[hrench]

As an engineer in the truck-industry, I've taken Panther Robotics 1108 in a different direction. We use steel.

It costs about half as much, its half-again stronger than aluminum and if it bends, we can just bend it back without losing strength.

We have a flux-core wire-feed welder in the shop, which is inexpensive to operate and the kids learn to make some great looking welds. Add a bracket? don't need to drill and bolt--just weld it on! Also note, we've never had the money for aluminum welding.

Mostly we use 1/2" x 1/2" x 0.062 wall thickness square section tubing, but also on round parts we use EMT conduit. All available at the local farm store or Home Depot in the city. Also cheap at mcmaster.

Takes up less room too. Can't imagine building in 1/2" tubes in aluminum. Would fold like tinkertoys. Steel is super strong.

And oh-yeah--our robot weighs 105 this year. No lightening holes either. Yes, steel is heavier, but we just use less.

I remember aluminum robots put together with rivets--they were always rickety and wobble. These are solid.