The frame and support base could be made of the usual materials recommended for the device in Figures 1, 3, etc. described earlier – thin steel or aluminium sheet. The rollers are made of steel or PVC. Rolled aluminium could also be used. The rope is (standard) steel or some other material, like nylon, for example. The gears are steel or PVC. The scale is aluminium or steel and aluminium or PVC foil could also be used.