Customiser: YAPI - Yet Another Pulley for Idlers (aka "Yay, no more soot")

thingiverse

I recently combined several parts to minimize the amount of black dust and soot resulting from Y belt abrasion on my Chinese Prusa i3 Pro B clone's idler. Clear signs of belt wear are visible in an enlarged photo. Divided into two or three parts, depending on whether bearings are used, overhangs are entirely eliminated, making this design easily printable. This part can be customized to work with or without ball bearings; however, I'm concerned that without bearings, my printer would eventually produce blue PLA dust instead of black belt soot. It is now possible to set values that don't make sense when combined - only a few variables are protected against such combinations. Large bearings can also be a source of amusement if desired. Pre-set values yield an X axis idler pulley for the Prusa i3 Pro B, utilizing MR74 bearings (4x7x2) and slightly increasing barrel diameter to keep the X drive belt just a little further apart - the default "pulley" caused the running end of the belt to touch the channel leading it through the X carriage and rub against the pulley holding bracket. Due to increased barrel diameter, I had to replace the screw holding the X idler with one having a flatter head or the belt would touch the screw head. Finding a suitable replacement was not difficult as the original screw head had a high profile. Two weeks after installation, I can conclude that my printer's black soot and belt wear problem has been resolved - there is no sign of newly worn-off belt material now.