Triangular eccentric: curved (Reuleaux) triangle of width 30, pivoted at a corner — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/triangular-eccentric-reuleaux-w30/  (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 30.0, width 37.0, height 18.0
- Curved triangle of constant width 30 mm (three arcs of radius 30 about the opposite corners), 8 thick, with a Ø14 boss and a Ø6 blind bore at one corner: turned about that corner inside a yoke 30 mm wide, it moves the yoke with dwells at both ends.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
width  30 mm (constant)
pivot  a corner, Ø14 boss, Ø6 blind bore
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. 91: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_091.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/triangular-eccentric-mechanism/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/triangular-eccentric-reuleaux-w30/index.json
API: https://xemstudio.com/api/geometry?object=triangular-eccentric-reuleaux-w30