Remixed the excellent MPcnc 525 Motor Cap by Kselleslaghs to reinforce the rings at the bottom for the bearing bolts as they kept breaking on me, and to countersink the M3 screw holes. Now a M3x16 fits perfectly.
Remix 2 adds extra reinforcements to the top section, in my original prints the countersunk portion of the holes was fairly thin at some points. I have printed this version to verify everything still fits but I am still using the v1 remix on my machine without problems.
3D Mars PLA
Printed in the orientation of the STL ("top" on the build platform) they printed great without supports.