Pololu Universal Aluminum Mounting Hub for 1/4″ Shaft, M3 Holes (2-Pack)

These universal aluminum mounting hubs allow you to mount custom wheels and mechanisms to 1/4 inch
diameter motor shafts. The set includes two hubs, four M3 set screws
for securing the hubs to motor shafts, and one 1.5 mm Allen wrench for
use with the set screws. Each hub has six threaded mounting holes for
M3 screws (not included).

These universal mounting hubs are designed to work with most
0.250 inch (6.35 mm) shafts, including round shafts and “D” shafts,
such as those on our NEMA 23 stepper motors. Each of the two included hubs has six mounting holes for M3 screws
(not included), letting you mount custom wheels or mechanisms to your
motors. The four included M3 hex set screws (two 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.

These hubs will work with our NEMA 23 stepper motors, and they also work with 80 mm and 90 mm Pololu wheels.