# Shaft spacers for Ø3, Ø5 and Ø8 shafts, 1 to 5 mm

> What thrust spacers set the gaps along a small crankshaft?

- Category: Stirling engines › Drives & mechanisms
- Kind: Hardware
- Basis: Flat rings at the shaft Ø, OD = shaft + 5, in 1, 2, 3 and 5 mm thicknesses
- Page: https://xemstudio.com/objects/shaft-spacers/ · JSON: https://xemstudio.com/api/geometry?object=shaft-spacers · Plain text: https://xemstudio.com/objects/shaft-spacers/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

- Flat rings: Ø3 × Ø8, Ø5 × Ø10 and Ø8 × Ø13 (bore × OD), each 1, 2, 3 and 5 thick.
- Stacked on the shaft they set the 1 mm gaps between tower, web, rod and flywheel; any gap from 1 to 11 mm is a sum of the four.
- The bore is the shaft Ø; the fit is 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 |
|---|---|---|---|---|
| shafts, rods, pins | Ø3 / Ø5 / Ø8 | the bores listed on each mating object | slide | all |
| spacer bore | Ø3 / Ø5 / Ø8 | shaft | slide | spacer-* |

## Sizes

| shaft Ø | OD | thicknesses |
|---|---|---|
| 3 | 8 | 1 / 2 / 3 / 5 |
| 5 | 10 | 1 / 2 / 3 / 5 |
| 8 | 13 | 1 / 2 / 3 / 5 |

## Where the files are

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

## Free STEP/STL (12 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/shaft-spacers/index.json

- spacer-3mm-t1: [STEP](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t1.step) · [STL](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t1.stl) — thrust spacer for a Ø3 shaft, 1 mm: sets the 1 mm gaps between tower, web, rod and flywheel
- spacer-3mm-t2: [STEP](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t2.step) · [STL](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t2.stl) — thrust spacer for a Ø3 shaft, 2 mm: sets the 1 mm gaps between tower, web, rod and flywheel
- spacer-3mm-t3: [STEP](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t3.step) · [STL](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t3.stl) — thrust spacer for a Ø3 shaft, 3 mm: sets the 1 mm gaps between tower, web, rod and flywheel
- spacer-3mm-t5: [STEP](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t5.step) · [STL](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t5.stl) — thrust spacer for a Ø3 shaft, 5 mm: sets the 1 mm gaps between tower, web, rod and flywheel
- spacer-5mm-t1: [STEP](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t1.step) · [STL](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t1.stl) — thrust spacer for a Ø5 shaft, 1 mm: sets the 1 mm gaps between tower, web, rod and flywheel
- spacer-5mm-t2: [STEP](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t2.step) · [STL](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t2.stl) — thrust spacer for a Ø5 shaft, 2 mm: sets the 1 mm gaps between tower, web, rod and flywheel
- spacer-5mm-t3: [STEP](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t3.step) · [STL](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t3.stl) — thrust spacer for a Ø5 shaft, 3 mm: sets the 1 mm gaps between tower, web, rod and flywheel
- spacer-5mm-t5: [STEP](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t5.step) · [STL](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t5.stl) — thrust spacer for a Ø5 shaft, 5 mm: sets the 1 mm gaps between tower, web, rod and flywheel
- spacer-8mm-t1: [STEP](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t1.step) · [STL](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t1.stl) — thrust spacer for a Ø8 shaft, 1 mm: sets the 1 mm gaps between tower, web, rod and flywheel
- spacer-8mm-t2: [STEP](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t2.step) · [STL](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t2.stl) — thrust spacer for a Ø8 shaft, 2 mm: sets the 1 mm gaps between tower, web, rod and flywheel
- spacer-8mm-t3: [STEP](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t3.step) · [STL](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t3.stl) — thrust spacer for a Ø8 shaft, 3 mm: sets the 1 mm gaps between tower, web, rod and flywheel
- spacer-8mm-t5: [STEP](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t5.step) · [STL](https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t5.stl) — thrust spacer for a Ø8 shaft, 5 mm: sets the 1 mm gaps between tower, web, rod and flywheel

## How it fits

### Goes in or on
- [Crankshafts Ø3, Ø5 and Ø8 with full-length D-flat](https://xemstudio.com/objects/stirling-crankshafts/): bore = shaft Ø

### Connects to
- [Crank stands with a 625 pocket, 40 and 60 mm axis height](https://xemstudio.com/objects/crank-stands-625/): between the 625 and the crank disc

### Alternatives
- [Flat washers, M2–M8 (ISO 7089)](https://xemstudio.com/objects/flat-washers-metric/): ISO 7089 washers

## Questions

**What spacer goes on a 5 mm crankshaft?**

Ø5 bore × Ø10 OD, 1, 2, 3 or 5 thick.

**How do I make a 4 mm gap?**

Stack the 1 and 3, or two 2s.

## Fits with

- [Crankshafts Ø3, Ø5 and Ø8 with full-length D-flat](https://xemstudio.com/objects/stirling-crankshafts/)
- [Set-screw shaft collars Ø3 to Ø12](https://xemstudio.com/objects/shaft-collars/)
- [Flat washers, M2–M8 (ISO 7089)](https://xemstudio.com/objects/flat-washers-metric/)
- [Crank stands with a 625 pocket, 40 and 60 mm axis height](https://xemstudio.com/objects/crank-stands-625/)