Timing Belt Y MXL, Printrbot Simple V2

thingiverse

This is for the Simple V2 w/o String tension ordered BEFORE 10/23/2013. For models WITH string tension see http://www.thingiverse.com/thing:220484 The motor mount and tie bar are identical on both MXL designs. Having difficulty keeping consistent traction with the string drive on my Simple Y axis, I set out to design a more positive drive. Design parameters were: Timing belt drive "Bolt on" solution, no modification of machine required Ability to revert back to string drive if necessary This has been running almost non-stop for over a week now without any issues, so it is time to share with the group. Enjoy. As always comments, concerns, and suggestions for improvements are not only welcome but encouraged. Update 1: Be careful not to over tighten the belt. In the gallery is a picture of my "quick fix" after getting a little wrench happy. I will draw up a little link bar that can be installed outside the drive gear to tie the bearings together very soon. Screws shown are M3 x 22mm. Update 2: I have added a couple files: "Bearing Tie Bar" to allow for higher belt tension without deflecting bearings out of alignment. It has been designed for M3x22 screws, but M3x20 should work as long as you don't have too much debris in the hex nut socket. "Motor Plate Option A" to completely remove the captive nut and allow for more strength of the bearing supports. There is no axial load on the bolts so there should be no problems with simply threading into the printed part. Updated drawing to show link bar. Instructions Notes: The assembly of the timing belt pulley and bearings is close, but possible. The bearings must be centered on the pulley I had to lightly sand the upper edge of the wooden slot so the set-screw on the timing belt pulley would not rub. The pulley sits on the end of the motor shaft. Less than ideal, but I haven't had any issues thus far. 5mm drill bit used was from McMaster Carr 28255A39