{
 "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": "htd-bored-power-spool",
 "name": "Bored 2 in power spool: 2 in × 5 in spool bored to Ø48.00",
 "kind": "hardware",
 "category": "Stirling engines",
 "group": "Tri-clamp engine parts",
 "year": null,
 "question": "How do I make a power cylinder from a 2 inch tri-clamp spool?",
 "tags": [
  "htd",
  "power cylinder",
  "bored spool",
  "tri-clamp"
 ],
 "aliases": [
  "bored tri clamp spool",
  "tri clamp power cylinder",
  "honed sanitary spool piston"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/htd-bored-power-spool/",
 "sheet_txt": "https://xemstudio.com/objects/htd-bored-power-spool/sheet.txt",
 "sheet": {
  "basis": "Fabrication spec: a 2 in spool (tube Ø50.8 × 1.65) 127 face to face, its bore finished to Ø48.00 end to end (a machinist bores and hones it); exact geometry",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "The stock bore is Ø47.5; finished to Ø48.00 it leaves 1.40 of wall. The piston is drawn at Ø48.00 exactly: the running fit is the machinist's (see Mating features).",
   "Both faces stay standard ISO 2852 2 in faces: Type B gaskets and stock 2 in clamps at each end."
  ],
  "table": {
   "columns": [
    "part",
    "length_mm",
    "bore_mm",
    "wall_mm"
   ],
   "rows": [
    [
     "spool-2in-5in-bored-48.00",
     127,
     48,
     1.4
    ]
   ]
  }
 },
 "sheet_text": "Bored 2 in power spool: 2 in × 5 in spool bored to Ø48.00 — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/htd-bored-power-spool/  (CC BY 4.0)\nBasis: Fabrication spec: a 2 in spool (tube Ø50.8 × 1.65) 127 face to face, its bore finished to Ø48.00 end to end (a machinist bores and hones it); exact geometry\nCatalog version: 2026-10-20\n\nSizes: see table below\n- The stock bore is Ø47.5; finished to Ø48.00 it leaves 1.40 of wall. The piston is drawn at Ø48.00 exactly: the running fit is the machinist's (see Mating features).\n- Both faces stay standard ISO 2852 2 in faces: Type B gaskets and stock 2 in clamps at each end.\n\npart  length_mm  bore_mm  wall_mm\nspool-2in-5in-bored-48.00  127.0  48.0  1.4\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\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, 1 parts): https://xemstudio.com/files/hardware/htd-bored-power-spool/index.json\nAPI: https://xemstudio.com/api/geometry?object=htd-bored-power-spool\n",
 "sources": [
  {
   "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": [
  "list-htd-10in",
  "htd-power-pistons"
 ],
 "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 × 127 (finished)",
   "mates": "power piston Ø48.00",
   "fit": "run",
   "files": "all"
  },
  {
   "feature": "faces",
   "exact": "ISO 2852 2 in",
   "mates": "tc-gasket-2in + 2 in clamp",
   "fit": "clamp",
   "files": "all"
  }
 ],
 "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": "Why 48.00?",
   "a": "The smallest round number that cleans up the stock Ø47.5 bore along its whole length, faces included."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "spool-2in-5in-bored-48.00",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/htd-bored-power-spool/spool-2in-5in-bored-48.00.step",
   "stl": "https://xemstudio.com/files/hardware/htd-bored-power-spool/spool-2in-5in-bored-48.00.stl",
   "note": "2 in spool, 127 face to face (5 in), bored through to Ø48.00 over its full length; ISO 2852 faces"
  }
 ],
 "markdown": "https://xemstudio.com/objects/htd-bored-power-spool/index.md"
}