These Pololu universal aluminium mounting hubs allow you to mount custom wheels and mechanisms to 4mmdiameter motor shafts

The set includes two hubs, two #4-40 set screws for securing the hubs to motor shafts, and one0.05 Allen wrenchfor use with the set screws. Each hub has four threaded mounting holes for #4-40screws(not included).

We have an assortment of universal mounting hubs available, spanning several shaft sizes and featuring mounting holes threaded for metric or imperial screws. These universal mounting hubs are designed to work with most 4mm diameter shafts, including round shafts and D shafts.

Each of the two included hubs has four mounting holes for #4-40screws(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 a0.05 hex wrench(often the smallest size in SAE Allen wrench sets) is included for use with the set screws.

The product images show a hub with Pololus25:1 metal gearmotor 20Dx44Land aPololu 20D metal gearmotor bracket. These hubs will work with any 20D metal gearmotor or25D metal gearmotor, and they also work with 60mm, 70mm, 80mm, and 90mmPololu wheels(excluding theMulti-Hub versions; see the individual wheel pages for compatibility details).

Specifications

• Size: 19 mm diameter 5 mm thick
• Weight: 3.2g*
• Shaft diameter: 4mm
• Mounting hole size: #4-40**

*For a single hub only (without set screw)
**This is also the size of the set screw