this is a remix of this thing: https://www.thingiverse.com/thing:2809788
when I first downloaded this I added a 4th hole because the motor has 4 holes. and I believe they should be used.
this caused the belt holder to hit on the 4th hole arm, so I made the belt holder thinner.
this worked well but now the belt holder was hitting the flat upright with the slot in it for pulley adjustment. see original thing.
I then redesigned the motor mount again to take out as much of the flat as I could. here are the results of those redesigns. the bearing now hits the end of its travels like PRUSA intended.
0.1mm or 0.2mm doesn't matter
your favorite brand of PETG PETG