Rhombic drive crank pin Ø3 × 17 — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/rhombic-crank-pin/  (CC BY 4.0)
Basis: Ø3 pin at the gear's Ø3 crank-pin hole; 0.4 chamfer on one end; length = gear web + 1 mm + two links
Catalog version: 2026-10-20

Sizes: see table below
- The crank pin pressed into each rhombic gear 7 mm off its axis: Ø3 × 17 with a 0.4 mm chamfer on one end.
- It runs from the gear web's back face through the web (6, fit: press), a 1 mm gap and the lower and upper links (5 each, fit: run), ending flush with the upper link.

parameter  value
diameter  3
length  17.0
chamfer  0.4

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: Rhombic drive — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Rhombic_drive
- Wikipedia: Stirling engine — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Stirling_engine
- Philips Research / Meijer: The Philips Stirling engine (rhombic drive papers, 1958–1965) — web — reference [verify license at link] — https://en.wikipedia.org/wiki/Rhombic_drive#History
- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/

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