4040 modular corner

I had a dream about building a massive 3D printer until I got on Amazon and saw the prices for extruded aluminum rails. I tried printing my own rails, but they always seemed to splinter on the ends when I'd try to join them at a corner. So, I created my own part based on the work of abanobblackbox. Its not much, but for a first try by an old dog, it suits my purposes! Stay tuned for a 4040 straigtht piece keyed to mate with this one...