i had plans to try and build a collapsable drop in using 1 inch steel tubes, but i never got around to having the shop class make it. mine woulda fit on the roof or something. the problem was making the actual parts cuz you couldnt use generic materials.
Steel tubing would be really heavy. I have a bunch in my garage that I have used for different purposes. It's amazing how much 4 steel tubes weigh. Anyway, that's why I would go with aluminum.
