Watt linkage coupler, 30 mm, centre tracer hole — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/watt-linkage-coupler-30/  (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 40.0, width 10.0, height 5.0
- 10 × 5 mm link with Ø3 holes at −15, 0 and +15 mm: its ends pin to the two radius arms and its middle hole is the point that moves on a near-straight line.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
end centres  30 mm
holes  3 × Ø3

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. 337: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_337.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/watts-linkage-mechanism/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/watt-linkage-coupler-30/index.json
API: https://xemstudio.com/api/geometry?object=watt-linkage-coupler-30