Feet for OpenBeam extrusions.

These feet are for OpenBeam (15mm square) extrusions but could be rescaled for other sizes such as 80/20, MicroRax or NanoBeam.
If you like working with t-slot check out my product:
https://www.kickstarter.com/projects/bossgizmo/nanobeam-helping-makers-build-the-smallest-things