pic: 6WD Riveted Frame Development

[MrForbes]

1726 did a riveted chassis this year, made from 1 x 4 x 1/4" pultruded fiberglass channel, and .060" sheet 3003 aluminum for the full belly pan and top gussets. We used 3/16" rivets from the hardware store. It worked just fine. Also we used cantilevered axles, mounted directly to the fiberglass, and had no problem with them. There was quite a bit of design work in this chassis, so fabrication and assembly was straightforward.

The cantilevered axles worked because they were mounted with flange nuts with a 1" diameter bearing surface, and the fiberglass is thick enough that it would not flex or be damaged by the load. There were no lightening holes in any of it. Fiberglass is about half the density of aluminum, so the weight of 1/4" thick fiberglass is about the same as 1/8" thick aluminum of the same size.

I think there are some pictures on the NERDS photo gallery...