Double-sided gear rack, module 1, 100 mm, pitch lines 12 mm apart — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/double-sided-rack-m1-100-pitch-12/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance
Catalog version: 2026-10-20

Overall (mm): length 100.0, width 14.0, height 8.0
- 100 × 8 bar with full-depth module 1 teeth (ISO 53, 20°) on both edges, tooth centres in line at x = kπ, pitch lines 12 mm apart (roots 9.5 apart); two Ø3.4 holes. Two gears of any equal size, one each side, drive it straight with the same force on both edges.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
module  1
length  100 mm
pitch lines  y = ±6
width  8 mm
holes  2 × Ø3.4 at x = ±40

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Henry T. Brown (1868, public domain): Five Hundred and Seven Mechanical Movements — scan on archive.org — web — Publisher's page; dimensions are facts — https://archive.org/details/fivehundredseven00browiala
- 507movements.com: Brown's movement No. 115: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_115.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/double-rack-two-gears-mechanism/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/double-sided-rack-m1-100-pitch-12/index.json
API: https://xemstudio.com/api/geometry?object=double-sided-rack-m1-100-pitch-12