DIY Miniature Belt Machine Driving Wheel Mini Small Transmission Main Wheel Motor Spindle Belt Power Wheel Driven WheelThe caliper measures the diameter of the motor shaft to about a millimeters, after which selects the shaft hole of the same length because the motor shaft. This abrasive belt wheel is barely suitable for the use of the optical shaft and the D-shaped shaft, now not compatible for the threaded shaft and the shaft flower and the large-area scraping motor shaft. This belt grinder pressure wheel can be used for flat groove pulleys.