Eccentric bush Ø16 × 12 with Ø6 bore offset 2.5 mm and a 50 mm lever — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/eccentric-bush-16-bore6-e2-5-lever/  (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 58.0, width 16.0, height 12.0
- Ø16 × 12 bush whose Ø6 bore is 2.5 mm off centre, with a 10 × 4 lever: turning it half a turn in its housing moves the axle 5 mm, more than the 2.25 mm tooth depth of module 1 gears, so the pinion swings fully in or out of mesh.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
bush  Ø16 × 12
bore  Ø6, 2.5 mm off centre
lever  50 × 10 × 4

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. 56: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_056.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/eccentric-back-gear-mechanism/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/eccentric-bush-16-bore6-e2-5-lever/index.json
API: https://xemstudio.com/api/geometry?object=eccentric-bush-16-bore6-e2-5-lever