Summary This is my (hopefully improved) Y-Axis Idler Pulley & Gear for Solidoodle2. It's all 3D printed, the only extra parts are the 2 ball bearings and a piece of 2.5mm carbon fiber (or steel) to strengthen the (fully printed) toothed belt pulley. It's the absolute minimum size needed to do the job properly, and my Print Head carriage doesn't crash into the Y-idler bearing assembly anymore, plus it's really quiet and should never wear out. Also, the inside is curved, so the toothed belt just slides in when everything is fully assembled The only extra mod is to drill out the (IMHO very stupidly designed) screw mount to 3mm, so the screw is attached from the outside, a great improvement if one isn't triple jointed :-) Ball bearing details bearingDia = 13 ; // bearing Dia (mm) bearingWd = 5 ; // actual width of bearing (mm) bearingIn = 4 ; // inside dia of bearing (mm)