The Motor Mount Plates have M3 holes that fit both 16mm and 19mm patterns. The Motor Mount Plate should be printed with 100% infill to allow the mounting screws to be very tight without deforming the plate.
Flange head screws have wide heads that are not tall. Wide flange heads distribute loads well against the Motor Mount Plate. The short flange head fits properly in Arm’s round pocket under the plate.
Screws must be the correct length to not touch the parts inside the motor. Screws that are 6mm long work in most cases. Its important to check for clearance while installing the screws.
Flange head screws with low heads fit in the round pocket on the Arm below the Motor Mount Plate.
Button Head screws have small heads that give good clearance with the motors.
10mm long screws are recommended.
Steel washers and M3 nylock nuts are recommended.