1. Change the motors of different diameter shafts. 2. Change belt pulleys with different speeds and reduce the purchase of new motors or pulleys to maintain existing components and speed/power requirements. 3. Adapt the larger wheel hole to the small shaft and work with the pneumatic crankshaft to expand the diameter of the crank to accommodate pulleys, gearboxes, etc. 4. Material: Iron 5. Surface treatment: galvanized
