Modified for 1515 aluminum extrusions, and no board mechanical endstops (9mm spacing).

Extra thick to make the endstop more prominent for use with linear rails.
M2.5 screws for the endstop, with nuts to hold it together.
M3 screws for the extrusion, with nut for clamping.

PETG
.2 layer height
.6 nozzle
20% infill

This object was made in Tinkercad. Edit it online https://www.tinkercad.com/things/5z4rYuzcwJH