Two-pin crank disc, pins 90° apart, 6 / 8 / 10 mm throw — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/two-pin-crank-disc-90/  (CC BY 4.0)
Basis: Alpha phase 90°: two pins a quarter-turn apart for parallel or in-line cylinders
Catalog version: 2026-10-20

Sizes: see table below
- Ø30 × 6 disc with a Ø5 bore (fit: slide), a Ø2.5 radial hole (M3 tap size) for a grub screw, and two Ø3 pin holes (fit: press) 90° apart at the same throw.
- Throws 6, 8 and 10 mm give strokes of 12, 16 and 20 mm; on a 10 mL syringe (Ø14.5) that is 1.65 mL per 10 mm of stroke.
- For parallel or in-line cylinders only. Cylinders in a 90° V share one pin instead (alpha V-twin crank disc).

file  throw  stroke  disc  bore  pins
crank-disc-2pin-90deg-e6  6  12  Ø30 × 6  5  2 × Ø3 at 90°
crank-disc-2pin-90deg-e8  8  16  Ø30 × 6  5  2 × Ø3 at 90°
crank-disc-2pin-90deg-e10  10  20  Ø30 × 6  5  2 × Ø3 at 90°

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: Stirling engine — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Stirling_engine
- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 3 parts): https://xemstudio.com/files/hardware/two-pin-crank-disc-90/index.json
API: https://xemstudio.com/api/geometry?object=two-pin-crank-disc-90