# Linear alternator module spools: 2 in × 42 mm bored Ø48.00 and 2 in × 25.4 mm (fabrication spec)

> What custom tri-clamp spools does the clamp-in linear alternator module need?

- Category: Hardware › Sanitary clamp fittings
- Kind: Hardware
- Basis: Fabrication specs on standard 2 in ferrules (ISO 2852 faces as gen_hardware draws them, BPE tube Ø50.8 × 1.65); lengths set by the module's stroke, the leaves' joints and two high-pressure clamps per spool
- Page: https://xemstudio.com/objects/linear-alternator-module-spools-2in/ · JSON: https://xemstudio.com/api/geometry?object=linear-alternator-module-spools-2in · Plain text: https://xemstudio.com/objects/linear-alternator-module-spools-2in/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

- Two plain custom spools, both full 2 in sanitary fittings with a standard ferrule face at each end. With the catalog's stock 2 in × 3 in spool bored Ø48.00 between them they make the body of my linear alternator module: face A — 42 bored — leaf 1 — 3 in bored — leaf 2 — 25.4 — face B.
- 42 mm spool, bored: the bore opened from Ø47.5 to Ø48.00 end to end and finished as a running bore (wall 1.40). It is the piston's cylinder: the cup's 24 mm land runs in it as a clearance seal. Spec line: '2 in × 42 mm clamp × clamp spool, tube Ø50.8 × 1.65, bore finished Ø48.00 through'.
- 25.4 mm spool: two 0.5 in (12.7 mm) short weld ferrules welded back to back, nothing else: room for leaf 2's hub and collar to travel ±6 mm. Spec line: '2 in × 25.4 mm clamp × clamp spool, two short ferrules'.
- Both are as short as two high-pressure clamps side by side allow: each clamp needs about 10 mm either side of its joint plane. Hoop stress at the 15 bar gauge relief setting: 27.5 MPa in the 1.40 bored wall, 23.0 MPa in the plain tube; the builder checks that against what the spools are made of.

## 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 |
|---|---|---|---|---|
| bore | Ø48.00 × 42 | piston cup land Ø48.00 × 24 (clearance seal) | run | spool-2in-42mm-bored* |
| faces | ISO 2852 2 in, both ends | face A: Type B gasket + clamp to the engine; other face: half gaskets round leaf 1 (closed module) or Type B gasket + clamp to the open frame base | clamp | spool-2in-42mm-bored* |
| faces | ISO 2852 2 in, both ends | joint 2: half gaskets round leaf 2; face B: Type B gasket + clamp to the port cap or the next device | clamp | spool-2in-25.4mm* |
| bore | Ø47.5 (as made) | leaf 2's upper collar and the tube rod's end (no contact) | designed | spool-2in-25.4mm* |

## Sizes

| spool | face_to_face_mm | bore_mm | wall_mm | faces | made from |
|---|---|---|---|---|---|
| spool-2in-42mm-bored-48.00 | 42 | 48.00 (finished) | 1.4 | ISO 2852 2 in, both | two ferrules + tube, bored |
| spool-2in-25.4mm | 25.4 | 47.5 (as made) | 1.65 | ISO 2852 2 in, both | two 12.7 short weld ferrules |

## Where the files are

- ISO (via iTeh sample): [ISO 2852 clamp liners: face profile and flange / groove diameters](https://cdn.standards.iteh.ai/samples/7850/eb49c396488d408c8ced3e2961d76cf3/ISO-2852-1974.pdf) — PDF — standard excerpt; dimensions are facts
- ASME: [BPE Bioprocessing Equipment (tube OD and wall, clamp fittings)](https://www.asme.org/codes-standards/find-codes-standards/bpe-bioprocessing-equipment) — standard — ASME; dimensions are facts (verify at link)
- Xem Studio: [tools/gen_la_module.py: the module's geometry, masses, bounce volume, natural frequencies and every number on these pages](https://xemstudio.com/) — code — CC BY 4.0
- Long Earth Society: [Engine 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/linear-alternator-module-spools-2in/index.json

- spool-2in-42mm-bored-48.00: [STEP](https://xemstudio.com/files/hardware/linear-alternator-module-spools-2in/spool-2in-42mm-bored-48.00.step) · [STL](https://xemstudio.com/files/hardware/linear-alternator-module-spools-2in/spool-2in-42mm-bored-48.00.stl) — 2 in × 42 mm spool, ISO 2852 faces both ends, bore finished Ø48.00 end to end (wall 1.40): the module's piston cylinder, face A to the engine
- spool-2in-25.4mm: [STEP](https://xemstudio.com/files/hardware/linear-alternator-module-spools-2in/spool-2in-25.4mm.step) · [STL](https://xemstudio.com/files/hardware/linear-alternator-module-spools-2in/spool-2in-25.4mm.stl) — 2 in × 25.4 mm spool: two 12.7 mm short weld ferrules back to back, ISO 2852 faces, as-made Ø47.5 bore: the module's face B end

## Questions

**Can I order these?**

Yes: both are standard 2 in ferrules on standard tube; the bored spool then has its bore finished to Ø48.00 end to end, as the other bored spools on this site.

**Which version uses which?**

The 42 mm bored spool is in both versions of the module (closed and open frame); the 25.4 mm spool only in the closed one.

**Why not a stock 3 in spool at each end?**

It would work and add 85 mm of length; on the working side every extra millimetre is dead volume in the engine under test.

## Fits with

- [Linear alternator module mover: Ø48 piston cup, 40-magnet carrier and tube rod, sprung on two leaves](https://xemstudio.com/objects/linear-alternator-module-mover-2in/)
- [Linear alternator module open frame, 2 in: frame base, leaf seats, clamp rings, stator sleeve and top plate](https://xemstudio.com/objects/linear-alternator-module-open-frame-2in/)
- [2 in × 3 in spool with the bore finished Ø48.00 (bored and honed power cylinder)](https://xemstudio.com/objects/tri-clamp-spool-bored-honed/)
- [Tri-clamp spools to a custom length (fabrication spec): 2 in × 340.7 and 310.7 mm, ¾ in × 146.7 and 80.4 mm](https://xemstudio.com/objects/tri-clamp-custom-length-spools/)
- [High-pressure bolted sanitary clamp, 2 in (bought part: ratings, no drawing)](https://xemstudio.com/objects/sanitary-high-pressure-clamp/)
- [Build list: Linear alternator module, 2 in, closed (sealed bounce space, chargeable)](https://xemstudio.com/objects/list-linear-alternator-module-2in-closed/)
- [Build list: Linear alternator module, 2 in, open frame (exposed flexures)](https://xemstudio.com/objects/list-linear-alternator-module-2in-open/)