Gear racks: module 1 (100 mm) and module 2 (150 mm) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/gear-racks/  (CC BY 4.0)
Basis: Involute rack, 20° pressure angle, module 1 and 2, matching the spur gears here
Catalog version: 2026-10-20

Sizes: see table below
- Straight toothed bars that mesh with the module 1 and module 2 spur gears to turn rotation into straight-line travel.
- One turn of a z-tooth pinion moves the rack π × module × z: 62.8 mm for a 20-tooth module 1 gear.
- Module 1: 100 mm long, 8 × 8, three Ø3.4 mounting holes. Module 2: 150 mm long, 12 high × 10 wide.

module  length  section  travel per turn, 20 T pinion
1  100 mm  8 × 8  62.8 mm
2  150 mm  12 × 10  125.7 mm

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: Rack and pinion — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Rack_and_pinion
- Long Earth Society: Engine and rig builds on extrusion frames — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 2 parts): https://xemstudio.com/files/hardware/gear-racks/index.json
API: https://xemstudio.com/api/geometry?object=gear-racks