Needed adjustable Z-motor to line up my Z-rod and printed the source file, only to descover that it was for bigger size screws.
As it needs 2pc T-slot-nuts, and I only had M3 of these, I made a "copy" (slightly altered) with holes suitable for M3 screws instead.
2pc T-slot nuts M3 size
(See pics for installation)
Printed in Z-ABS because my Zortrax M200 does it so well and the Sky blue ABS is the colour of most upgrades for my Ender 3 Pro. Would work with PLA or PETG too I believe.