How to Attach Shafts to Motors

Hi all,

Rookie mentor here.

We’ve successfully attached our wheels to the KOP bot, but I’m having trouble figuring out how to attach our motors to shafts for different mechanisms. After a long search of AndyMark, it seems that most motors come with an output shaft of 8mm or 10mm with a keyway. But, how do I easily convert this output to a 1/2" or 3/8" hex shaft for example? Any simple solutions?

I realize this question may be super simplistic for many of the veterans, but I can’t figure it out. Any links to products would be very helpful. Thank you!


This useful adapter will change a cim shaft to a 1/2 inch hex shaft. This is useful for attaching pulleys or gears. :slight_smile:

CIM motors have the largest shafts of any motors used in FRC (8mm keyed) the vex adapter posted above is an easy way to convert it to 1/2in hex.

If you want to use non-CIM motors, versaplanetary gearboxes are the easiest way to reduce the speed (and increase torque) while also having many more output shaft options (also compatible with CIM motors). Unfortunately kinda pricey. http://www.vexrobotics.com/versaplanetary.html

If you want to use a gear reduction, then many gearboxes on AM and VEXPro have gears compatible with the CIM gear. These gearboxes then output to 1/2" hex or keyed round shafts, which can be coupled to sprockets, wheels, etc.

If you’d like to use direct drive, get hubs. Lots of hubs. These are compatible with the KoP wheels, sprockets, belts, etc. We generally buy these hubs and then build our own custom mounts for them. Sometimes we connect 2 hubs together (same bolt pattern) to convert a 10mm shaft to a 1/2" shaft (for example).

http://www.andymark.com/Hubs-s/215.htm