These wheels consist of 12 durable, gray urethane rubber rollers. Each roller has a polycarbonate core, and 2 high load steel bushings. Bushings ride on brass tubes, which are captured between aluminum side plates with an #10-32 screw.
These roller can be purchased individually, or in sets of 12. Wheels can be purchased in a set of 4, or individually. Wheels are sold without hubs, sprockets, or bearings.
These wheels are being set up in two ways:
Sprocket-Driven
If driven by a sprocket, these parts are needed:
Flanged ball bearings with 1.125" od: AndyMark offers a 3/8" id version (am-0573), and a 1/2" id version (am-0030)
One 550 sprocket spacer is needed to space the sprocket out away from the wheel, so the chain clears the edge of the wheel.
A sprocket with a bolt hole circle of 1.875" diameter mounts to the wheels' interior screws.
Shaft-Driven
If the wheel is being driven directly by a rotating shaft, then use an AndyMark hub, like the 500 Key Hub to mount directly to the shaft. Also, some spacers and a 1/4-20 screw and a 1/4" washer to cap the end of the shaft will hold the hub (and wheel) onto the shaft.
Load Capacity (each wheel)
Original 8" Wheel (am-0083): 180 pounds 8" Mecanum HD Wheel (am-2118): 500 pounds