Couplings for extruded aluminum tubing 0.5" square outside with 0.04" walls

thingiverse

Some time ago, I inherited a collapsible trade-show display wall consisting of several dozen 0.5" square aluminum extrusions with 0.04" thick walls, along with a bunch of plastic bits, rivets, and webbing straps. The whole thing expands to about 8 feet square by 30" thick, and collapses to fit in a 1'x1'x3' shipping case. They'd broken a few tubes over the years, so they threw it in the recycling. I rescued it with the idea of drilling out the rivets and having lots of extrusions to play with. I decided to model couplings for various combinations in order to facilitate assembly of projects. Update 07/01/19: I just noticed that I forgot to inset the sides on one leg of each shape, meaning that leg won't fit into the tubing. Sorry about that; I hope you checked before you printed any. I think it's fixed now. I've also added rounded edges to make it easier to start them into the tubing. The 2-way-corner doesn't have those yet - ran out of time just now. Will add them soon.