56 mm Set-Screw N20 Wheel
A 56 mm OD x 13 mm wide drive wheel for the 3 mm D-shaft of an N20 gearmotor, part of the 'N20 4WD Skid-Steer Rover Base' kit (print 4). It has a 3.3 mm bore, an M3 set screw with a captured M3 nut in a drop-in slot, a 4 mm access hole in the rim for the hex key, and two 3 x 1.5 mm tread grooves for rubber bands or O-rings. You can take the wheel off and put it back on as often as you like without the bore wearing loose, which is how press-fit hubs fail.
robotics kit n20 wheel