4 : 1
4 : 1 · NEMA 17 gearbox
Module 1 · 20° · spur
A one-stage 4 : 1 reducer for a NEMA 17 stepper: 5 mm D-flat sun, three planets, 8 mm output.
Samples · Planetary Gear Designer
31 planetary gear sets, ready to open
Stepper gearboxes, robot joints, FRC hex-shaft sets, desk toys and industrial reducers, one to three stages. Each opens in the Planetary Gear Designer with the sun, planets, ring and carrier assembled, in 3D, every setting in place and ready to change. Looking for something else? See the timing pulley, sprocket, gear, worm gear and bevel gear samples.
Use
5 : 1
5 : 1 · NEMA 17, herringbone
Module 1 · 20° · herringbone
5 : 1 in one stage; herringbone teeth run quietly and keep the planets in line.
16 : 1
16 : 1 · two stages
Module 1 · 20° · spur
Two stacked 4 : 1 stages: each carrier prints with the next stage's sun.
25 : 1
25 : 1 · two 5 : 1 stages
Module 1 · 20° · herringbone
Two 5 : 1 stages for slow, strong stepper output.
64 : 1
64 : 1 · three stages
Module 1 · 20° · spur
Three 4 : 1 stages stacked: 64 : 1 for turntables, telescopes and slow axes.
4 : 1
4 : 1 · compact NEMA 17, 60 mm
Module 1 · 20° · herringbone
A smaller 4 : 1: 15-tooth planets, shifted (x 0.2) so the ring's tips clear them; 60 mm across.
5 : 1
5 : 1 · compact NEMA 17, 51 mm
Module 0.8 · 20° · herringbone
5 : 1 at module 0.8 with a shifted 12-tooth sun and shifted planets: the smallest clean set, 51 mm across.
125 : 1
125 : 1 · three 5 : 1 stages
Module 1 · 20° · herringbone
Three compact 5 : 1 stages, 63 mm across, for solar trackers, telescope mounts and slow turntables.
5 : 1
5 : 1 · NEMA 23 gearbox
Module 1.5 · 20° · herringbone
A module 1.5 stage for a NEMA 23 on a ¼" D-flat shaft.
6 : 1
6 : 1 · quasi-direct-drive actuator
Module 1 · 20° · herringbone
The low-ratio stage legged robots put behind a brushless motor; flanged ring, six M3 bolts.
7 : 1
7 : 1 · one-stage actuator
Module 1 · 20° · herringbone
7 : 1 in one stage: a small sun and big planets, still back-drivable.
36 : 1
36 : 1 · robot arm joint
Module 1 · 20° · herringbone
Two 6 : 1 stages for a printed robot arm's shoulder or elbow.
4 : 1
4 : 1 · slim wrist, one-sided carrier
Module 1 · 20° · spur
A short 4 : 1 with a single-sided carrier and four planets, for a robot wrist.
5 : 1
5 : 1 · planets on ball bearings
Module 1.5 · 20° · herringbone
Each planet runs on a 625 ball bearing for long life under load.
4 : 1
4 : 1 · 32 DP, ½" hex output
32 DP · 20° · spur
An FRC-style stage: 8 mm keyed motor shaft in, ½" hex out.
9 : 1
9 : 1 · two 3 : 1 stages, hex out
32 DP · 20° · spur
Two 3 : 1 stages, 32 DP, ending in a ½" hex output.
5 : 1
3 : 1
3 : 1 · 32 DP, hex out
32 DP · 20° · spur
The 3 : 1 stage, a big sun and small planets, 8 mm keyed in, ½" hex out.
7 : 1
7 : 1 · 32 DP, hex out
32 DP · 20° · spur
7 : 1 in one stage: an 18-tooth sun, the smallest that takes the 8 mm keyed shaft, ½" hex out.
3.6 : 1
Herringbone gear bearing · 5 planets
Module 1.5 · 20° · herringbone
The classic printed gear bearing: herringbone teeth hold it together round five planets.
3 : 1
3 : 1 · six planets
Module 1 · 20° · spur
Six planets round a big sun: a striking demo and a strong, low ratio.
3.33 : 1
Star arrangement · ring turns backwards
Module 2 · 20° · herringbone
Carrier held, sun in, ring out: the output reverses, as in a turbofan's gearbox.
1 : 1.3
Solar arrangement · overdrive
Module 2 · 20° · herringbone
Sun held, carrier in, ring out: the ring overruns the input, like a car's overdrive.
2.83 : 1
8 planets · 2.83 : 1
Module 1 · 20° · herringbone
Eight planets fill the ring, the most the app takes, still clear of each other.
1 : 5
1 : 5 speed-up · wind turbine
Module 1.5 · 20° · herringbone
Ring held, carrier in, sun out: the sun turns five times as fast, to spin a small generator.
5 : 1
5 : 1 · module 2, keyed, 6000 bearings
Module 2 · 20° · spur
A metal-ready 5 : 1: keyed shafts, planets on 6000 bearings, a flanged ring with eight M5 bolts.
4 : 1
10.24 : 1
10.24 : 1 · two 3.2 : 1 stages
Module 1 · 20° · spur
Two 3.2 : 1 stages with four planets each: about 10 : 1 in a short housing.
6 : 1
6 : 1 · 25° pressure angle
Module 2 · 25° · spur
25° teeth: a 14-tooth sun without undercut and stronger roots, 6 : 1.
4 : 1
6 : 1
6 : 1 · module 3 winch drive
Module 3 · 20° · spur
A big 6 : 1 for a winch or drum: module 3, a 300 mm ring with twelve M5 bolts.
Designing is free; the STL, STEP and the carrier's DXF and SVG download from the app for tokens. Each set was checked in the Planetary Gear Designer and opens with no warnings.