18 : 60
18T : 60T · 20 DP on ½" hex
20 DP · 20°
A 3.33 : 1 robot gearbox stage: 20 DP gears on ½" hex shafts, held by retaining rings.
Samples · Gear Designer
25 gear sets, ready to open
Robot gearboxes, 3D-printed drives, industrial spur, helical and herringbone pairs, inch diametral-pitch gears, ring gears and racks. Each opens in the Gear Designer with both parts in mesh, in 3D, every setting in place and ready to change. Looking for pulleys or chain? See the timing pulley samples and the sprocket samples, or the worm gear samples.
Use
14 : 84
14T : 84T · 6 : 1 arm stage
20 DP · 20°
A 6 : 1 arm reduction: a pinion on an 8 mm keyed motor shaft into an 84-tooth, six-spoke gear on ½" hex.
16 : 48
16T : 48T · herringbone, 8 mm D-flat
module 1.5 · 20° · herringbone 30°
Quiet, thrust-free herringbone gears for a robot joint: 3 : 1 on 8 mm D-flat shafts.
15 : 45
15T : 45T · NEMA 17 reducer
module 1 · 20°
A 3 : 1 printed reduction for a NEMA 17 stepper: the pinion on its 5 mm D-flat shaft.
16 : 80
16T : 80T · 5 : 1 extruder
module 1 · 20°
An extruder's 5 : 1 reduction: a 16-tooth pinion, profile-shifted so it isn't undercut.
13 : 39
13T : 39T · printed herringbone
module 2 · 20° · herringbone 30°
The classic printable herringbone pair: self-centring, 3 : 1, spoked.
20 : 40
20T : 40T · hubs, nuts and inserts
module 1.5 · 20°
Two ways to hold a printed gear: captured nuts on the pinion, heat-set inserts on the gear.
20 : 60
20T : 60T · module 3, keyed
module 3 · 20°
A 3 : 1 module 3 spur pair on DIN 6885 keyed shafts, a hub on each gear.
18 : 54
18T : 54T · 20° helical
module 2 · 20° · helical 20°
A quiet 3 : 1 helical pair, 20° helix, keyed bores; the teeth overlap for a smooth mesh.
17 : 34
17T : 34T · ISO 14 splines, rack B
module 4 · 20° · ISO 53 rack B
A high-torque module 4 pair on ISO 14 splined shafts, cut to ISO 53 basic rack B.
24 : 48
24T : 48T · helical on ISO 4156 splines
module 2.5 · 20° · helical 15°
A 2 : 1 helical pair on involute (ISO 4156) splines, retaining rings over splined washers.
15 : 45
15T : 45T · 25° pressure angle
module 3 · 25°
25° teeth: stronger roots and a 15-tooth pinion that needs no profile shift.
24 : 36
24T : 36T · 20° stub teeth
module 2 · 20° stub
Short, stout 20° stub teeth for shock loads: a 1.5 : 1 pair.
12 : 28
12T : 28T · profile-shifted
module 2 · 20°
Profile shift at work: a 12-tooth pinion without undercut, the centre distance stretched from 40 to 41.75 mm.
40 : 80
40T : 80T · precision, rack D
module 1 · 20° · ISO 53 rack D
A precision 2 : 1 pair: ISO 53 rack D, tight DIN 3967 backlash, hub pins to a mating part.
20 : 40
20T : 40T · 10 DP, 14½°
10 DP · 14½°
The classic catalogue pair: 10 DP, 14½° pressure angle, keyed inch bores and hubs.
30 : 90
30T : 90T · 24 DP, ¼" bores
24 DP · 20°
A 3 : 1 instrument pair in 24 DP on ¼" shafts, #4-40 set screws.
16 : 32
16T : 32T · Fellows 8/10 stub
8/10 DP Fellows stub
Fellows stub teeth, 8/10 pitch: the short, strong form of machine-tool gearing.
18 in 72
18T in a 72T ring · 4 : 1
module 1 · 20°
An internal (ring) gear and its pinion: compact, both turning the same way.
16 in 64
16T in a 64T helical ring
module 1.5 · 20° · helical 15°
A helical ring gear: the pinion and the ring share one hand.
20 in 80
20T in an 80T herringbone ring
module 2 · 20° · herringbone 25°
A herringbone ring gear and pinion: no axial thrust, 4 : 1.
20 + rack
20T pinion and rack · module 1.5
module 1.5 · 20°
A linear drive: a module 1.5 rack, 94 mm of travel per pinion turn.
18 + rack
18T pinion and helical rack
module 2 · 20° · helical 20°
A helical rack and pinion: smoother and quieter linear motion, the teeth leaning 20°.
24 : 96
24T : 96T · 4 : 1, a 294 mm spoked gear
module 3 · 20°
A big six-spoke module 3 gear: a wide rim, a thinned web and a keyed hub with a set screw.
20 : 60
20T : 60T · module 4 herringbone
module 4 · 20° · herringbone 30°
A heavy herringbone set, 3 : 1, the 285 mm gear spoked.
Designing is free; the STL, STEP, DXF and SVG files download from the app for tokens. Each set was checked in the Gear Designer and opens with no warnings.