Ross yoke a = h = 20 for two parallel syringes — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/ross-yoke/  (CC BY 4.0)
Basis: Linkage solved over a full turn (720 steps) in the generator: crank e 6, yoke a = h = 20, rocking link 40 from a pivot at (−40, 20), con-rods 60
Catalog version: 2026-10-20

Sizes: see table below
- The triangular rocker of the Ross yoke alpha. Its half-width equals its height (a = h = 20), which puts the two top corners a quarter-turn apart: piston phase 90.0°, strokes 17.0 and 17.2 mm.
- Bottom vertex: a Ø3 hole (fit: run) that rides on the crank pin. Top corners at ±20: Ø3 holes (fit: press) for the con-rod pins. Between them, the top-middle Ø3 hole (press) for the rocking-link pin.
- Outline 52 × 32 × 6 with 3 mm corner radii.

parameter  value
a (half-width)  20
h (height)  20
outline  52 × 32 × 6
crank-pin hole  Ø3 run
con-rod and rocking pins  3 × Ø3 press
phase  90.0°
strokes  17.0 / 17.2
max con-rod angle  0.91°

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: Ross yoke — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Ross_yoke
- 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/ross-yoke/index.json
API: https://xemstudio.com/api/geometry?object=ross-yoke