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Two-pin crank disc, pins 90° apart, 6 / 8 / 10 mm throw
What crank disc gives 90° phase for an alpha Stirling with parallel cylinders? · Hardware · basis: Alpha phase 90°: two pins a quarter-turn apart for parallel or in-line cylinders
Long Earth Society build part. Alpha demonstrator and the twin-crank for the two-spool alpha. The engines
Exact dimensions. Every file is drawn at true size with no printing tolerance. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your printer's or process's clearance before making the part. Mating features
- sizes
- 3 in table
Notes
- 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).
Sizes
| 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° |
Mating features
Drawn at the exact size. Open press, slide, run and socket features by your process's clearance; leave designed gaps and clamp fits as drawn.
| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| disc bore | Ø5 | Ø5 shaft (M3 grub) | slide | crank-disc-* |
| disc pin holes | Ø3 | Ø3 crank pins | press | crank-disc-* |
| disc grub hole | Ø2.5 | M3 tap drill | designed | crank-disc-* |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| Wikipedia | Stirling engine | web | CC BY-SA 4.0 (text) |
| Long Earth Society | Engine builds | web, video | LES site |
Free files
★ Free files 3 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| crank-disc-2pin-90deg-e6 | crank disc with two Ø3 pin holes 90° apart at 6 mm (stroke 12): for PARALLEL alpha cylinders (not a 90° V, which uses one pin) | STEP · STL |
| crank-disc-2pin-90deg-e8 | crank disc with two Ø3 pin holes 90° apart at 8 mm (stroke 16): for PARALLEL alpha cylinders (not a 90° V, which uses one pin) | STEP · STL |
| crank-disc-2pin-90deg-e10 | crank disc with two Ø3 pin holes 90° apart at 10 mm (stroke 20): for PARALLEL alpha cylinders (not a 90° V, which uses one pin) | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=two-pin-crank-disc-90
How it fits
Connects to
Crankshafts Ø3, Ø5 and Ø8 with full-length D-flatØ5 shaft in the bore
Con-rods with Ø3 pin ends, 45 and 60 mm, 8 × 5one con-rod per pinAlternatives
Alpha V-twin crank disc Ø26, one pin, 16 mm strokeone-pin disc for a 90° V
Ross yoke a = h = 20 for two parallel syringesparallel cylinders on a Ross yokeAlso needed
Dowel pins, 2–6 mmØ3 crank pinsYou might also need
Questions
What phase angle does an alpha Stirling use?
90°: with parallel cylinders put the two pins a quarter-turn apart, as on this disc.
Can I use the two-pin disc on a V-twin?
Not on a 90° V: it would give 0° or 180°. A 90° V uses one pin for both rods.