Summary

Simple little carriers that prevent a m3 nut from sliding in a 1515 extrusion channel. They also position the nut nearer to the face of the channel so they are easier to capture by a m3 screw. The hole in the back is slightly undersized so it acts somewhat like a nyloc.

They probably will work with M3 hex nuts too.

I printed them out of PLA.

NOTE: They are designed for 0.2mm layer height with first layer being 0.3mm. If you use 0.2mm for your first layer, you should scale them to be 0.1mm taller in Z with the slicer before printing.

F360 source included if you need to tweak them.