Quote Originally Posted by Clive S View Post
You will need to put slots in the motor mounting to enable you to have adjustment to tighten the belt. It is quite normal to have 30 - 40 mm adjustment. >clive
The slots need to be 1mm wider than the OD of the motor mount hole. Some servo motors will not allow that movement because the center part is bigger than nema 23 for example, but i can assure you that even 5 mm possibility to move is ok if you use that calculator. Just tested that theory with my servo motor mounts where it was not possible more play. So on a Nema 23 +-10mm both side from center hole is more than enough. Care should be taken if the mount is milled deep into a plate and the motor needs more play just to pass through and enter at its spot.