Injection-Molded Sprocket Set 8T Futaba

via Pololu
$18.34
SKU PL-358

These 8-tooth, injection-molded sprockets are made to work with the rugged miniature tank tracks. This set comes with four sprockets made from sturdy, black ABS plastic: two sprockets for mounting on servos with Futaba-compatible splines, such as those on the SpringRC SM-S4303R and Power HD AR-3606HB continuous rotation servos, and two idler sprockets with 1/4″ holes that you can mount using shoulder bolts.

The diameter of the sprocket by itself is 1.5″. Once the rugged miniature tank tracks are around the sprocket, the total diameter is roughly 1.77″.

18-link chains of the miniature tank tracks in assorted colors with 8-tooth sprocket pairs.