Customizable square tube corner bracket

Description

This corner bracket is designed to connect square tubing to make a box shape. It slides into the square tubing and has no holes to attach to the tubing, so it's a friction fit or glued in. I designed this for use in my perpetual pendulum wave project (https://github.com/jbeyers/pendulum_wave). At the time, the only corners I could find were printed on their side, which had 2 problems: They needed support and/or post-processing The print layer orientation made one of the posts weak. This design avoids both those issues. The orientation of the layers make it so that a single layer extends into all the tubes, which strengthens the part. It prints without support on my very, very homebuilt printer.