{
 "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": "printer-calibration-coupons",
 "name": "Printer calibration coupons: hole, pin, nut-trap, T-slot tongue and bearing-pocket gauges",
 "kind": "hardware",
 "category": "Stirling engines",
 "group": "Generators & instruments",
 "year": null,
 "question": "How do I calibrate my 3D printer so holes and shafts fit the files in this library?",
 "tags": [
  "calibration",
  "tolerance",
  "test print",
  "gauge",
  "fit",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "3d printer hole calibration",
  "hole tolerance test print",
  "bearing pocket tolerance",
  "nut trap tolerance",
  "press fit tolerance 3d print",
  "calibration cube alternative",
  "xy compensation test"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 8,
 "url": "https://xemstudio.com/objects/printer-calibration-coupons/",
 "sheet_txt": "https://xemstudio.com/objects/printer-calibration-coupons/sheet.txt",
 "sheet": {
  "basis": "Every file on this site assumes: pivot hole = pin + 0.2, press fit = pin − 0.05, bearing pocket = OD + 0.2 (OD + 0.3 above 20 mm), nut trap = AF + 0.3, T-slot tongue 5.8 in a 6 mm slot. These coupons find your printer's offset so those assumptions hold",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Print the Ø3 hole gauge; push a 3 mm dowel pin through each: the first that slips freely is your 'clearance', the last that needs a tap is your 'press'. If 3.2 slips and 3.0 presses, your printer matches the library and nothing needs changing. If it takes 3.4 to slip, set a horizontal hole compensation of +0.2 mm in the slicer (or scale holes in CAD).",
   "Pin gauge: the 3.0 pin should enter a 623 bearing bore with finger pressure; if only 2.9 does, external features print fat: set XY compensation −0.05. Nut gauge: the M3 nut should push into the 5.8 AF trap and not fall out of 5.6. Tongue gauge against real 2020: 5.8 slides, 6.0 binds. Pocket gauge: a 608 presses into 22.2 with a thumb and holds.",
   "Do this once per printer and filament (PETG shrinks less than PLA, ABS more); write the two numbers (hole offset, XY offset) in your slicer profile. After that every STEP and STL on xemstudio.com fits as drawn, and an AI agent designing around these sheets can use the stated clearances without guessing."
  ],
  "table": {
   "columns": [
    "gauge",
    "what it tests",
    "pass condition"
   ],
   "rows": [
    [
     "hole 2.8–3.6",
     "Ø3 pivots / M3 clearance",
     "3.0 press, 3.2 slip, 3.4 clearance"
    ],
    [
     "hole 4.8–5.6",
     "Ø5 shafts",
     "5.0 press, 5.2 slip"
    ],
    [
     "hole 7.8–8.6",
     "Ø8 shafts",
     "8.0 press, 8.2 slip"
    ],
    [
     "pin 2.8–3.2 / 4.8–5.2",
     "printed pins into bearings",
     "3.0 / 5.0 enters finger-tight"
    ],
    [
     "nut trap M3/M4",
     "captive nuts",
     "5.8 / 7.2 AF snug"
    ],
    [
     "tongue 5.6–6.0",
     "T-slot brackets",
     "5.8 slides in 2020"
    ],
    [
     "pocket 10/16/22",
     "623 / 625 / 608 pockets",
     "+0.2 thumb press"
    ]
   ]
  }
 },
 "sheet_text": "Printer calibration coupons: hole, pin, nut-trap, T-slot tongue and bearing-pocket gauges — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/printer-calibration-coupons/  (CC BY 4.0)\nBasis: Every file on this site assumes: pivot hole = pin + 0.2, press fit = pin − 0.05, bearing pocket = OD + 0.2 (OD + 0.3 above 20 mm), nut trap = AF + 0.3, T-slot tongue 5.8 in a 6 mm slot. These coupons find your printer's offset so those assumptions hold\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Print the Ø3 hole gauge; push a 3 mm dowel pin through each: the first that slips freely is your 'clearance', the last that needs a tap is your 'press'. If 3.2 slips and 3.0 presses, your printer matches the library and nothing needs changing. If it takes 3.4 to slip, set a horizontal hole compensation of +0.2 mm in the slicer (or scale holes in CAD).\n- Pin gauge: the 3.0 pin should enter a 623 bearing bore with finger pressure; if only 2.9 does, external features print fat: set XY compensation −0.05. Nut gauge: the M3 nut should push into the 5.8 AF trap and not fall out of 5.6. Tongue gauge against real 2020: 5.8 slides, 6.0 binds. Pocket gauge: a 608 presses into 22.2 with a thumb and holds.\n- Do this once per printer and filament (PETG shrinks less than PLA, ABS more); write the two numbers (hole offset, XY offset) in your slicer profile. After that every STEP and STL on xemstudio.com fits as drawn, and an AI agent designing around these sheets can use the stated clearances without guessing.\n\ngauge  what it tests  pass condition\nhole 2.8–3.6  Ø3 pivots / M3 clearance  3.0 press, 3.2 slip, 3.4 clearance\nhole 4.8–5.6  Ø5 shafts  5.0 press, 5.2 slip\nhole 7.8–8.6  Ø8 shafts  8.0 press, 8.2 slip\npin 2.8–3.2 / 4.8–5.2  printed pins into bearings  3.0 / 5.0 enters finger-tight\nnut trap M3/M4  captive nuts  5.8 / 7.2 AF snug\ntongue 5.6–6.0  T-slot brackets  5.8 slides in 2020\npocket 10/16/22  623 / 625 / 608 pockets  +0.2 thumb press\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Wikipedia: Engineering tolerance — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Engineering_tolerance\n- Prusa: Knowledge base: XY size compensation — web — Prusa KB [verify license at link] — https://help.prusa3d.com/article/xy-size-compensation_125045\n- Long Earth Society: Engine and rig builds — web, video — LES site — https://longearthsociety.com/engineering/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 8 parts): https://xemstudio.com/files/hardware/printer-calibration-coupons/index.json\nAPI: https://xemstudio.com/api/geometry?object=printer-calibration-coupons\n",
 "sources": [
  {
   "publisher": "Wikipedia",
   "title": "Engineering tolerance",
   "url": "https://en.wikipedia.org/wiki/Engineering_tolerance",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Prusa",
   "title": "Knowledge base: XY size compensation",
   "url": "https://help.prusa3d.com/article/xy-size-compensation_125045",
   "formats": [
    "web"
   ],
   "license": "Prusa KB",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Long Earth Society",
   "title": "Engine and rig 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": [
  "ball-bearings-metric",
  "dowel-pins-metric",
  "hex-nuts-metric",
  "t-slot-brackets-and-nuts",
  "heat-set-inserts",
  "can-engine-printed-kit"
 ],
 "faq": [
  {
   "q": "What tolerance do the files on this site assume?",
   "a": "Pivot holes pin + 0.2 mm, press fits pin − 0.05, bearing pockets OD + 0.2 (0.3 above 20 mm), nut traps AF + 0.3, T-slot tongues 5.8 mm. Print the gauges once to confirm your printer lands there."
