{
 "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": "power-cylinder-liner",
 "name": "Flanged power cylinder liner Ø16, 20, 25, 30",
 "kind": "hardware",
 "category": "Stirling engines",
 "group": "Drives & mechanisms",
 "year": null,
 "question": "What are the dimensions of a flanged power cylinder for a Stirling engine?",
 "tags": [
  "power cylinder",
  "liner",
  "gamma",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "stirling power cylinder",
  "flanged cylinder liner",
  "power piston cylinder 20mm"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 4,
 "url": "https://xemstudio.com/objects/power-cylinder-liner/",
 "sheet_txt": "https://xemstudio.com/objects/power-cylinder-liner/sheet.txt",
 "sheet": {
  "basis": "Bore 16–30, 3 mm wall, flange Ø(D + 24) × 4 with 4 × M3 clearance (Ø3.4, ISO 273) on Ø(D + 16)",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "The power cylinder of the gamma engines when not using a syringe: a tube D bore × D + 6 outside, with a 4 thick flange of Ø(D + 24) at its base.",
   "Four Ø3.4 holes at 45°, 135°, 225° and 315° on a Ø(D + 16) circle take M3 screws to the base or head.",
   "The power piston of the same bore runs in it (fit: run); its swept volume at 12 mm stroke is in the table."
  ],
  "table": {
   "columns": [
    "file",
    "bore",
    "outside",
    "length",
    "flange",
    "hole circle",
    "mL per 12 mm stroke"
   ],
   "rows": [
    [
     "liner-16x40-flanged",
     16,
     22,
     40,
     40,
     32,
     2.41
    ],
    [
     "liner-20x45-flanged",
     20,
     26,
     45,
     44,
     36,
     3.77
    ],
    [
     "liner-25x50-flanged",
     25,
     31,
     50,
     49,
     41,
     5.89
    ],
    [
     "liner-30x55-flanged",
     30,
     36,
     55,
     54,
     46,
     8.48
    ]
   ]
  }
 },
 "sheet_text": "Flanged power cylinder liner Ø16, 20, 25, 30 — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/power-cylinder-liner/  (CC BY 4.0)\nBasis: Bore 16–30, 3 mm wall, flange Ø(D + 24) × 4 with 4 × M3 clearance (Ø3.4, ISO 273) on Ø(D + 16)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- The power cylinder of the gamma engines when not using a syringe: a tube D bore × D + 6 outside, with a 4 thick flange of Ø(D + 24) at its base.\n- Four Ø3.4 holes at 45°, 135°, 225° and 315° on a Ø(D + 16) circle take M3 screws to the base or head.\n- The power piston of the same bore runs in it (fit: run); its swept volume at 12 mm stroke is in the table.\n\nfile  bore  outside  length  flange  hole circle  mL per 12 mm stroke\nliner-16x40-flanged  16  22  40  40  32  2.41\nliner-20x45-flanged  20  26  45  44  36  3.77\nliner-25x50-flanged  25  31  50  49  41  5.89\nliner-30x55-flanged  30  36  55  54  46  8.48\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Wikipedia: Crosshead — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Crosshead\n- Wikipedia: Piston — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Piston\n- James R. Senft: Miniature Stirling engine piston fits (LTD book) — book — reference [verify license at link] — https://www.stirlingengine.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, 4 parts): https://xemstudio.com/files/hardware/power-cylinder-liner/index.json\nAPI: https://xemstudio.com/api/geometry?object=power-cylinder-liner\n",
 "sources": [
  {
   "publisher": "Wikipedia",
   "title": "Crosshead",
   "url": "https://en.wikipedia.org/wiki/Crosshead",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Wikipedia",
   "title": "Piston",
   "url": "https://en.wikipedia.org/wiki/Piston",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "James R. Senft",
   "title": "Miniature Stirling engine piston fits (LTD book)",
   "url": "https://www.stirlingengine.com/",
   "formats": [
    "book"
   ],
   "license": "reference",
   "license_verified": false,
   "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": [
  "power-piston",
  "crosshead-8mm",
  "crosshead-guide-8mm",
  "tri-clamp-engine-base-plate",
  "list-gamma-2in-tri-clamp"
 ],
 "fits": [
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "tri-clamp-engine-base-plate",
     "why": "flange on the base plate"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "power-piston",
     "why": "piston of the same bore inside (run)"
    }
   ]
  },
  {
   "role": "Alternatives",
   "items": [
    {
     "slug": "plastic-syringes",
     "why": "syringe barrel as the cylinder"
    },
    {
     "slug": "borosilicate-test-tubes",
     "why": "glass tube as the cylinder"
    },
    {
     "slug": "free-piston-cylinder-liner",
     "why": "Ø30 / Ø40 plain liners"
    }
   ]
  },
  {
   "role": "Also needed",
   "items": [
    {
     "slug": "socket-head-cap-screws-metric",
     "why": "4 × M3"
    }
   ]
  }
 ],
 "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": "liner bore",
   "exact": "Ø16 / Ø20 / Ø25 / Ø30",
   "mates": "piston",
   "fit": "run",
   "files": "liner-"
  },
  {
   "feature": "liner flange holes",
   "exact": "Ø3.4",
   "mates": "M3 screw clearance",
   "fit": "designed",
   "files": "liner-"
  }
 ],
 "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": "What power cylinder for a 2 in tri-clamp gamma?",
   "a": "Ø20 × 45: at 12 mm stroke it sweeps 3.77 mL, in range for the Ø46 × 90 displacer at 20 mm stroke."
  },
  {
   "q": "What is the bolt pattern on the liner flange?",
   "a": "4 × Ø3.4 on a circle 16 mm larger than the bore (Ø36 for the Ø20 liner)."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "liner-16x40-flanged",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-16x40-flanged.step",
   "stl": "https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-16x40-flanged.stl",
   "note": "power cylinder liner Ø16 bore × 40, 3 wall, 4 mm flange Ø40 with 4 × M3 clearance (Ø3.4) on Ø32"
  },
  {
   "file": "liner-20x45-flanged",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-20x45-flanged.step",
   "stl": "https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-20x45-flanged.stl",
   "note": "power cylinder liner Ø20 bore × 45, 3 wall, 4 mm flange Ø44 with 4 × M3 clearance (Ø3.4) on Ø36"
  },
  {
   "file": "liner-25x50-flanged",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-25x50-flanged.step",
   "stl": "https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-25x50-flanged.stl",
   "note": "power cylinder liner Ø25 bore × 50, 3 wall, 4 mm flange Ø49 with 4 × M3 clearance (Ø3.4) on Ø41"
  },
  {
   "file": "liner-30x55-flanged",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-30x55-flanged.step",
   "stl": "https://xemstudio.com/files/hardware/power-cylinder-piston-crosshead/liner-30x55-flanged.stl",
   "note": "power cylinder liner Ø30 bore × 55, 3 wall, 4 mm flange Ø54 with 4 × M3 clearance (Ø3.4) on Ø46"
  }
 ],
 "markdown": "https://xemstudio.com/objects/power-cylinder-liner/index.md"
}