The tabs, and the slots they fit in on the main bracket, may need some cleaning before they'll fit right.
I used 10mm M3 screws to attach the tabs to the motor - your motor may vary.
I used 3/8 inch #4-40 screws to mount the Printrboard to the bracket. 10mm M3 screws might work as well.
- Test fit and clean up tabs and slots if needed
- Attach Printrboard to bracket
- Slide tabs into slots
- Attach tabs to motor