{
 "version": "2026-10-20",
 "license": "Dimension sheets are written by Xem Studio from the cited sources and are free to use (CC BY 4.0, attribute 'Xem Studio'). Linked files belong to their publishers under the license shown; Xem Studio does not host them. 'license_verified: false' means the license shown is from memory or the publisher's page as last read and should be confirmed at the link before commercial use.",
 "slug": "linear-alternator-module-spools-2in",
 "name": "Linear alternator module spools: 2 in × 42 mm bored Ø48.00 and 2 in × 25.4 mm (fabrication spec)",
 "kind": "hardware",
 "category": "Hardware",
 "group": "Sanitary clamp fittings",
 "year": null,
 "question": "What custom tri-clamp spools does the clamp-in linear alternator module need?",
 "tags": [
  "spool",
  "custom length",
  "bored",
  "honed",
  "fabrication",
  "sanitary",
  "linear alternator",
  "tri-clamp",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "short tri clamp spool",
  "custom length sanitary spool",
  "tri clamp spool bored 48",
  "2 inch spool 25.4 mm",
  "linear alternator module spool"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 2,
 "url": "https://xemstudio.com/objects/linear-alternator-module-spools-2in/",
 "sheet_txt": "https://xemstudio.com/objects/linear-alternator-module-spools-2in/sheet.txt",
 "sheet": {
  "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",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "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."
  ],
  "table": {
   "columns": [
    "spool",
    "face_to_face_mm",
    "bore_mm",
    "wall_mm",
    "faces",
    "made from"
   ],
   "rows": [
    [
     "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"
    ]
   ]
  }
 },
 "sheet_text": "Linear alternator module spools: 2 in × 42 mm bored Ø48.00 and 2 in × 25.4 mm (fabrication spec) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/linear-alternator-module-spools-2in/  (CC BY 4.0)\nBasis: 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\nCatalog version: 2026-10-20\n\nSizes: see table below\n- 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.\n- 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'.\n- 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'.\n- 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.\n\nspool  face_to_face_mm  bore_mm  wall_mm  faces  made from\nspool-2in-42mm-bored-48.00  42  48.00 (finished)  1.4  ISO 2852 2 in, both  two ferrules + tube, bored\nspool-2in-25.4mm  25.4  47.5 (as made)  1.65  ISO 2852 2 in, both  two 12.7 short weld ferrules\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- ISO (via iTeh sample): ISO 2852 clamp liners: face profile and flange / groove diameters — PDF — standard excerpt; dimensions are facts — https://cdn.standards.iteh.ai/samples/7850/eb49c396488d408c8ced3e2961d76cf3/ISO-2852-1974.pdf\n- ASME: BPE Bioprocessing Equipment (tube OD and wall, clamp fittings) — standard — ASME; dimensions are facts [verify license at link] — https://www.asme.org/codes-standards/find-codes-standards/bpe-bioprocessing-equipment\n- Xem Studio: tools/gen_la_module.py: the module's geometry, masses, bounce volume, natural frequencies and every number on these pages — code — CC BY 4.0 — https://xemstudio.com/\n- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 2 parts): https://xemstudio.com/files/hardware/linear-alternator-module-spools-2in/index.json\nAPI: https://xemstudio.com/api/geometry?object=linear-alternator-module-spools-2in\n",
 "sources": [
  {
   "publisher": "ISO (via iTeh sample)",
   "title": "ISO 2852 clamp liners: face profile and flange / groove diameters",
   "url": "https://cdn.standards.iteh.ai/samples/7850/eb49c396488d408c8ced3e2961d76cf3/ISO-2852-1974.pdf",
   "formats": [
    "PDF"
   ],
   "license": "standard excerpt; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "ASME",
   "title": "BPE Bioprocessing Equipment (tube OD and wall, clamp fittings)",
   "url": "https://www.asme.org/codes-standards/find-codes-standards/bpe-bioprocessing-equipment",
   "formats": [
    "standard"
   ],
   "license": "ASME; dimensions are facts",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Xem Studio",
   "title": "tools/gen_la_module.py: the module's geometry, masses, bounce volume, natural frequencies and every number on these pages",
   "url": "https://xemstudio.com/",
   "formats": [
    "code"
   ],
   "license": "CC BY 4.0",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Long Earth Society",
   "title": "Engine builds",
   "url": "https://longearthsociety.com/engineering/",
   "formats": [
    "web",
    "video"
   ],
   "license": "LES site",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "linear-alternator-module-mover-2in",
  "linear-alternator-module-open-frame-2in",
  "tri-clamp-spool-bored-honed",
  "tri-clamp-custom-length-spools",
  "sanitary-high-pressure-clamp",
  "list-linear-alternator-module-2in-closed",
  "list-linear-alternator-module-2in-open"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn.",
 "mating": [
  {
   "feature": "bore",
   "exact": "Ø48.00 × 42",
   "mates": "piston cup land Ø48.00 × 24 (clearance seal)",
   "fit": "run",
   "files": "spool-2in-42mm-bored"
  },
  {
   "feature": "faces",
   "exact": "ISO 2852 2 in, both ends",
   "mates": "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",
   "fit": "clamp",
   "files": "spool-2in-42mm-bored"
  },
  {
   "feature": "faces",
   "exact": "ISO 2852 2 in, both ends",
   "mates": "joint 2: half gaskets round leaf 2; face B: Type B gasket + clamp to the port cap or the next device",
   "fit": "clamp",
   "files": "spool-2in-25.4mm"
  },
  {
   "feature": "bore",
   "exact": "Ø47.5 (as made)",
   "mates": "leaf 2's upper collar and the tube rod's end (no contact)",
   "fit": "designed",
   "files": "spool-2in-25.4mm"
  }
 ],
 "fit_classes": {
  "press": "stays put: pin, tube, bearing or magnet held by interference. Typical FDM: hole +0.0 to +0.1 mm on diameter.",
  "slide": "assembles by hand and is held by a grub, pinch or clamp: shaft in a hub, rod in a socket, spigot in a bore. Typical FDM: +0.2 mm.",
  "run": "turns or slides in use: pin in a link, rod through a guide. Typical FDM: +0.3 mm.",
  "socket": "large sliding fit: syringe barrel, sleeve, bobbin in a bore. Typical FDM: +0.3 mm.",
  "clamp": "split part that closes on the mating part with screws: make it at size.",
  "designed": "a gap that is part of the design (piston fit option, displacer gap, air gap): do not change."
 },
 "faq": [
  {
   "q": "Can I order these?",
   "a": "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."
  },
  {
   "q": "Which version uses which?",
   "a": "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."
  },
  {
   "q": "Why not a stock 3 in spool at each end?",
   "a": "It would work and add 85 mm of length; on the working side every extra millimetre is dead volume in the engine under test."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "spool-2in-42mm-bored-48.00",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "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",
   "note": "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"
  },
  {
   "file": "spool-2in-25.4mm",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "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",
   "note": "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"
  }
 ],
 "markdown": "https://xemstudio.com/objects/linear-alternator-module-spools-2in/index.md"
}