system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do power tools (especially ones that need high torque) often employ a motor spinning at a ridiculous speed and then a deep reduction, instead of a motor spinning directly at the tool's speed and higher torque?
gpt
An electric motor works by having magnets and electromagnets arranged around the axle, which attract and repel each other in succession to spin the motor. To get high torque you need to have very strong magnets and/or very strong electromagnets. Increasing the strength of the magnets and/or electromagnets by 20 times you will have a motor which is 20 times as big and heavy.

On the other hand, electric motors can naturally spin at very high rates. A reduction gear which increases torque by 20 times (and reduces RPM) will be smaller and lighter than the motor you attach it to, making this a far better solution to get high torque at low RPM than building a bigger motor would be.