My QU-BD Two-Up printer came without these two important X / Y axis timing pulleys. These are part QQ - 12-HTD3-05.
So I figured a temporary replacement could be made while I wait 3 weeks for them to ship me the original bits.
This was made from droftart's excellent timing gear generator SCAD file, here http://www.thingiverse.com/thing:16627
My modifications to the SCAD file include adding a key to lock it to the spindle shaft. My first upload of this file used bolts to lock it against the shaft, but there were clearance issues when assembling the Two Up, so I added the keyed shaft and superglued it to the motor spindle. It now works very well, holding up as well as the original parts and allowing no slack or play when changing direction.
Pulley specs are:
12 Tooth Pulley
6mm Belt Width
3mm Spacing HTD Tooth Profile
5mm Bore Diameter (For NEMA 17 Motors)
Flange on both ends to ensure belt doesn't slip off.
I make stuff