Engineers can use planetary gears to increase or decrease both speed and torque, and to do so in a small, compact space. Planetary gears can supply high levels of torque and high-speed reduction.

As gears get smaller and spin faster, they generate more heat. Sometimes that heat proves too much for petroleum-based lubricants, which is why most OEMs use synthetic lubricants to handle the ...

So, let’s start there. Gears work on the principle of leverage, where it’s easier to turn something with a long handle, but harder to spin it at high speed. You can spin a top with your finger ...

[Maciej Nowak] demonstrates just how to produce your own gears with a homemade cutting tool. The cutting tool for the job is an M16 machine tap, chosen for the smaller flutes compared to a hand tap.