Strap-brake lever: fulcrum and strap pins Ø4 24 mm apart, handle to 142 mm — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/strap-brake-lever-130-pins24/  (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 153.0, width 12.0, height 5.0
- 5 mm lever pivoted on a Ø4 fulcrum pin that also anchors one end of the strap; the other end is pinned 24 mm along it, so a small turn of the lever pulls that end and closes the strap on the drum with a 142 mm handle's leverage (≈ 6 : 1).
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
pins  2 × Ø4, 24 mm apart
handle  142 mm from the fulcrum
thickness  5 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. 242: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_242.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/crane-strap-brake-mechanism/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/strap-brake-lever-130-pins24/index.json
API: https://xemstudio.com/api/geometry?object=strap-brake-lever-130-pins24