Mangle-wheel pinion, 9 teeth, for Ø4 pins on R40 (cut for both sides of the pin row) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/mangle-pinion-9t-for-pins-r40/  (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 28.18, width 28.53, height 8.0
- 8 mm pinion, pitch radius 12 mm (9 teeth to the wheel's 30 pin positions), Ø6 bore. Its tooth spaces are the envelope of the Ø4 pins as it rolls both outside the pin circle (centres 52 mm apart) and inside it (28 mm), so it clears the pins in either mesh.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
teeth  9
pitch radius  12 mm
tip Ø  28.6 mm
bore  Ø6
thickness  8 mm

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. 36: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_036.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/mangle-wheel-and-pinion-mechanism/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/mangle-pinion-9t-for-pins-r40/index.json
API: https://xemstudio.com/api/geometry?object=mangle-pinion-9t-for-pins-r40