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.
Sample · module 2 · 20° · helical 20°
18T pinion and helical rack
A helical rack and pinion: smoother and quieter linear motion, the teeth leaning 20°.
Build it with your AI
Using the CheapCAD Tools connector, design a rack and pinion in Gear Designer: module 2 mm, helical, helix angle 20°, face width 15 mm. Gear 1: 18 teeth, an 8 mm bore. Gear 2: 24 teeth, a rack. Check the design, apply any Auto-fix it suggests, then export both gears as STL and give me the download link.
Paste it into Claude, ChatGPT or any AI app with the CheapCAD Tools connector, and it designs this gear set with you, checks it and hands you the files. How to connect your AI.
What's in this design
Gear 1 · 18 teeth
- 18T gear · tip Ø42.3 mm · bore Ø8 mm
Rack · 24 teeth
- 24-tooth rack
The mesh · module 2 · 20° · helical 20°
- 120.4 mm of rack travel per pinion turn · contact ratio 1.6 + overlap 0.82 · backlash 0.115–0.221 mm
The link opens both parts in the Gear Designer's 3D Mode. Change the teeth, module or pitch, bore, hub or spokes, then download STL, STEP, DXF or SVG.
More samples
Related gear sets
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.