I've got some 3D printed parts on my L2 build that will fly, but I'm not sure when the project will be wrapped up. So... I'm submitting my body tube squaring tool into the contest. It's a very simple design. The clamping section is designed over sized to allow for the sanding bar to be slid forwards and backwards to maximize use of the sandpaper on it, rather than wearing out a small section and having to replace it. It's designed around a GP 6" bar sanding tool, but it's not hard to adapt the idea to whatever you've got on hand. The clamp uses 4 #6 screws. The idea was a quick, cheap and easy tool to square up the ends of the tubes on my Mad Cow Level-2 kit. Depending on how far the tube is out of square, a few twists should square it right up.