I don't like that the original Prusa MK3 uses one of the y axis bearings for the end stop detection. This means that the bearing gets rammed into the rod holder everytime the printer homes his position. This puts an off center load on the y axis.
Since I'm using pekcitron's great Bear Upgrade I have modified his y motor mount to act as the y axis endstop for homing. Now the y belt holder ramms in to the y motor mount. This removes the stress on the bearing and results in a centered load. Thank you very much pekcitron for making your design open source which makes such modifications very easy!
I'm using this in conjunction with zbrozek's y-belt holder and tensioner. Which is also a great design and is working flawless.
With Source file
I have added the .f3d source file as I hope more people would add source files to their things. Often I want to modify a thing and having only the .stl file it's more cumbersome than it should be in my opinion. So I don't want anybody to get frustrated when they want to modify the design.
0,2 mm height and 0,4 mm nozzle
This design also uses selective infill structures like the original design.
So slice with Slic3r and the same settings, which pekcitron advises for his original motor mount.
Motor pulley orientation
I have mounted the pulley on the Y motor the same way as it is on the X motor (grub screw away from the motor). I wanted the beld as close as possible to the motor to minimise leverage on the shaft.
Failure during the design process and about the pictures above
The pictures are showing my prototype, wich was originally ment to be screwed to the motor with all four screws.
But this proves not to be working, since the arm which holds the fourth screw is to far in front and the y belt holder will crash into it and not against the intendet endstop surface.
So i had to cut off the part with the fourth screw and the result is a working design, which is the stl and fusion file I uploaded.
I actually using my prototype since it's also working flawless and reprinting is kinda a waste of plastic.