The gear ratios allow you to apply more torque without needing a long handle. As you may have guessed, the internal arrangement is a planetary gear drive. You might consider if you want to print ...

In those mechanisms, a high-torque, low backlash gearbox might be just the thing, and a 3D printable split planetary harmonic ... the stepper drives a sun gear with two planet gears orbiting ...

Stargazers across the country have their telescopes at the ready to capture a rare planetary event next month (February).