{
 "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": "shaft-spacers",
 "name": "Shaft spacers for Ø3, Ø5 and Ø8 shafts, 1 to 5 mm",
 "kind": "hardware",
 "category": "Stirling engines",
 "group": "Drives & mechanisms",
 "year": null,
 "question": "What thrust spacers set the gaps along a small crankshaft?",
 "tags": [
  "spacer",
  "washer",
  "shaft",
  "thrust",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "shaft spacer 5mm",
  "thrust washer 8mm shaft",
  "crankshaft spacer",
  "3mm shaft spacer"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 12,
 "url": "https://xemstudio.com/objects/shaft-spacers/",
 "sheet_txt": "https://xemstudio.com/objects/shaft-spacers/sheet.txt",
 "sheet": {
  "basis": "Flat rings at the shaft Ø, OD = shaft + 5, in 1, 2, 3 and 5 mm thicknesses",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Flat rings: Ø3 × Ø8, Ø5 × Ø10 and Ø8 × Ø13 (bore × OD), each 1, 2, 3 and 5 thick.",
   "Stacked on the shaft they set the 1 mm gaps between tower, web, rod and flywheel; any gap from 1 to 11 mm is a sum of the four.",
   "The bore is the shaft Ø; the fit is listed under Mating features."
  ],
  "table": {
   "columns": [
    "shaft Ø",
    "OD",
    "thicknesses"
   ],
   "rows": [
    [
     3,
     8,
     "1 / 2 / 3 / 5"
    ],
    [
     5,
     10,
     "1 / 2 / 3 / 5"
    ],
    [
     8,
     13,
     "1 / 2 / 3 / 5"
    ]
   ]
  }
 },
 "sheet_text": "Shaft spacers for Ø3, Ø5 and Ø8 shafts, 1 to 5 mm — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/shaft-spacers/  (CC BY 4.0)\nBasis: Flat rings at the shaft Ø, OD = shaft + 5, in 1, 2, 3 and 5 mm thicknesses\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Flat rings: Ø3 × Ø8, Ø5 × Ø10 and Ø8 × Ø13 (bore × OD), each 1, 2, 3 and 5 thick.\n- Stacked on the shaft they set the 1 mm gaps between tower, web, rod and flywheel; any gap from 1 to 11 mm is a sum of the four.\n- The bore is the shaft Ø; the fit is listed under Mating features.\n\nshaft Ø  OD  thicknesses\n3  8  1 / 2 / 3 / 5\n5  10  1 / 2 / 3 / 5\n8  13  1 / 2 / 3 / 5\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, 12 parts): https://xemstudio.com/files/hardware/shaft-spacers/index.json\nAPI: https://xemstudio.com/api/geometry?object=shaft-spacers\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": [
  "stirling-crankshafts",
  "shaft-collars",
  "flat-washers-metric",
  "crank-stands-625"
 ],
 "fits": [
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "stirling-crankshafts",
     "why": "bore = shaft Ø"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "crank-stands-625",
     "why": "between the 625 and the crank disc"
    }
   ]
  },
  {
   "role": "Alternatives",
   "items": [
    {
     "slug": "flat-washers-metric",
     "why": "ISO 7089 washers"
    }
   ]
  }
 ],
 "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": "shafts, rods, pins",
   "exact": "Ø3 / Ø5 / Ø8",
   "mates": "the bores listed on each mating object",
   "fit": "slide",
   "files": "all"
  },
  {
   "feature": "spacer bore",
   "exact": "Ø3 / Ø5 / Ø8",
   "mates": "shaft",
   "fit": "slide",
   "files": "spacer-"
  }
 ],
 "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 spacer goes on a 5 mm crankshaft?",
   "a": "Ø5 bore × Ø10 OD, 1, 2, 3 or 5 thick."
  },
  {
   "q": "How do I make a 4 mm gap?",
   "a": "Stack the 1 and 3, or two 2s."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "spacer-3mm-t1",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t1.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t1.stl",
   "note": "thrust spacer for a Ø3 shaft, 1 mm: sets the 1 mm gaps between tower, web, rod and flywheel"
  },
  {
   "file": "spacer-3mm-t2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t2.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t2.stl",
   "note": "thrust spacer for a Ø3 shaft, 2 mm: sets the 1 mm gaps between tower, web, rod and flywheel"
  },
  {
   "file": "spacer-3mm-t3",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t3.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t3.stl",
   "note": "thrust spacer for a Ø3 shaft, 3 mm: sets the 1 mm gaps between tower, web, rod and flywheel"
  },
  {
   "file": "spacer-3mm-t5",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t5.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-3mm-t5.stl",
   "note": "thrust spacer for a Ø3 shaft, 5 mm: sets the 1 mm gaps between tower, web, rod and flywheel"
  },
  {
   "file": "spacer-5mm-t1",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t1.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t1.stl",
   "note": "thrust spacer for a Ø5 shaft, 1 mm: sets the 1 mm gaps between tower, web, rod and flywheel"
  },
  {
   "file": "spacer-5mm-t2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t2.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t2.stl",
   "note": "thrust spacer for a Ø5 shaft, 2 mm: sets the 1 mm gaps between tower, web, rod and flywheel"
  },
  {
   "file": "spacer-5mm-t3",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t3.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t3.stl",
   "note": "thrust spacer for a Ø5 shaft, 3 mm: sets the 1 mm gaps between tower, web, rod and flywheel"
  },
  {
   "file": "spacer-5mm-t5",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t5.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-5mm-t5.stl",
   "note": "thrust spacer for a Ø5 shaft, 5 mm: sets the 1 mm gaps between tower, web, rod and flywheel"
  },
  {
   "file": "spacer-8mm-t1",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t1.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t1.stl",
   "note": "thrust spacer for a Ø8 shaft, 1 mm: sets the 1 mm gaps between tower, web, rod and flywheel"
  },
  {
   "file": "spacer-8mm-t2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t2.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t2.stl",
   "note": "thrust spacer for a Ø8 shaft, 2 mm: sets the 1 mm gaps between tower, web, rod and flywheel"
  },
  {
   "file": "spacer-8mm-t3",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t3.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t3.stl",
   "note": "thrust spacer for a Ø8 shaft, 3 mm: sets the 1 mm gaps between tower, web, rod and flywheel"
  },
  {
   "file": "spacer-8mm-t5",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t5.step",
   "stl": "https://xemstudio.com/files/hardware/stirling-shafts-and-rods/spacer-8mm-t5.stl",
   "note": "thrust spacer for a Ø8 shaft, 5 mm: sets the 1 mm gaps between tower, web, rod and flywheel"
  }
 ],
 "markdown": "https://xemstudio.com/objects/shaft-spacers/index.md"
}