{
 "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": "hall-sensor-mount",
 "name": "Hall sensor mount for TO-92S (A3144 / SS49E)",
 "kind": "hardware",
 "category": "Stirling engines",
 "group": "Generators & instruments",
 "year": null,
 "question": "How do I mount a hall sensor to measure RPM?",
 "tags": [
  "hall sensor",
  "rpm",
  "a3144",
  "ss49e",
  "sensor mount",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "hall sensor mount 3d print",
  "a3144 mount",
  "ss49e holder",
  "hall sensor rpm mount",
  "to92 sensor holder"
 ],
 "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/hall-sensor-mount/",
 "sheet_txt": "https://xemstudio.com/objects/hall-sensor-mount/sheet.txt",
 "sheet": {
  "basis": "Block sized to the A3144 UA / SS49E TO-92S body (4.09 × 1.52 mm), M3 foot hole at ISO 273 clearance (Ø3.4)",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "The mount is a 14 × 10 × 20 mm block with a 4.09 × 1.52 × 10 mm deep slot in the top face for a TO-92S (UA) hall sensor body, exact.",
   "The slot sits 1.24 mm behind one 14 mm face, so the sensor's face is that close to the passing magnet side.",
   "A Ø3.4 hole (M3 clearance) runs through the 10 mm thickness, 5 mm above the base, for the screw that holds it.",
   "One magnet passing gives one pulse: rpm = pulses per second × 60 / magnets per revolution; on the 12-pole axial-flux rotor that is pulses × 60 / 12."
  ],
  "table": {
   "columns": [
    "feature",
    "size_mm"
   ],
   "rows": [
    [
     "block",
     "14 × 10 × 20"
    ],
    [
     "sensor slot",
     "4.09 × 1.52 × 10 deep"
    ],
    [
     "slot to face",
     "1.24"
    ],
    [
     "foot hole",
     "Ø3.4 (M3)"
    ]
   ]
  }
 },
 "sheet_text": "Hall sensor mount for TO-92S (A3144 / SS49E) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/hall-sensor-mount/  (CC BY 4.0)\nBasis: Block sized to the A3144 UA / SS49E TO-92S body (4.09 × 1.52 mm), M3 foot hole at ISO 273 clearance (Ø3.4)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- The mount is a 14 × 10 × 20 mm block with a 4.09 × 1.52 × 10 mm deep slot in the top face for a TO-92S (UA) hall sensor body, exact.\n- The slot sits 1.24 mm behind one 14 mm face, so the sensor's face is that close to the passing magnet side.\n- A Ø3.4 hole (M3 clearance) runs through the 10 mm thickness, 5 mm above the base, for the screw that holds it.\n- One magnet passing gives one pulse: rpm = pulses per second × 60 / magnets per revolution; on the 12-pole axial-flux rotor that is pulses × 60 / 12.\n\nfeature  size_mm\nblock  14 × 10 × 20\nsensor slot  4.09 × 1.52 × 10 deep\nslot to face  1.24\nfoot hole  Ø3.4 (M3)\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Wikipedia: Thermocouple — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Thermocouple\n- Wikipedia: Hall effect sensor — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Hall_effect_sensor\n- Wikipedia: Dial indicator — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Dial_indicator\n- Analog Devices: DS18B20 datasheet — PDF — Manufacturer datasheet — https://www.analog.com/en/products/ds18b20.html\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, 1 parts): https://xemstudio.com/files/hardware/hall-sensor-mount/index.json\nAPI: https://xemstudio.com/api/geometry?object=hall-sensor-mount\n",
 "sources": [
  {
   "publisher": "Wikipedia",
   "title": "Thermocouple",
   "url": "https://en.wikipedia.org/wiki/Thermocouple",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Wikipedia",
   "title": "Hall effect sensor",
   "url": "https://en.wikipedia.org/wiki/Hall_effect_sensor",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Wikipedia",
   "title": "Dial indicator",
   "url": "https://en.wikipedia.org/wiki/Dial_indicator",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Analog Devices",
   "title": "DS18B20 datasheet",
   "url": "https://www.analog.com/en/products/ds18b20.html",
   "formats": [
    "PDF"
   ],
   "license": "Manufacturer datasheet",
   "license_verified": true,
   "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": [
  "axial-flux-rotor",
  "encoder-disc",
  "neodymium-disc-magnets",
  "probe-clamps",
  "crank-discs-5mm-bore"
 ],
 "fits": [
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "axial-flux-rotor",
     "why": "faces a rotor magnet: 12 pulses per revolution"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "neodymium-disc-magnets",
     "why": "sensor face 1–2 mm from a passing magnet"
    }
   ]
  },
  {
   "role": "Alternatives",
   "items": [
    {
     "slug": "encoder-disc",
     "why": "optical pickup through an IR slot sensor"
    }
   ]
  }
 ],
 "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": "sensor slot",
   "exact": "4.09 × 1.52",
   "mates": "A3144 UA / SS49E TO-92S body",
   "fit": "press",
   "files": "hall-sensor-mount-"
  },
  {
   "feature": "foot hole",
   "exact": "Ø3.4",
   "mates": "M3 screw clearance",
   "fit": "designed",
   "files": "hall-sensor-mount-"
  }
 ],
 "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 is a TO-92S hall sensor body?",
   "a": "4.09 × 1.52 mm (A3144 UA package, SS49E); the slot is drawn at exactly that."
  },
  {
   "q": "How do I measure Stirling engine RPM with a hall sensor?",
   "a": "Put the sensor 1–2 mm from a magnet on the flywheel or rotor; rpm = pulses per second × 60 / magnets per revolution."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "hall-sensor-mount-to92",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/instrument-mounts/hall-sensor-mount-to92.step",
   "stl": "https://xemstudio.com/files/hardware/instrument-mounts/hall-sensor-mount-to92.stl",
   "note": "hall sensor mount (A3144 UA / SS49E TO-92S): 4.09 × 1.52 body slot, Ø3.4 (M3 clearance) foot hole"
  }
 ],
 "markdown": "https://xemstudio.com/objects/hall-sensor-mount/index.md"
}