3-way square tube corner

thingiverse

I wanted to build an enclosure for my 3D printer, and I wanted to use aluminum square tube stock as the frame. It's designed to print without support. The included STL is for 1 inch square tube. It mates with this stuff: https://www.homedepot.com/p/Everbilt-1-in-x-96-in-Aluminum-Square-Tube-with-1-20-in-Thick-802537/204273939 Since I was going to adhere panels to the outside of the box, there's no mechanism to lock the tubes to the corner. The source Solidworks file is attached, so you're empowered to change dimensions or add features.