# Can-engine frame: base, can stand, crank bearings and syringe pad in one part

> What holds a soda-can Stirling engine together: can over the tea light, crank above, syringe beside it?

- Category: Stirling engines › Stirling & thermoacoustic
- Kind: Hardware
- Basis: Placed from the assembled can engine on this site (tools/asm_can-engine.py): 12 oz can cut to 110, tea light 38 × 16 with its cup top 17.5 below the can rim, 623 bearings, syringe-cradle-10ml, 10 mL barrel 111 below the crank axis
- Page: https://xemstudio.com/objects/can-engine-frame/ · JSON: https://xemstudio.com/api/geometry?object=can-engine-frame · Plain text: https://xemstudio.com/objects/can-engine-frame/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses

## Overall (mm)

| length | width | height |
|---|---|---|
| 115.0 | 91.0 | 324.5 |

**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

- One part: a 115 × 91 × 5 base; on it a Ø76 / Ø58 ring the can's standing rim sits on, 38.5 above the table (the tea light stands on the base inside the ring; three 22 × 20 air windows); a 6 mm back board at y 40–46 up to z 270; two posts rising from it to two bearing arms 8 thick along the shaft, each with a Ø10 pocket through it for a 623 on the crank axis at z 312.5; a pad whose face sits 11.95 from the syringe axis, where syringe-cradle-10ml bolts on with 4 × M3 × 16 into tapped holes.
- The cranks are overhung, one at each end of the Ø3 shaft, so no shaft crosses a con-rod: the power con-rod at x −49.8 over the syringe, the displacer con-rod at x 0 over the cap's rod guide; the bearing arms and the Ø100 flywheel sit between the two crank discs.
- The syringe stands tip-down; its Luer tip is joined to the cap's transfer barb by three 20 mm lengths of 4 × 6 tube and two transfer elbows (up from the barb, across, up into the tip).
- The pockets and tapped holes are listed under Mating features.

## 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 |
|---|---|---|---|---|
| can ring seat | Ø76 / Ø58 ring top at z 38.5 | 12 oz can's standing rim (rests on it) | designed | can-engine-frame-* |
| bearing pockets | Ø10 | 623 bearing | press | can-engine-frame-* |
| cradle pad holes | Ø2.5 × 12 | M3 tap drill | designed | can-engine-frame-* |

## Sizes

| feature | position_mm | mates with |
|---|---|---|
| can ring top | 38.5 | 12 oz can standing rim |
| crank axis | z 312.5, y 0 | two 623 bearings (Ø10 pockets) |
| bearing arms (x) | −40.3..−32.3 / −18.5..−10.5 | flywheel between them |
| cradle pad face | y 11.95 | syringe-cradle-10ml base (4 × M3 × 16) |
| syringe axis | x −49.8, y 0 | 10 mL barrel, tip down |

## Where the files are

- Long Earth Society: [Can engine build](https://longearthsociety.com/engineering/) — web, video — LES site

## Free STEP/STL (1 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/can-engine-frame/index.json

- can-engine-frame-12oz: [STEP](https://xemstudio.com/files/hardware/can-engine-frame/can-engine-frame-12oz.step) · [STL](https://xemstudio.com/files/hardware/can-engine-frame/can-engine-frame-12oz.stl) — frame for the 12 oz can engine: 115 × 91 × 5 base, Ø76 / Ø58 can ring (can rim at z 38.5, three air windows), back board, two bearing arms with Ø10 pockets for 623s on the crank axis (z 312.5), syringe-cradle pad (4 × M3 tapped, face 11.95 from the barrel axis)

## Questions

**How high should the can sit over the tea light?**

The frame's ring puts the can's rim 38.5 above the table: a 16 mm tea light on the base leaves 17.5 mm from the cup top to the can.

**Why are the cranks at the ends of the shaft on the can engine?**

A shaft running through a con-rod's plane is swept by the con-rod at top dead centre. With a crank disc at each end and the con-rods outboard, the shaft never meets a con-rod; the bearings and the flywheel sit between the discs.

## Fits with

- [Build list: Soda-can gamma](https://xemstudio.com/objects/list-can-engine/)
- [Aluminium beverage cans: 12 oz standard, 16 oz, 330/500 mL, sleek, slim, mini](https://xemstudio.com/objects/beverage-cans/)
- [Can-engine cap for 53.3, 58, 66 and 76.2 mm cans](https://xemstudio.com/objects/can-engine-cap/)
- [Tea lights, maxi tea lights and votives (heat sources)](https://xemstudio.com/objects/tea-light-candles/)
- [Plastic syringes 1–60 mL as pistons and cylinders](https://xemstudio.com/objects/plastic-syringes/)
- [Socket head cap screws, M2–M8 (ISO 4762 / DIN 912)](https://xemstudio.com/objects/socket-head-cap-screws-metric/)
- [Transfer elbow for 4 × 6 mm tube: a 90° turn in a syringe engine's transfer line](https://xemstudio.com/objects/transfer-elbow-4mm/)