Four-wheel Drive Children Scientific Experiment106Pcs Plastic Motor Gear Rack Pulley Worm Single Double Gearbox for DIY Robot Toys Car Ferry Model

Introduction:
Contains a variety of different types of gear, all can be consistent with each other, modulus 0.5, the hole were 1.9mm, 2.05 (2.0) mm, 2.4 (2.55) mm, 2.9 (3) mm and so on. Also includes hexagonal gears, racks, pulleys, belts, axles and other diy accessories.
Gear diameter formula: gear diameter (addendum circle) = (number of teeth +2) * modulus