Delta endstop mount

Endstop mount for a Delta using these metal corners: https://www.aliexpress.com/item/Colorful-all-metal-3D-Kossel-printer-2020-aluminum-alloy-delta-angle-corner-kit-Kossel-corner-kit/32787024606.html

I'm upgrading my Zonestar D810 using 2020 metal corners bought from AliExpress. I'm still mounting the motors on the top of the printer, and need somewhere to mount the endstops. I want these to be adjustable as well... that's still a WIP. Probably this will work OK with other Kossel-based deltas using these metal corners.

Use an M4 screw and nut to attach to the existing hole in the corner piece.
Use 4gx12mm countersunk woodscrews to attach endstop to mount. Self-tapping screws as supplied with the kit are probably OK, but they don't fit tightly into the endstop holes.

I removed the metal levers from the endstops, partly because they fell off, partly because I think it's more accurate without those levers and their sloppy axles. This will still work with the levers if you want t