Mutilated pinion, module 1, 20 T with 10 teeth kept (half) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/mutilated-pinion-m1-20t-half/  (CC BY 4.0)
Basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance
Catalog version: 2026-10-20

Overall (mm): length 21.99, width 19.74, height 8.0
- A module 1, 20-tooth spur gear (catalog gear, Ø6 bore, 8 face) with the teeth of one half cut away to the root circle (Ø17.5): it drives for half a turn and is idle for the other half.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
module  1
teeth  10 of 20 (180°)
root Ø (cut half)  17.5 mm
bore  Ø6

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. 114: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_114.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/mutilated-gear-double-rack-mechanism/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/mutilated-pinion-m1-20t-half/index.json
API: https://xemstudio.com/api/geometry?object=mutilated-pinion-m1-20t-half