers to spread the load. You wont be able to torque the nuts very hard because it will crush the tubing. I'm not sure how much the VHB tape will add since you have relatively small contact points.

 

[vintageracer]

Sleeve all your drilled holes in tubing to reduce/eliminate the chance of crushing the tubing by overtightening. You don't need to weld in the sleeves. That would be better but not needed for this application.

 

[rruff]

I agree that reinforcing the attachment points and spreading out the load a bit are good ideas. Maybe weld a plate or gusset on your camper, and bolt this to the trailer frame. Unlike a lot of chassis, your trailer should be torsionally stiff, so it won't take much to keep it in place.

 

[Alloy]

1/8" aluminum isn't durable enough for bottom framing. The design is the opposite of the ideal with the strongest sections at the top. The ideal would be 3/16" or 1/4" alum. tube/angle on top of the steel tube with neoprene (rubber and aluminum are not compatible) that is attached to the aluminium with urethane (Sikaflex or 3M-5200) caulking.

These verticals should align with the steel cross member or the 1/8 alum. will crack.




and these corners needs (aligned with the side not the center of the tube) gussets. Depending on the type/thickness of the sheathing you may need more.