This Electric motor has a 90 deg gear head for better use of space allocation. This would be ideal for turning wheels on a robot where the wheels are required to have very high torque. The speed on these are just about right for a medium speed robot but with enough torque to get up the steepest hills.The shaft has a 6mm dia and works great with our hubs or pulleys Links below. The flat on the Shaft is what you will tighten the set screw to in order to prevent the pulley or hub from rotating
https://www.firgelliauto.com/products/micro-motor-pulley
https://www.firgelliauto.com/search?q=hub
Specifications
Torque: 6KG-CM
RPM: 24
Shaft Diameter: 6mm (.236”)
Height: 27mm
Length: 77mm
Width: 32mm