# Regenerator cage for 2 in and 1.5 in tri-clamp spools (Ø47.5 and Ø34.8)

> How do I hold regenerator mesh inside a tri-clamp spool?

- Category: Stirling engines › Heat & regenerator
- Kind: Hardware
- Basis: Split tube drawn at the tri-clamp spool bore (2 in Ø47.5, 1.5 in Ø34.8), 2 mm split so it closes for insertion
- Page: https://xemstudio.com/objects/regenerator-cage/ · JSON: https://xemstudio.com/api/geometry?object=regenerator-cage · Plain text: https://xemstudio.com/objects/regenerator-cage/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 2 in cage is Ø47.5 OD (= the 2 in spool bore) × 40 long, Ø44 ID, 1.75 mm wall.
- The 1.5 in cage is Ø34.8 OD (= the 1.5 in spool bore) × 30 long, Ø32 ID, 1.4 mm wall.
- Each has a 2 mm split through one wall (designed), so it closes slightly to slide into the bore and springs out against it.
- The regenerator matrix fills the cage bore: Ø44 × 40 on the 2 in size, Ø32 × 30 on the 1.5 in.

## 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 |
|---|---|---|---|---|
| cage OD | Ø47.5 / Ø34.8 | tri-clamp-spool bore 47.5 / 34.8 | socket | regenerator-cage-* |
| cage split | 2 | closes for insertion | designed | regenerator-cage-* |

## Sizes

| cage | od_mm | id_mm | length_mm | split_mm | spool |
|---|---|---|---|---|---|
| regenerator-cage-47-5x40 | 47.5 | 44 | 40 | 2 | 2 in |
| regenerator-cage-34-8x30 | 34.8 | 32 | 30 | 2 | 1.5 in |

## 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-cage/index.json

- regenerator-cage-47-5x40: [STEP](https://xemstudio.com/files/hardware/regenerator-and-heat-materials/regenerator-cage-47-5x40.step) · [STL](https://xemstudio.com/files/hardware/regenerator-and-heat-materials/regenerator-cage-47-5x40.stl) — regenerator cage for a 2 in spool bore: Ø47.5 OD (= bore) × 40, Ø44 ID, 1.75 wall, 2 mm split; pack with mesh or scrubber
- regenerator-cage-34-8x30: [STEP](https://xemstudio.com/files/hardware/regenerator-and-heat-materials/regenerator-cage-34-8x30.step) · [STL](https://xemstudio.com/files/hardware/regenerator-and-heat-materials/regenerator-cage-34-8x30.stl) — regenerator cage for a 1.5 in spool bore: Ø34.8 OD (= bore) × 30, Ø32 ID, 2 mm split

## How it fits

### Goes in or on
- [Tri-clamp spool (two ferrules on a tube), 1.5 and 2 inch](https://xemstudio.com/objects/tri-clamp-spool/): cage OD = spool bore Ø47.5 / Ø34.8 (socket)

### Also needed
- [Regenerator matrix disc Ø44 / Ø32 × 0.5 mm (mesh counts #40–#200)](https://xemstudio.com/objects/regenerator-mesh-disc/): matrix discs stacked in the cage bore
- [Tri-clamp clamp, two-bolt: every flange size ½ to 4 in](https://xemstudio.com/objects/tri-clamp-clamps/): clamps the spool between hot and cold ends

## Questions

**What size regenerator cage for a 2 in tri-clamp spool?**

Ø47.5 OD × 40 mm, Ø44 ID, drawn at the spool bore with a 2 mm split.

**Why is the cage split?**

The 2 mm split lets it close for insertion into the Ø47.5 or Ø34.8 bore; it is a designed gap.

## Fits with

- [Regenerator matrix disc Ø44 / Ø32 × 0.5 mm (mesh counts #40–#200)](https://xemstudio.com/objects/regenerator-mesh-disc/)
- [Tri-clamp spool (two ferrules on a tube), 1.5 and 2 inch](https://xemstudio.com/objects/tri-clamp-spool/)
- [Tri-clamp (Tri-Clover) sanitary ferrule, 1/2 to 4 inch](https://xemstudio.com/objects/tri-clamp-ferrule/)
- [Tri-clamp clamp, two-bolt: every flange size ½ to 4 in](https://xemstudio.com/objects/tri-clamp-clamps/)
- [Thermoacoustic heat exchangers, hot and cold, parallel plate, for 1.5, 2 and 3 in tri-clamp spools](https://xemstudio.com/objects/thermoacoustic-heat-exchanger/)