Pololu item 2682: 12mm Hex Wheel Adapter for 3mm Shaft (2-Pack)

Description

These light-weight aluminum shaft adapters convert a typical motor output shaft into a 12 mm hex shaft that is compatible with many common hobby RC wheels, such as the Dagu Wild Thumper Wheels. The side of each adapter that mounts to the wheel contains a hole tapped for M4 screws, and the other side of the adapter mounts to a motor shaft with two M3 set screws. This set includes a pair of adapters, two 8 mm M4 screws, four M3 set screws, and one 1.5 mm Allen wrench for use with the set screws.