90 deg extrusion bracket

thingiverse

I'd never spotted a bracket like that one before, so I figured I'd create my own instead. It does a great job of holding the extrusions at a precise 90-degree angle. The only tricky part is getting the second side T-slot nuts in place - I used an Allen wrench to gently slide it into line with the hole (check out the picture) and that worked perfectly for me. The holes accept M5 screws, specifically ones that are 8-10mm long.