Square Tubing Connectors - Complete Set

This is an original design from the author. This is not my design.
I use these connectors often. Very comfortably.

On the thingiverse website. It’s hard to find everything, I uploaded these files to this site so as not to lose them.

This provides the complete set of all nine possible square tubing connectors. Also provided is a special fixture to allow you to find the optimum fit for your tubing.

 The default STL files include all the fittings for 1/2 inch (12.7 mm) square tubing. The inner dimension of 9.4 mm should provide a nice snug fit. If not, the fixture should help you determine how much to adjust that value.