Wheel and Axle

13 cm diameter molded wheel contains 4 grooves of different diameters in the ratios 1, 3, 5 & 7. The grooves are wide and flat bottomed ensuring an exact diameter for each groove, each comes with a small hole to retain the cord. The back of the wheel is hollow to minimize the mass and inertia. Wheel is attached to a 14 cm long rod.