# Flanged power cylinder liner Ø16, 20, 25, 30

> What are the dimensions of a flanged power cylinder for a Stirling engine?

- Category: Stirling engines › Drives & mechanisms
- Kind: Hardware
- Basis: Bore 16–30, 3 mm wall, flange Ø(D + 24) × 4 with 4 × M3 clearance (Ø3.4, ISO 273) on Ø(D + 16)
- Page: https://xemstudio.com/objects/power-cylinder-liner/ · JSON: https://xemstudio.com/api/geometry?object=power-cylinder-liner · Plain text: https://xemstudio.com/objects/power-cylinder-liner/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses

**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.

## Notes

- The power cylinder of the gamma engines when not using a syringe: a tube D bore × D + 6 outside, with a 4 thick flange of Ø(D + 24) at its base.
- Four Ø3.4 holes at 45°, 135°, 225° and 315° on a Ø(D + 16) circle take M3 screws to the base or head.
- The power piston of the same bore runs in it (fit: run); its swept volume at 12 mm stroke is in the table.

## Mating features (exact size; open press / slide / run / socket by your process clearance, leave designed and clamp as drawn)

| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| liner bore | Ø16 / Ø20 / Ø25 / Ø30 | piston | run | liner-* |
| liner flange holes | Ø3.4 | M3 screw clearance | designed | liner-* |

## Sizes

| file | bore | outside | length | flange | hole circle | mL per 12 mm stroke |
|---|---|---|---|---|---|---|
| liner-16x40-flanged | 16 | 22 | 40 | 40 | 32 | 2.41 |
| liner-20x45-flanged | 20 | 26 | 45 | 44 | 36 | 3.77 |
| liner-25x50-flanged | 25 | 31 | 50 | 49 | 41 | 5.89 |
| liner-30x55-flanged | 30 | 36 | 55 | 54 | 46 | 8.48 |

## Where the files are

- Wikipedia: [Crosshead](https://en.wikipedia.org/wiki/Crosshead) — web — CC BY-SA 4.0 (text)
- Wikipedia: [Piston](https://en.wikipedia.org/wiki/Piston) — web — CC BY-SA 4.0 (text)
- James R. Senft: [Miniature Stirling engine piston fits (LTD book)](https://www.stirlingengine.com/) — book — reference (verify at link)
- Long Earth Society: [Engine builds](https://longearthsociety.com/engineering/) — web, video — LES site

## Free STEP/STL (4 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/power-cylinder-liner/index.json

- liner-16x40-flanged: [STEP](https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-16x40-flanged.step) · [STL](https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-16x40-flanged.stl) — power cylinder liner Ø16 bore × 40, 3 wall, 4 mm flange Ø40 with 4 × M3 clearance (Ø3.4) on Ø32
- liner-20x45-flanged: [STEP](https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-20x45-flanged.step) · [STL](https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-20x45-flanged.stl) — power cylinder liner Ø20 bore × 45, 3 wall, 4 mm flange Ø44 with 4 × M3 clearance (Ø3.4) on Ø36
- liner-25x50-flanged: [STEP](https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-25x50-flanged.step) · [STL](https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-25x50-flanged.stl) — power cylinder liner Ø25 bore × 50, 3 wall, 4 mm flange Ø49 with 4 × M3 clearance (Ø3.4) on Ø41
- liner-30x55-flanged: [STEP](https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-30x55-flanged.step) · [STL](https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-30x55-flanged.stl) — power cylinder liner Ø30 bore × 55, 3 wall, 4 mm flange Ø54 with 4 × M3 clearance (Ø3.4) on Ø46

## How it fits

### Goes in or on
- [Base plate for 1.5, 2 and 3 in tri-clamp Stirling engines](https://xemstudio.com/objects/tri-clamp-engine-base-plate/): flange on the base plate

### Connects to
- [Power piston Ø16, 20, 25, 30 with Ø3 wrist-pin boss](https://xemstudio.com/objects/power-piston/): piston of the same bore inside (run)

### Alternatives
- [Plastic syringes 1–60 mL as pistons and cylinders](https://xemstudio.com/objects/plastic-syringes/): syringe barrel as the cylinder
- [Borosilicate test tubes, 10×75 to 30×200 mm](https://xemstudio.com/objects/borosilicate-test-tubes/): glass tube as the cylinder
- [Free-piston cylinder liner Ø30 × 120 and Ø40 × 160](https://xemstudio.com/objects/free-piston-cylinder-liner/): Ø30 / Ø40 plain liners

### Also needed
- [Socket head cap screws, M2–M8 (ISO 4762 / DIN 912)](https://xemstudio.com/objects/socket-head-cap-screws-metric/): 4 × M3

## Questions

**What power cylinder for a 2 in tri-clamp gamma?**

Ø20 × 45: at 12 mm stroke it sweeps 3.77 mL, in range for the Ø46 × 90 displacer at 20 mm stroke.

**What is the bolt pattern on the liner flange?**

4 × Ø3.4 on a circle 16 mm larger than the bore (Ø36 for the Ø20 liner).

## Fits with

- [Power piston Ø16, 20, 25, 30 with Ø3 wrist-pin boss](https://xemstudio.com/objects/power-piston/)
- [Crosshead Ø8 × 24 for a Ø3 piston rod](https://xemstudio.com/objects/crosshead-8mm/)
- [Crosshead guide, Ø8 bore × 30](https://xemstudio.com/objects/crosshead-guide-8mm/)
- [Base plate for 1.5, 2 and 3 in tri-clamp Stirling engines](https://xemstudio.com/objects/tri-clamp-engine-base-plate/)
- [Build list: Gamma Stirling, 2 in tri-clamp](https://xemstudio.com/objects/list-gamma-2in-tri-clamp/)