K40 y-axis belt tensioner and pulley replacement

thingiverse

Replacement y-axis belt tensioners for the k40 lasers. I really didn't like how poorly designed the stock (RH side in the picture) were. The pulleys were printed in resin but can be printed in FDM and will need some clean up to get them to work. 5mm nut will drop into the tensioner. I suggest adding a couple drops of super glue to keep it in place. The bearings press fit into the pulley and should sit about 1mm under the lip. To assemble, place the tensioner through the frame. Put the belt around the pulley insert the pulley with belt into the tensioner and place the 5mm bolt through. Use a pair of needle nose or open end wrench to hold the nut and make sure not to tighten too much. If the pulley doesn't easily spin the bolt is too tight. If the bolt has a bit of movement that is good. Add a nut and washer to the remaining bolt thread it into the tensioner where the nut is superglued, adjust the belt and tighten up the jam nut. You're all set. Hardware: 2 - 5mm nut (for jam nut to adjust pulley) 2 - 5mm washers (for jam nut to adjust pulley) 2 - 5mm lock nut (for holding the bolt that goes through the pulley) 2 - 5mm washers (for jam nut to adjust pulley) 4 - 5mm bolts (about 20mm) (sorry I cant remember exact sizes) 4 - 5x11x4mm Bearings. (used in Traxxas RC cars)