Slider-crank mechanism (crank and connecting rod) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/slider-crank-mechanism/  (CC BY 4.0)
Basis: Xem Studio drawing; classic mechanism (Brown No. 92)
Catalog version: 2026-10-20

Sizes: see table below
- A crank of radius r drives a connecting rod of length L whose other end slides on a line through the crank centre. Stroke = 2r (40 mm here).
- Slider position x = r·cosθ + √(L² − r²·sin²θ); the rod ratio L/r (4 here) sets how far the motion departs from simple harmonic.
- It is the piston-engine and pump layout; running backwards (slider drives) it needs a flywheel to pass the dead centres.
- Parts (each has its own page): crank-discs-5mm-bore, connecting-rods-623, crosshead-8mm, crosshead-guide-8mm, pins-3mm. Brown's movement No. 92 shows it (1868).

parameter  value
crank radius r  20 mm
rod length L  80 mm
stroke  40 mm
pins  Ø3
shaft  Ø5

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

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