# Can-engine displacer Ø54 × 25, Ø62 × 30, Ø72 × 35

> What size displacer goes in a soda-can Stirling engine?

- Category: Stirling engines › Can & LTD engines
- Kind: Standard part
- Basis: Displacer = can bore − 4 (2 mm radial gap, designed; 2.1 mm in the Ø76.2 can); Ø2 hole at the 2 mm rod
- Page: https://xemstudio.com/objects/can-engine-displacer/ · JSON: https://xemstudio.com/api/geometry?object=can-engine-displacer · Plain text: https://xemstudio.com/objects/can-engine-displacer/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 displacer that shuttles air between the hot and cold ends of the can. Each is a solid cylinder with a Ø2 hole on its axis for the 2 mm displacer rod.
- The 2 mm radial gap to the can wall (2.1 mm in the 76.2 can) is designed: the air flows round the displacer through it.

## 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 |
|---|---|---|---|---|
| displacer-to-can gap | 2 radial (Ø62 / 54 / 49.3 / 72 in Ø66 / 58 / 53.3 / 76.2) | can bore | designed | can-displacer-* |
| displacer rod bore | Ø2 | 2 mm wire rod | press | can-displacer-* |

## Sizes

| file | can | diameter | length | radial gap | rod hole |
|---|---|---|---|---|---|
| can-displacer-62x30 | Ø66 (12 oz) | 62 | 30 | 2.0 | 2 |
| can-displacer-54x25 | Ø58 (sleek) | 54 | 25 | 2.0 | 2 |
| can-displacer-72x35 | Ø76.2 (steel 300) | 72 | 35 | 2.1 | 2 |

## Where the files are

- Wikipedia: [Stirling engine](https://en.wikipedia.org/wiki/Stirling_engine) — web — CC BY-SA 4.0 (text)
- Long Earth Society: [Can engine build](https://longearthsociety.com/engineering/) — video, web — LES site
- Long Earth Society: [Engine builds (videos and write-ups)](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/can-engine-displacer/index.json

- can-displacer-62x30: [STEP](https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-62x30.step) · [STL](https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-62x30.stl) — displacer for a Ø66 can: Ø62 × 30 (2 mm radial gap: designed), Ø2 bore for the 2 mm wire rod
- can-displacer-54x25: [STEP](https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-54x25.step) · [STL](https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-54x25.stl) — displacer for a Ø58 sleek can: Ø54 × 25 (2 mm radial gap: designed), Ø2 rod bore
- can-displacer-49x25: [STEP](https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-49x25.step) · [STL](https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-49x25.stl) — displacer for a Ø53.3 slim can: Ø49.3 × 25 (2 mm radial gap: designed), Ø2 rod bore
- can-displacer-72x35: [STEP](https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-72x35.step) · [STL](https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-72x35.stl) — displacer for a Ø76.2 can: Ø72 × 35 (2.1 mm radial gap: designed), Ø2 rod bore

## How it fits

### Goes in or on
- [Aluminium beverage cans: 12 oz standard, 16 oz, 330/500 mL, sleek, slim, mini](https://xemstudio.com/objects/beverage-cans/): Ø62 in the Ø66 can, 2 mm radial gap
- [Steel food cans: soup, vegetable, tuna, #2, #2½, #10, coffee](https://xemstudio.com/objects/steel-food-cans/): Ø72 in the Ø76.2 can

### Connects to
- [Can-engine cap for 53.3, 58, 66 and 76.2 mm cans](https://xemstudio.com/objects/can-engine-cap/): its 2 mm rod runs in the cap's Ø2 bore

### Also needed
- [Craft sticks 114 × 10 × 2 mm and jumbo 150 × 18 × 2 mm](https://xemstudio.com/objects/craft-sticks/): 2 mm wire rod in the Ø2 hole

## Questions

**What size displacer for a 12 oz can Stirling engine?**

Ø62 × 30 with a Ø2 rod hole: 2 mm radial gap to the Ø66 can.

**Why is there a gap round the displacer?**

The air has to flow past it from the hot end to the cold end; the 2 mm radial gap is that passage, by design.

## Fits with

- [Can-engine cap for 53.3, 58, 66 and 76.2 mm cans](https://xemstudio.com/objects/can-engine-cap/)
- [Aluminium beverage cans: 12 oz standard, 16 oz, 330/500 mL, sleek, slim, mini](https://xemstudio.com/objects/beverage-cans/)
- [Steel food cans: soup, vegetable, tuna, #2, #2½, #10, coffee](https://xemstudio.com/objects/steel-food-cans/)
- [Craft sticks 114 × 10 × 2 mm and jumbo 150 × 18 × 2 mm](https://xemstudio.com/objects/craft-sticks/)
- [Build list: Soda-can gamma](https://xemstudio.com/objects/list-can-engine/)