Tamiya˙s 8-speed mini motor gearbox features a more compact 030-form-factor motor driving a single gear train that can be assembled to have one of eight gear ratios: 7.5:1 9.5:1 15.7:1 19.9:1 32.9:1 41.8:1 79.1:1 or 87.8:1.
The mini-motor gearbox kit from Tamiya makes it easy to get a small robot or plastic model moving. The kit includes one motor and all the gears and parts to build any of the eight possible gear ratio configurations: 7.5:1 9.5:1 15.7:1 19.9:1 32.9:1 41.8:1 79.1:1 or 87.8:1. The eight gear ratio options give you the flexibility to choose the best speed and torque for your project. There are two possible output axle locations (only one output location is possible for any given ratio).
The kit includes step-by-step illustrated instructions in both Japanese and English. A scanned copy of the instructions is available on the Pictures tab. The kit can be built with just a screwdriver but the instructions recommend having side cutters tweezers and a modeling knife on hand. The gearbox kit˙s motor has a 030 form factor that is smaller than the Tamiya gearboxes that use the Mabuchi FA-130 motor.