# Regenerator matrix disc Ø44 / Ø32 × 0.5 mm (mesh counts #40–#200)

> What mesh size is used for a Stirling engine regenerator?

- Category: Stirling engines › Heat & regenerator
- Kind: Hardware
- Basis: ASTM E11 wire-mesh geometry (mesh count, wire diameter, opening); discs drawn at the regenerator cage bores, Ø44 and Ø32 × 0.5, Ø3 centre hole
- Page: https://xemstudio.com/objects/regenerator-mesh-disc/ · JSON: https://xemstudio.com/api/geometry?object=regenerator-mesh-disc · Plain text: https://xemstudio.com/objects/regenerator-mesh-disc/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 file is one regenerator matrix disc at its exact size: the bore of its cage (Ø44 or Ø32) × 0.5 mm, with a Ø3 centre hole the displacer rod passes through, drawn as a solid disc (the mesh weave is not modelled).
- Mesh count → wire Ø / opening (ASTM E11): #40 0.25 / 0.42 mm, #60 0.19 / 0.25, #80 0.14 / 0.18, #100 0.10 / 0.15, #150 0.066 / 0.104, #200 0.053 / 0.074.
- Regenerators use #100–#200 discs stacked loosely to 60–70 % porosity; #40–#60 suits low-temperature demonstrators where flow loss matters more than heat capacity.
- On my engines the regenerator is a split cage filled with a stack of #100 matrix discs.

## 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 |
|---|---|---|---|---|
| mesh disc OD | Ø44 / Ø32 | regenerator cage bore Ø44 / Ø32 | socket | mesh-disc-* |
| mesh disc centre hole | Ø3 | Ø3 displacer rod (passes through) | run | mesh-disc-* |

## Sizes

| mesh | wire_mm | opening_mm | use |
|---|---|---|---|
| #40 | 0.25 | 0.42 | low-temperature demonstrator |
| #60 | 0.19 | 0.25 | low-temperature demonstrator |
| #80 | 0.14 | 0.18 | regenerator |
| #100 | 0.1 | 0.15 | regenerator |
| #150 | 0.066 | 0.104 | regenerator |
| #200 | 0.053 | 0.074 | high-temperature regenerator |

## Where the files are

- Wikipedia: [Mesh (scale)](https://en.wikipedia.org/wiki/Mesh_(scale)) — web — CC BY-SA 4.0 (text)
- Wikipedia: [Regenerative heat exchanger](https://en.wikipedia.org/wiki/Regenerative_heat_exchanger) — web — CC BY-SA 4.0 (text)
- Wikipedia: [Steel wool](https://en.wikipedia.org/wiki/Steel_wool) — web — CC BY-SA 4.0 (text)
- McMaster-Carr: [Wire cloth (free STEP per part, for your own design use; no redistribution)](https://www.mcmaster.com/products/wire-cloth/) — STEP, PDF — McMaster-Carr site terms (verify at link)
- Long Earth Society: [Engine and rig builds](https://longearthsociety.com/engineering/) — web, video — LES site

## Free STEP/STL (2 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/regenerator-mesh-disc/index.json

- mesh-disc-44mm: [STEP](https://xemstudio.com/files/hardware/regenerator-and-heat-materials/mesh-disc-44mm.step) · [STL](https://xemstudio.com/files/hardware/regenerator-and-heat-materials/mesh-disc-44mm.stl) — regenerator mesh disc Ø44 × 0.5 with a Ø3 centre hole for the displacer rod: the bore of regenerator-cage-47-5x40 (Ø44), one disc of the stack that fills it
- mesh-disc-32mm: [STEP](https://xemstudio.com/files/hardware/regenerator-and-heat-materials/mesh-disc-32mm.step) · [STL](https://xemstudio.com/files/hardware/regenerator-and-heat-materials/mesh-disc-32mm.stl) — regenerator mesh disc Ø32 × 0.5 with a Ø3 centre hole for the displacer rod: the bore of regenerator-cage-34-8x30 (Ø32), one disc of the stack that fills it

## How it fits

### Goes in or on
- [Regenerator cage for 2 in and 1.5 in tri-clamp spools (Ø47.5 and Ø34.8)](https://xemstudio.com/objects/regenerator-cage/): discs stacked inside the cage bore
- [Tri-clamp displacer: Ø33.6, Ø46 and Ø70.9 for 1.5, 2 and 3 in spools](https://xemstudio.com/objects/tri-clamp-displacer/): matrix in the regenerative displacer's slots

### Also needed
- [Tri-clamp spool (two ferrules on a tube), 1.5 and 2 inch](https://xemstudio.com/objects/tri-clamp-spool/): the spool that holds the regenerator

## Questions

**What mesh size for a Stirling regenerator?**

#100 to #200 (0.10–0.053 mm wire) stacked loosely to 60–70 % porosity; #40–#60 for low-temperature demonstrators.

**What is the wire diameter of #100 mesh?**

0.10 mm with a 0.15 mm opening (ASTM E11); #200 is 0.053 mm wire, 0.074 opening.

**What diameter is the regenerator disc?**

Ø44 × 0.5 mm for the 2 in regenerator cage (its Ø44 bore) and Ø32 × 0.5 for the 1.5 in cage, each with a Ø3 centre hole for the displacer rod.

## Fits with

- [Regenerator cage for 2 in and 1.5 in tri-clamp spools (Ø47.5 and Ø34.8)](https://xemstudio.com/objects/regenerator-cage/)
- [Tri-clamp spool (two ferrules on a tube), 1.5 and 2 inch](https://xemstudio.com/objects/tri-clamp-spool/)
- [Tri-clamp displacer: Ø33.6, Ø46 and Ø70.9 for 1.5, 2 and 3 in spools](https://xemstudio.com/objects/tri-clamp-displacer/)
- [Insulating firebrick 230 × 114 × 64 mm (9 × 4.5 × 2.5 in)](https://xemstudio.com/objects/insulating-firebrick/)
- [Ceramic standoff Ø10 × 20 mm, Ø4.3 hole (M4)](https://xemstudio.com/objects/ceramic-standoff/)