These universal mounting hubs are designed to work with most 3 mm diameter shafts, including round shafts, “D” shafts, and Tamiya’s 3 mm hexagonal shafts. Each of the two included hubs has four mounting holes for M3 screws (not included), letting you mount custom wheels or mechanisms to your motors. The two included M3 hex set screws (one for each hub) allow secure coupling of shaft to hub, and a 1.5 mm hex wrench is included for use with the set screws. A dimension diagram of the hub is available under the resources tab.
The picture to the right shows a hub with one of Pololu’s mini metal gearmotors and a Pololu mini metal gearmotor bracket. These hubs will work with any Pololu mini/15.5D mm metal gearmotor or micro metal gearmotor, and they also work with 60 mm, 70 mm, 80 mm, and 90 mm Pololu wheels.