Angle brace for RC airplane

This is an internal 90° angle brace for "foamie" RC airplanes using square foamboard tubes. In particular, I designed this piece for an [Experimental Airlines Axon](https://youtu.be/-gFYDk5QFhQ) to keep the fuselage tubes square and prevent racking.

The braces weigh about 1.2 g each (PETG), and install easily with hot glue. A pair of braces will fit side-by-side (see photo) in a nominal 68-70 mm (external) square tube made of Dollar Tree foam board.

They also work as mini-bulkheads for mounting small components, and have three small holes for routing wires, pushrods, etc.