As usual for this project, my design for the treadsection
was determined by the materials available. I didn't want to make a wooden
treadsection, but I don't have the facilities for welding aluminum. So,
I'm making mine from aluminum, but held together with bolts, blind rivets and
epoxy. To better distribute the load, the axles for each side will go all
the way across the base, and will be supported in part by a square-tubular
alumuminum frame which will also provide a solid base for the interior leg
supports. I found a local supply of 1/8" aluminum sheet, and I will use that
sandwiched between two thicknesses of .05" aluminum to create a .225" vertical.
A skin of aluminum sheeting (the roofing variety) will cover the base when
finished, to provide a smooth surface and cover any seams.