Lazy tongs (three-cell scissor linkage) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/lazy-tongs-mechanism/  (CC BY 4.0)
Basis: Xem Studio design following Brown No. 144 (1868)
Catalog version: 2026-10-20

Sizes: see table below
- Crossed bars pinned at their middles and ends: closing the handles a little extends the far end a lot. With n cells the end moves n times as far as the first cell's joint (3 here), and every joint stays on the centre line.
- Each bar is the 80 mm centre-hole link; length along the axis = 2·n·40·cos α (207.8 mm at α = 30° here).
- Brown's No. 144 (lazy tongs); the scissor lift and the extending mirror arm are the same linkage.
- Parts (each has its own page): centre-hole-link-80, dowel-pins-metric.
- Brown's movement No. 144 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

parameter  value
cells  3
bars  6 × 80 mm centre-hole links
angle drawn  30° to the axis
reach at 30°  207.8 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. 144: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_144.html

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