Heads up: many models on this page are AI-generated or uploaded untested. They may be misconfigured for the intended application — check the dimensions and tolerances, and verify or edit the model before printing or relying on it.*
Twin 624 Track Idler Sprocket
The free-running front idler (print 2) for the 'N20 Twin-Track Mini Tank Chassis' kit. It has the same 12-tooth, 12 mm-pitch profile as the drive sprocket: a Ø46 x 10 mm disc with teeth reaching Ø51.2. Its 18 mm hub holds two 624 bearings (4 x 13 x 5 mm) in 13.05 mm press-fit seats, one at each end, with a 10 mm lip between them. The pair spins on the hull's slotted M4x30 bolt axle and stays stiffer and better aligned than a single-bearing idler.
12T Track Drive Sprocket
A 12-tooth, 12 mm-pitch drive sprocket (Ø51.2 mm over the teeth, 10 mm disc) for the 'N20 Twin-Track Mini Tank Chassis' kit. It fits directly onto an N20 gearmotor's 3 mm D-shaft with a 3.2 mm blind bore in a 16 mm hub that is 12.5 mm long. An M3 grub screw and a captured M3 hex nut lock it to the shaft, so no separate hub or plate stack is needed. The teeth have a 45° underside chamfer so they print without supports, and they mesh with the kit's print-in-place track links.