{
 "version": "2026-10-20",
 "license": "Dimension sheets: CC BY 4.0. Standard and published-size files: CC BY 4.0. Xem Studio's own designs (files_license = Xem Studio Design License): free to use and sell things from, not to redistribute as files — https://xemstudio.com/license/. Other publishers' files: their own license, linked beside them.",
 "slug": "pulley-gear-unit-40-m1-25-16t-bore8",
 "name": "Pulley and gear unit: Ø40 × 16 flat pulley with a module 1.25, 16-tooth gear, Ø8 bore",
 "kind": "modern",
 "category": "Hardware",
 "group": "Mechanism parts",
 "year": null,
 "question": "What is a pulley-and-gear unit?",
 "tags": [
  "mechanism part",
  "507 mechanical movements"
 ],
 "aliases": [
  "pulley gear",
  "gear pulley",
  "polea con engranaje",
  "Riemenscheibe mit Zahnrad"
 ],
 "overall_mm": {
  "length": 40,
  "width": 40,
  "height": 24
 },
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 "xem_status": "free-files",
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 "url": "https://xemstudio.com/objects/pulley-gear-unit-40-m1-25-16t-bore8/",
 "sheet_txt": "https://xemstudio.com/objects/pulley-gear-unit-40-m1-25-16t-bore8/sheet.txt",
 "sheet": {
  "basis": "Xem Studio design following Brown's figure (1868); true size, no printing allowance",
  "overall_mm": {
   "length": 40,
   "width": 40,
   "height": 24
  },
  "notes": [
   "A Ø40 × 16 flat-belt pulley and a module 1.25, 16-tooth spur gear (pitch Ø20, 8 mm face) made in one piece, running loose on a Ø8 shaft: whichever unit the belt is on drives the gear cluster beside it, so shifting the belt changes speed.",
   "Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features)."
  ],
  "table": {
   "columns": [
    "dimension",
    "value"
   ],
   "rows": [
    [
     "pulley",
     "Ø40 × 16"
    ],
    [
     "gear",
     "module 1.25, 16 T, pitch Ø20, 8 face"
    ],
    [
     "bore",
     "Ø8 (runs loose)"
    ]
   ]
  }
 },
 "sheet_text": "Pulley and gear unit: Ø40 × 16 flat pulley with a module 1.25, 16-tooth gear, Ø8 bore — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/pulley-gear-unit-40-m1-25-16t-bore8/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)\nBasis: Xem Studio design following Brown's figure (1868); true size, no printing allowance\nCatalog version: 2026-10-20\n\nOverall (mm): length 40.0, width 40.0, height 24.0\n- A Ø40 × 16 flat-belt pulley and a module 1.25, 16-tooth spur gear (pitch Ø20, 8 mm face) made in one piece, running loose on a Ø8 shaft: whichever unit the belt is on drives the gear cluster beside it, so shifting the belt changes speed.\n- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).\n\ndimension  value\npulley  Ø40 × 16\ngear  module 1.25, 16 T, pitch Ø20, 8 face\nbore  Ø8 (runs loose)\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Henry T. Brown (1868, public domain): Five Hundred and Seven Mechanical Movements — scan on archive.org — web — Publisher's page; dimensions are facts — https://archive.org/details/fivehundredseven00browiala\n- 507movements.com: Brown's movement No. 59: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_059.html\n- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/belt-shifted-gears-three-speed-mechanism/\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/pulley-gear-unit-40-m1-25-16t-bore8/index.json\nAPI: https://xemstudio.com/api/geometry?object=pulley-gear-unit-40-m1-25-16t-bore8\n",
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   "title": "Five Hundred and Seven Mechanical Movements — scan on archive.org",
   "url": "https://archive.org/details/fivehundredseven00browiala",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "507movements.com",
   "title": "Brown's movement No. 59: figure, his text and an animation",
   "url": "https://507movements.com/mm_059.html",
   "formats": [
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   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
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   "title": "drawing",
   "url": "https://xemstudio.com/objects/belt-shifted-gears-three-speed-mechanism/",
   "formats": [
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   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
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 "related": [
  "belt-shifted-gears-three-speed-mechanism"
 ],
 "fits": [],
 "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": [],
 "faq": [
  {
   "q": "What is a pulley-and-gear unit?",
   "a": "A Ø40 × 16 flat-belt pulley and a module 1.25, 16-tooth spur gear (pitch Ø20, 8 mm face) made in one piece, running loose on a Ø8 shaft: whichever unit the belt is on drives the gear cluster beside it, so shifting the belt changes speed."
  }
 ],
 "files_license": {
  "name": "Xem Studio Design License",
  "holder": "Xem Studio",
  "url": "https://xemstudio.com/license/",
  "note": "Xem Studio's own design: free to use, print, modify and sell things made from it; not to be republished or redistributed as files."
 },
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   "license": "Xem Studio Design License",
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   "stl": "https://xemstudio.com/files/hardware/pulley-gear-unit-40-m1-25-16t-bore8/pulley-gear-unit-40-m1-25-16t-bore8.stl",
   "note": "unit, axis Z, pulley z 0..16, gear z 16..24, a tooth on +X"
  }
 ],
 "markdown": "https://xemstudio.com/objects/pulley-gear-unit-40-m1-25-16t-bore8/index.md"
}