| This product range comprises turned brass pulleys or sheave wheels and specially made Chloroprene rubber (CR) drive belts. The belts are square in cross section and are closely related to those found in mini voice recorders of the tape variety and many other small mechanisms in audio and video machines. They will not take on a 'set' (like rubber bands do) if left stretched permanently for many years so long as the stretch no more than about 10%. At present I have 5.5mm, 6.5mm, 7.5mm, 10mm & 12mm ID belts which can be used to make up, for example, a 3.5:1 reduction when used with a 1.1mm or 1.2mm root pulley and a 5mm root pulley. The full range of available pulley root dimension is 1.1mm, 1.2mm, 1.7mm, 3mm, 5mm, 7mm & 9mm. The pulleys' grooves are Vee shaped and the 'root' is the minimum radius at the bottom of the Vee. The pulley OD is generally 1mm larger so for example the 5mm root pulley is only 6mm OD and the overall volume taken up by two pulleys and a belt is smaller than for spur gears or the reduction better. The 1.1mm root pulley is supplied with a 0.8mm centre hole to match my micro motors and the 1.2mm with a 1mm centre hole for my midi and mini motors. The other pulleys have 1.5mm diameter centre hole to match standard shafting, wheelsets and larger motors like the Mashima range. All five sizes of pulley and five sizes of belt are currently available in my online shop |
