This is a robot drive wheel we had made specifically for us. It does not have a bearing. It is 6 inches in diameter and 2 inches wide. It's a solid foam core with rubber treads and outer layer. The steel rim is painted black with a 4 bolt pattern so you can easily mount it to a flanged hub.
This is our prebuilt HD2 Mastiff robot with a 6 axis robotic manipulator arm. This robot is loaded with all the options and is ready to ship.
Steel Machine Key 3/16" x 3/16", 3/4" long. These keys are economical with high strength and will fit 3/16" keyways.