Prusa MK3 Y-Axis Belt Tensioner for Gates 20T Idler with 5mm Bore

thingiverse

Y-Axis belt tensioner for Prusa MK3. This is for a 20T Gates Idler with a 5mm bore. It's loosely based on MattyVee's excellent design, https://www.thingiverse.com/thing:2786671. Items you'll need for this: (1) Gates 20T idler with a 5mm bore (1) 4.95'ish mm diameter shaft at 24mm long (opening is 24.5mm so 24mm works just fine (2) M3 x 20mm socket head cap screws (1) for the pivot and (1) for the tensioner (2) M3 x 8mm socket head cap screws to mount tensioner to the frame (4) M3 hex nuts, can use flats or Nylock but I see no reason to use Nylock nuts I included (2) .4mm washers to center the idler, not necessary but I prefer them. Note the nuts are a tight fit, I do this to keep them from falling out but be prepared to put some effort into seating them, except for the tensioning nut slot. Print without supports and as oriented in the files, except the washers need to be properly oriented I printed on standard Prusa settings, 2 perimeters, 20% infill and all works fine, feel free to print as you see fit.