{
 "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": "can-engine-displacer",
 "name": "Can-engine displacer Ø54 × 25, Ø62 × 30, Ø72 × 35",
 "kind": "standard",
 "category": "Stirling engines",
 "group": "Can & LTD engines",
 "year": null,
 "question": "What size displacer goes in a soda-can Stirling engine?",
 "tags": [
  "displacer",
  "can engine",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "can stirling displacer size",
  "soda can stirling displacer",
  "displacer dimensions 66 mm can",
  "can engine displacer stl"
 ],
 "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/can-engine-displacer/",
 "sheet_txt": "https://xemstudio.com/objects/can-engine-displacer/sheet.txt",
 "sheet": {
  "basis": "Displacer = can bore − 4 (2 mm radial gap, designed; 2.1 mm in the Ø76.2 can); Ø2 hole at the 2 mm rod",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "The displacer that shuttles air between the hot and cold ends of the can. Each is a solid cylinder with a Ø2 hole on its axis for the 2 mm displacer rod.",
   "The 2 mm radial gap to the can wall (2.1 mm in the 76.2 can) is designed: the air flows round the displacer through it."
  ],
  "table": {
   "columns": [
    "file",
    "can",
    "diameter",
    "length",
    "radial gap",
    "rod hole"
   ],
   "rows": [
    [
     "can-displacer-62x30",
     "Ø66 (12 oz)",
     62,
     30,
     2,
     2
    ],
    [
     "can-displacer-54x25",
     "Ø58 (sleek)",
     54,
     25,
     2,
     2
    ],
    [
     "can-displacer-72x35",
     "Ø76.2 (steel 300)",
     72,
     35,
     2.1,
     2
    ]
   ]
  }
 },
 "sheet_text": "Can-engine displacer Ø54 × 25, Ø62 × 30, Ø72 × 35 — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/can-engine-displacer/  (CC BY 4.0)\nBasis: Displacer = can bore − 4 (2 mm radial gap, designed; 2.1 mm in the Ø76.2 can); Ø2 hole at the 2 mm rod\nCatalog version: 2026-10-20\n\nSizes: see table below\n- The displacer that shuttles air between the hot and cold ends of the can. Each is a solid cylinder with a Ø2 hole on its axis for the 2 mm displacer rod.\n- The 2 mm radial gap to the can wall (2.1 mm in the 76.2 can) is designed: the air flows round the displacer through it.\n\nfile  can  diameter  length  radial gap  rod hole\ncan-displacer-62x30  Ø66 (12 oz)  62  30  2.0  2\ncan-displacer-54x25  Ø58 (sleek)  54  25  2.0  2\ncan-displacer-72x35  Ø76.2 (steel 300)  72  35  2.1  2\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Wikipedia: Stirling engine — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Stirling_engine\n- Long Earth Society: Can engine build — video, web — LES site — https://longearthsociety.com/engineering/\n- Long Earth Society: Engine builds (videos and write-ups) — 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/can-engine-displacer/index.json\nAPI: https://xemstudio.com/api/geometry?object=can-engine-displacer\n",
 "sources": [
  {
   "publisher": "Wikipedia",
   "title": "Stirling engine",
   "url": "https://en.wikipedia.org/wiki/Stirling_engine",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Long Earth Society",
   "title": "Can engine build",
   "url": "https://longearthsociety.com/engineering/",
   "formats": [
    "video",
    "web"
   ],
   "license": "LES site",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Long Earth Society",
   "title": "Engine builds (videos and write-ups)",
   "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": [
  "can-engine-cap",
  "beverage-cans",
  "steel-food-cans",
  "craft-sticks",
  "list-can-engine"
 ],
 "fits": [
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "beverage-cans",
     "why": "Ø62 in the Ø66 can, 2 mm radial gap"
    },
    {
     "slug": "steel-food-cans",
     "why": "Ø72 in the Ø76.2 can"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "can-engine-cap",
     "why": "its 2 mm rod runs in the cap's Ø2 bore"
    }
   ]
  },
  {
   "role": "Also needed",
   "items": [
    {
     "slug": "craft-sticks",
     "why": "2 mm wire rod in the Ø2 hole"
    }
   ]
  }
 ],
 "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": "displacer-to-can gap",
   "exact": "2 radial (Ø62 / 54 / 49.3 / 72 in Ø66 / 58 / 53.3 / 76.2)",
   "mates": "can bore",
   "fit": "designed",
   "files": "can-displacer-"
  },
  {
   "feature": "displacer rod bore",
   "exact": "Ø2",
   "mates": "2 mm wire rod",
   "fit": "press",
   "files": "can-displacer-"
  }
 ],
 "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 size displacer for a 12 oz can Stirling engine?",
   "a": "Ø62 × 30 with a Ø2 rod hole: 2 mm radial gap to the Ø66 can."
  },
  {
   "q": "Why is there a gap round the displacer?",
   "a": "The air has to flow past it from the hot end to the cold end; the 2 mm radial gap is that passage, by design."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "can-displacer-62x30",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-62x30.step",
   "stl": "https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-62x30.stl",
   "note": "displacer for a Ø66 can: Ø62 × 30 (2 mm radial gap: designed), Ø2 bore for the 2 mm wire rod"
  },
  {
   "file": "can-displacer-54x25",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-54x25.step",
   "stl": "https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-54x25.stl",
   "note": "displacer for a Ø58 sleek can: Ø54 × 25 (2 mm radial gap: designed), Ø2 rod bore"
  },
  {
   "file": "can-displacer-49x25",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-49x25.step",
   "stl": "https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-49x25.stl",
   "note": "displacer for a Ø53.3 slim can: Ø49.3 × 25 (2 mm radial gap: designed), Ø2 rod bore"
  },
  {
   "file": "can-displacer-72x35",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-72x35.step",
   "stl": "https://xemstudio.com/files/hardware/can-engine-printed-kit/can-displacer-72x35.stl",
   "note": "displacer for a Ø76.2 can: Ø72 × 35 (2.1 mm radial gap: designed), Ø2 rod bore"
  }
 ],
 "markdown": "https://xemstudio.com/objects/can-engine-displacer/index.md"
}