3 : 1 · six planets
Module 1 · 20° · spur
Six planets round a big sun: a striking demo and a strong, low ratio.

The classic printed gear bearing: herringbone teeth hold it together round five planets.
Using the CheapCADTools connector, design a 3.6 : 1 planetary gear set in Planetary Gear Designer: module 1.5 mm, 20° pressure angle, herringbone teeth, a 25-tooth sun, 20-tooth planets and a 65-tooth ring, five planets, a profile shift of 0.2 on the planets, face width 15 mm. The sun: an 8 mm bore. The carrier: a one-sided (cantilevered) carrier. The carrier's output: an 8 mm bore. Check the design, apply any Auto-fix it suggests, then export every part (the sun, a planet, the ring and the carrier) as STEP and STL and give me the download link.
Paste it into Claude, ChatGPT or any AI app with the CheapCADTools connector, and it designs this planetary set with you, checks it and hands you the files. How to connect your AI.
The link opens the whole set in the Planetary Gear Designer's 3D view. Change the teeth, the number of planets or stages, which member is held, the carrier, bores or hubs, then download STL, STEP or the carrier's DXF and SVG.
Module 1 · 20° · spur
Six planets round a big sun: a striking demo and a strong, low ratio.
Module 2 · 20° · herringbone
Carrier held, sun in, ring out: the output reverses, as in a turbofan's gearbox.
Module 2 · 20° · herringbone
Sun held, carrier in, ring out: the ring overruns the input, like a car's overdrive.
Module 1 · 20° · herringbone
Eight planets fill the ring, the most the app takes, still clear of each other.