These universal mounting hubs are designed to work with most 5 mm diameter shafts, including round shafts and “D” shafts, such as those on our stepper motors. Each of the two included hubs has four mounting holes for #4-40 screws (not included), letting you mount custom wheels or mechanisms to your motors. The two included #4-40 hex set screws (one for each hub) allow secure coupling of shaft to hub, and a 0.05″ hex wrench (often the smallest size in SAE Allen wrench sets) 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 most of our stepper motors (the ones with 5 mm shafts), and they also work with 60 mm, 70 mm, 80 mm, and 90 mm Pololu wheels (excluding the Multi-Hub versions; see the individual wheel pages for compatibility details).