# Crosshead yokes with a Ø5 stub wrist pin: Ø6, Ø8 and hollow Ø10 rods

> How do I join a con-rod to a piston rod outside the cylinder?

- Category: Hardware › Stirling & thermoacoustic
- Kind: Hardware
- Basis: Design values; Ø5 dowel (ISO 8734) stub pin with a 625 in the con-rod's small end
- Page: https://xemstudio.com/objects/stirling-crosshead-yokes/ · JSON: https://xemstudio.com/api/geometry?object=stirling-crosshead-yokes · Plain text: https://xemstudio.com/objects/stirling-crosshead-yokes/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**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

- A block on the rod's end with a Ø5 dowel pressed 6 mm into its side: the con-rod's 625 runs on the pin beside the block and a Ø5 shaft collar holds it. The rod's axis stays clear, so in the beta the displacer rod passes straight up through the hollow rod's yoke (and its 6 × 10 × 10 bushing guides it there).

## 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 |
|---|---|---|---|---|
| rod sockets | M6 (Ø5.0 × 12) / M8 (Ø6.8 × 12) / M10 × 1 (Ø9.0 × 16) | rod ends | designed | all |
| stub-pin hole | Ø5 × 6 | Ø5 dowel wrist pin | press | all |
| bushing seat | Ø10 × 10 at the top | 6 × 10 × 10 sleeve bushing (guides the displacer rod) | press | yoke-tube10* |

## Sizes

| part | socket | pin height | block |
|---|---|---|---|
| yoke-rod6-m6 | M6 × 12 | 15 | 14 × 14 × 24 |
| yoke-rod8-m8 | M8 × 12 | 16 | 14 × 14 × 26 |
| yoke-tube10-m10x1 | M10 × 1 × 16 | 22 | 14 × 24 × 30 |

## Where the files are

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

## Free STEP/STL (3 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/stirling-crosshead-yokes/index.json

- yoke-rod6-m6: [STEP](https://xemstudio.com/files/hardware/stirling-crosshead-yokes/yoke-rod6-m6.step) · [STL](https://xemstudio.com/files/hardware/stirling-crosshead-yokes/yoke-rod6-m6.stl) — crosshead yoke 14 × 14 × 24 for the rod6 rod: tapped socket from the bottom, Ø5 stub-pin hole 6 deep in the −Y face at 15
- yoke-rod8-m8: [STEP](https://xemstudio.com/files/hardware/stirling-crosshead-yokes/yoke-rod8-m8.step) · [STL](https://xemstudio.com/files/hardware/stirling-crosshead-yokes/yoke-rod8-m8.stl) — crosshead yoke 14 × 14 × 26 for the rod8 rod: tapped socket from the bottom, Ø5 stub-pin hole 6 deep in the −Y face at 16
- yoke-tube10-m10x1: [STEP](https://xemstudio.com/files/hardware/stirling-crosshead-yokes/yoke-tube10-m10x1.step) · [STL](https://xemstudio.com/files/hardware/stirling-crosshead-yokes/yoke-tube10-m10x1.stl) — crosshead yoke 14 × 14 × 30 for the tube10 rod: tapped socket from the bottom, Ø5 stub-pin hole 6 deep in the −Y face at 22, Ø7 passage and Ø10 × 10 bushing seat at the top

## Questions

**Why not a clevis?**

A clevis pin crosses the rod's axis; the beta's coaxial rods need the axis clear.

## Fits with

- [Con-rods and links with a 626 big end and a 625 small end: 55 to 488 mm](https://xemstudio.com/objects/stirling-conrods-626-625/)
- [Ground rods, hollow piston rod and crank shafts for the performance engines (Ø6, Ø8, Ø10 / 7)](https://xemstudio.com/objects/stirling-precision-rods/)
- [Build list: Tri-clamp horizontal gamma generator, 2 in, chargeable](https://xemstudio.com/objects/list-tri-clamp-horizontal-gamma/)
- [Build list: Tri-clamp charged beta, 2 in](https://xemstudio.com/objects/list-tri-clamp-charged-beta/)