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Free-piston cylinder liner Ø30 × 120 and Ø40 × 160
What size cylinder does a free-piston Stirling core use? · Hardware · basis: Bore 30 / 40, length 4 × bore, 3 mm wall
Long Earth Society build part. The LES free-piston test bed: Ø40 core on flexures in a 2 in tri-clamp vessel. 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
- 2 in table
Notes
- The bore that the displacer and power piston share in the beta free-piston core: Ø30 × 120 (Ø36 outside) or Ø40 × 160 (Ø46 outside), 3 mm wall.
- The displacer runs in it with a 0.5 mm radial gap, the power piston with 0.05 mm, and the stop bumpers fit its bore (fit: press).
Sizes
| file | bore | outside | length | wall |
|---|---|---|---|---|
| cylinder-liner-30x120 | 30 | 36 | 120 | 3 |
| cylinder-liner-40x160 | 40 | 46 | 160 | 3 |
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 |
|---|---|---|---|---|
| rod bores | Ø5 | Ø5 rod | slide | all |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| NASA (NTRS, public domain) | Free-piston Stirling engine design and analysis (RE-1000 test results) (1984) | US Government work, public domain | |
| NASA (NTRS, public domain) | Dynamics of free-piston Stirling engines (1987) | US Government work, public domain | |
| Wikipedia | Free-piston engine | web | CC BY-SA 4.0 (text) |
| Wikipedia | Beale number | web | CC BY-SA 4.0 (text) |
| Ohio University | Stirling cycle machine analysis (Urieli), free online | web | Author's site |
| Long Earth Society | Engine builds | web, video | LES site |
Free files
★ Free files 2 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| cylinder-liner-30x120 | cylinder liner Ø30 bore × 120, 3 wall | STEP · STL |
| cylinder-liner-40x160 | cylinder liner Ø40 bore × 160, 3 wall | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=free-piston-cylinder-liner
How it fits
Connects to
Free-piston Stirling displacer Ø29 × 75 and Ø39 ×…displacer inside
Free-piston Stirling power piston Ø29.9 × 30 and…piston inside
Piston stop bumper Ø30 and Ø40 × 6bumpers in the boreAlternatives
Borosilicate test tubes, 10×75 to 30×200 mmglass tube bores
Flanged power cylinder liner Ø16, 20, 25, 30flanged liners Ø16–30You might also need
Questions
How long is the free-piston cylinder?
Four bores: 120 mm for Ø30, 160 mm for Ø40, room for displacer, piston and stops in one bore.
What runs in the liner?
The displacer (0.5 mm radial gap) and the power piston (0.05 mm), one behind the other.