Brainstorming the mounting of the sofa bed

[zuren]

Nothing is ever easy! So what do van converters do when the mounting points of a major component (like a sofa bed) line up with the frame rails of the van?

I have my sofa bed in the van (an Atwood manual frame) and have been playing with positioning. I'm setting the interior up like a Sportsmobile RB50 layout. I think I have it where I want and to the best of my measurements, the mounting points on the sofa frame are directly over the van frame where it comes closest to the body. I'll be using quick release seat clamps that use a bolt that goes through the floor. There might be 3/4" for me to get my fingers between the body and frame under the van.

I'm looking for solutions. I'm thinking my options will be something to the tune of shorter bolts or as extreme as a body lift but that may open up other issues. Shifting left/right won't work (space is already tight) and I would have to shift it over a foot forward to make a difference. I thought I would confer here before I get my brain in a knot!

Thanks!

 

[Herbie]

Zuren, this seems to happen to all of us. I know of at least one other guy on AstroSafariVans whose bed lined up with the rails - apparently he welded blind nuts in somehow.

Predictably, my dodge conversion-van bed lined up in the same way on my Astro. In my case, the holes lined up more or less with the outer edges of the frame rails.

You can sort of see my solution in the full-size version of this image.

Basically, I offset the mounting holes to the right about 1-3/4" or 2". My seat is semi-permanently attached (no quick release hardware), so I ran the right-side bolts down through the mounting flange, through the floor, and then through big backing washers. There was BARELY enough room for the washers up against the outboard side of that frame rail. In fact IIRC I had to touch one of the washers against a grinder to put a plat spot on it to clear. (Three bolts per side, BTW)

So now the seat is offset to the right, which puts the left side mounting flange and bolt holes DIRECTLY over the center of the frame rail. My solution here was to basically fab up a separate steel flange (3" wide) and drill offset holes in it. I then drilled holes in the van floor outboard of the frame rail (matching holes on the other side, more or less) and then bolted through the new flange, basically capturing the seat's mounting flange between the new flange and the floor.

I've seen similar arrangements used for "quick release" brackets where one side of a captain's chair slides into a rail and the other side is fastened down, so I feel pretty good about this, especially since the new "capturing flange" runs the full depth of the seat's mounting flange (about 24") and is heavier gauge than the seat's original mounting surfaces.

I suppose if one were a bit nervous about this approach, the other option would be to weld a wider flange on to one or both sides of the mounting base to move the mount holes outboard (or inboard if the flanges bent inward) of the frame rails - essentially connecting my "capturing flange" to the original mounting surface.

I was originally wanting everything to be quick-release (or at least quick-ish), so I was planning to capture nuts onto the bottom side of the van so that I could just pull the bolts from the top to remove the bench, but as I've added a battery box behind the seat, etc. that would now be a serious multi-step project that I just can't see tackling. If I seriously need a cargo van or a 3rd row for weekend visitors or something, I'll consider renting something rather than go through the hassle!

I'll try to get closer pictures but I'm not daily driving the van right now so I'll need to remember to open it up when I get home.
EDIT: Here's one more picture where you can sort of see the capturing flange on the left side:
https://picasaweb.google.com/lh/photo/yP65Mbpv5KgrrwAlR2z29w?feat=directlink

 

[Ozrockrat]

How about a wide mounting plate under the floor

How about having a mounting plate that is held in place by bolts that are outboard of the frame rails. Flat steel with blind nuts welded in place slid over the frame rail. Holes drilled in floor from above for the inside mount. Have a buddy hold it in place while you bolt the frame in from the inside then drill the holes for the holding bolts. That way you can remove the frame bolts inside anytime and leave the plate in place. The plate also gives a nice wide surface for added mounting strength.

 

[1sweetvan]

Rivnuts. Not sure if they are available rated for your application, but they sure would solve your problem.

 

[Railvan]

Without seeing the van this is just a general comment, but I'd look under the van for the best place to bolt through, and then modify the seat frame to make that work. Adding metal to make the frame wider, longer, or whatever is needed, by welding to the seat frame seems easier then working in some difficult location under the van.

Brian

 

[zuren]

Without seeing the van this is just a general comment, but I'd look under the van for the best place to bolt through, and then modify the seat frame to make that work. Adding metal to make the frame wider, longer, or whatever is needed, by welding to the seat frame seems easier then working in some difficult location under the van.

Brian

I'm considering all options at this point. Adding plate steel to the sofa frame to change the bolt location was one of the first I had and is still viable. I'm not in love with semi-permanently altering the sofa frame and I wouldn't be using the mounting hardware I ordered but it is still an option.

I looked underneath a bit closer and a body lift would be possible with some trimming of the fan shroud in the engine bay. This method would be mostly reversible if I sell the van down the road. The fan shroud would still be trimmed but unseen. I plan to be back underneath tomorrow to continue measuring.

Safety is paramount. The Rivnuts may work but the one thing I'm trying to prevent is pull-through in an accident. This sofa will eventually have belts to transport people legally.

 

[dluty]

Have you ever heard of 80/20?? Great product. You could run 2 strips down the length of the van and have infinite places to place connect the bed.

http://www.8020.net

my 2 cents-

 

[r_w]

How about having a mounting plate that is held in place by bolts that are outboard of the frame rails. Flat steel with blind nuts welded in place slid over the frame rail. Holes drilled in floor from above for the inside mount. Have a buddy hold it in place while you bolt the frame in from the inside then drill the holes for the holding bolts. That way you can remove the frame bolts inside anytime and leave the plate in place. The plate also gives a nice wide surface for added mounting strength.

This. You can do it cheap with a 6" chunk of strap iron with the nut welded near one end to be the fender washer and strap to position it, but bolting it solid makes it much easier in the future.

I have positioned nuts and fender washers in position by taping them into a box end wrench, just be careful to not cross thread them when starting.

And FWIW, my van came with large self tapping bolts in those spots. not cool.