Kingroon KP3S X Axis Belt Tensioner 16T Idler Pully Spanner

thingiverse

The original is a great design and fits the original printer idler perfectly. This remix extends the spanner (where the idler is mounted) with two things: It has different mounting tolerances and holes to allow a 3mm inner bore GT2 idler (both smooth and 16 toothed) instead of the original 4mm inner bore flanged bearings. The screw used for mounting the idler also is not screwed directly into the spanner plastic anymore, but rather uses two M3 threaded heat-sunk inserts to rigidly mount it. This means the screw does not rub into the plastic anymore when tuning slightly. It allows to countersink a M4 nut into the spanner in order not to have the pulling screw rotate freely. I had the problem where turning the adjustment knob would lead to the pullling M4 screw rotating due to too high friction. When placing the nut below the screw-head, this is no problem when tightening at least (loosening could still show the same problem, though).