PLANS are for a 2:1 gearbox, but after we thought about it, why not make it 11 speeds AND driven by a servo motor. Obviously only one mechanical speed at a time, but still capable of 11 different mechanical speeds. The original need was for a 2:1 reduction to lower the speed on a NEMA 17 electic servo motor. Most gearboxes have a fixed Pinion and Gear and have been designed to only hold those two gears. Ours has room for tooth counts from 40 to 20. Combining them on the same center distance gives 10 different speeds. The 30:30 ratio is 1.000 which is useful as the shaft rotation will be reversed.
THIS KIT REQUIRES MACHINING ALUMINUM AND STEEL - If you can mill, drill, bore and tap on a mill, and turn and groove on a lathe you can do this.
THIS KIT includes a build sheet including specifications for all of the component parts
The kit calls for 6061 Aluminum for the gearbox, 4 ball bearings help the 8mm shafts spin the gears with very little friction. Two spur gears a 40T and a 20T are used for the 2:1 ratio.
Encoder - A pocket on one side houses an encoder for measurement of RPM. If you are handy with electronics and reading the uadrature signal, you can read the RMP of the system.
Low Friction - The open bearings, use of grease, and lack of seals keeps this one spinning with very low friction.