I found this on Thingiverse, and thought I should upload it here.

The original file was created by sutekh, but it was broken, so Rickmcolorado repaired it. Here's the original post: 

“A friend with an Apprentice needed a bulked up motor mount to replace the much more fragile stock part. This is an exact fit compared to the OEM part (same hole paterns and spacing, same motor standoff length and angle, etc.), but with thicker bracing and a few of the superfluous holes deleted.”

And here are the printing parameters from Rickmcolorado:

"Printer brand:

Prusa

• Printer:

i3 MK2S

• Rafts:

No

• Supports:

Yes

• Resolution:

.2mm

• Infill:

100%"

I've included a .zip of the .gcode because for some reason Printables doesn't like it as a .gcode. It prints fine.