1. Create a skecth as show on Front Plane.
2. Revolve sketch, 360 degree on top sketched line . OK.
3. Create circle skecth, on right plane 4.8in , extrude 2in OK.
4. Insert sketch on edge wheel face, skecth for arm hole , extruded cut , through all, OK.
5. Add fillet R0.5in inner ...