This is my design for the conversion from a belt driven drive to direct drive for the Y-Axis on my Solidoodle 3. Items needed: (4) 608ZZ bearings (1) 8mm shaft (1) 5mm to 8mm coupling M3 screws and nuts, I had M3x25's on hand so that's what I used. I was also upgrading to GT2 at the same time, so I had 8mm diameter pulleys as well. I'm satisfied with it so far. The frame actually flexes quite a bit, but my circles are circles, so the goal was accomplished. It might help to have a spider coupling instead of the helical that I used. This is a fairly simple modification to do. The motor mount uses the existing holes for the old Y motor location, which means it has a good range of adjustment for aligning everything. The two interior pillow blocks and the side block I drilled holes to mount them. How you line everything up is up to you, I measured some and eyeballed some. Some of the files I have updated just a tad to make them a bit more aesthetic than my purely functional ones pictured. Constructive criticisms, comments, and questions are welcome.