A 6 mm steel shaft is mounted on stand post with nylon or metal bearings. One end carries an aluminium V pulley 56 mm dia and other, over hanging end is fitted with a cord anchoring. For showing the conversion from electrical energy via mechanical to potential energy by winding up a weight on a cord. One end of the 6 mm steel shaft carries an aluminium 'V' pulley 56 mm diameter and the other end is fitted with a cord anchoring collar. Size 10 x 20 cm