  },
  {
   "q": "My holes print too small; what do I change?",
   "a": "Measure which gauge hole slips over a 3 mm pin; the difference from 3.2 is your offset. Set it as hole/horizontal compensation in the slicer (+0.1 to +0.3 is typical for PLA on a 0.4 nozzle)."
  },
  {
   "q": "Why do printed holes come out undersize?",
   "a": "Extrusion width rounding on curves, plastic shrink and the slicer's arc approximation all push material inward; outside features come out fat by a similar amount. A one-time XY compensation fixes both."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "hole-gauge-m3-2-8-to-3-6",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/printer-calibration-coupons/hole-gauge-m3-2-8-to-3-6.step",
   "stl": "https://xemstudio.com/files/hardware/printer-calibration-coupons/hole-gauge-m3-2-8-to-3-6.stl",
   "note": "hole gauge for Ø3 pins/screws: 2.8–3.6 in 0.1 steps (find press, slip and clearance)"
  },
  {
   "file": "hole-gauge-m5-4-8-to-5-6",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/printer-calibration-coupons/hole-gauge-m5-4-8-to-5-6.step",
   "stl": "https://xemstudio.com/files/hardware/printer-calibration-coupons/hole-gauge-m5-4-8-to-5-6.stl",
   "note": "hole gauge for Ø5 shafts: 4.8–5.6"
  },
  {
   "file": "hole-gauge-m8-7-8-to-8-6",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/printer-calibration-coupons/hole-gauge-m8-7-8-to-8-6.step",
   "stl": "https://xemstudio.com/files/hardware/printer-calibration-coupons/hole-gauge-m8-7-8-to-8-6.stl",
   "note": "hole gauge for Ø8 shafts: 7.8–8.6"
  },
  {
   "file": "pin-gauge-2-8-to-3-2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/printer-calibration-coupons/pin-gauge-2-8-to-3-2.step",
   "stl": "https://xemstudio.com/files/hardware/printer-calibration-coupons/pin-gauge-2-8-to-3-2.stl",
   "note": "printed pin gauge 2.8–3.2: which prints to a true Ø3 hole in a bearing?"
  },
  {
   "file": "pin-gauge-4-8-to-5-2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/printer-calibration-coupons/pin-gauge-4-8-to-5-2.step",
   "stl": "https://xemstudio.com/files/hardware/printer-calibration-coupons/pin-gauge-4-8-to-5-2.stl",
   "note": "printed pin gauge 4.8–5.2 (625 bearing bore test)"
  },
  {
   "file": "nut-trap-gauge-m3-m4",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/printer-calibration-coupons/nut-trap-gauge-m3-m4.step",
   "stl": "https://xemstudio.com/files/hardware/printer-calibration-coupons/nut-trap-gauge-m3-m4.stl",
   "note": "nut-trap gauge: M3 at 5.5/5.7/5.9 AF, M4 at 7.0/7.2/7.4"
  },
  {
   "file": "extrusion-tongue-gauge-6mm",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/printer-calibration-coupons/extrusion-tongue-gauge-6mm.step",
   "stl": "https://xemstudio.com/files/hardware/printer-calibration-coupons/extrusion-tongue-gauge-6mm.stl",
   "note": "T-slot tongue gauge: 5.6 / 5.8 / 6.0 mm tongues for a 6 mm slot"
  },
  {
   "file": "bearing-pocket-gauge-623-625-608",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/printer-calibration-coupons/bearing-pocket-gauge-623-625-608.step",
   "stl": "https://xemstudio.com/files/hardware/printer-calibration-coupons/bearing-pocket-gauge-623-625-608.stl",
   "note": "bearing pocket gauge: Ø10.0/10.2/10.4 (623), Ø16.0/16.2/16.4 (625), Ø22.0/22.2/22.4 (608), 6 deep"
  }
 ],
 "markdown": "https://xemstudio.com/objects/printer-calibration-coupons/index.md"
}