{
 "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": "belt-shifted-gears-three-speed-mechanism",
 "name": "Three speeds by shifting a belt over pulleys carrying gears (16 / 24 / 32 T)",
 "kind": "hardware",
 "category": "Mechanisms",
 "group": "Gears",
 "year": null,
 "question": "How does shifting a belt along pulley-gear units give three speeds?",
 "tags": [
  "mechanism",
  "gears",
  "kinematics",
  "507 mechanical movements"
 ],
 "aliases": [
  "three speed belt gear",
  "gear change by belt",
  "pulley gear speed change",
  "tres velocidades con correa y engranajes",
  "Dreigang mit Riemen und Zahnrädern"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/belt-shifted-gears-three-speed-mechanism/",
 "sheet_txt": "https://xemstudio.com/objects/belt-shifted-gears-three-speed-mechanism/sheet.txt",
 "sheet": {
  "basis": "Xem Studio design following Brown No. 58 (1868)",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "On the input shaft run loose units each made of a pulley and a gear (16, 24 and 32 teeth) and an idle pulley; the gears mesh with a cluster of 32, 24 and 16 teeth fixed on the output shaft 30 mm away. The belt drives whichever unit it is on: output speed 16/32, 24/24 or 32/16 of the input pulley's — or nothing on the idler.",
   "Module 1.25 throughout (N₁ + N₂ = 48 keeps one 30 mm centre distance); belt from a wide Ø40 driving pulley 140 mm above, drawn on the 24-tooth unit (1 : 1). Speeds: 0.5, 1, 2 × input.",
   "Brown's No. 58 (three speeds from a belt shifted across four pulleys carrying spur gears).",
   "Parts (each has its own page): pulley-gear-unit-40-m1-25-16t-bore8, pulley-gear-unit-40-m1-25-24t-bore8, pulley-gear-unit-40-m1-25-32t-bore8, gear-cluster-m1-25-32-24-16-bore8, plain-flat-pulley-40x16, plain-flat-pulley-40x100, flat-belt-16x1-5-pulleys-40-40-c140, linear-shafts-h6.",
   "Brown's movement No. 58 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size."
  ],
  "table": {
   "columns": [
    "parameter",
    "value"
   ],
   "rows": [
    [
     "units",
     "Ø40 pulleys with 16 / 24 / 32 T gears, module 1.25"
    ],
    [
     "cluster",
     "32 / 24 / 16 T"
    ],
    [
     "speeds",
     "0.5, 1, 2 × input, or stop"
    ],
    [
     "centres",
     "30 mm"
    ]
   ]
  }
 },
 "sheet_text": "Three speeds by shifting a belt over pulleys carrying gears (16 / 24 / 32 T) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/belt-shifted-gears-three-speed-mechanism/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)\nBasis: Xem Studio design following Brown No. 58 (1868)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- On the input shaft run loose units each made of a pulley and a gear (16, 24 and 32 teeth) and an idle pulley; the gears mesh with a cluster of 32, 24 and 16 teeth fixed on the output shaft 30 mm away. The belt drives whichever unit it is on: output speed 16/32, 24/24 or 32/16 of the input pulley's — or nothing on the idler.\n- Module 1.25 throughout (N₁ + N₂ = 48 keeps one 30 mm centre distance); belt from a wide Ø40 driving pulley 140 mm above, drawn on the 24-tooth unit (1 : 1). Speeds: 0.5, 1, 2 × input.\n- Brown's No. 58 (three speeds from a belt shifted across four pulleys carrying spur gears).\n- Parts (each has its own page): pulley-gear-unit-40-m1-25-16t-bore8, pulley-gear-unit-40-m1-25-24t-bore8, pulley-gear-unit-40-m1-25-32t-bore8, gear-cluster-m1-25-32-24-16-bore8, plain-flat-pulley-40x16, plain-flat-pulley-40x100, flat-belt-16x1-5-pulleys-40-40-c140, linear-shafts-h6.\n- Brown's movement No. 58 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.\n\nparameter  value\nunits  Ø40 pulleys with 16 / 24 / 32 T gears, module 1.25\ncluster  32 / 24 / 16 T\nspeeds  0.5, 1, 2 × input, or stop\ncentres  30 mm\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. 58: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_058.html\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/belt-shifted-gears-three-speed-mechanism/index.json\nAPI: https://xemstudio.com/api/geometry?object=belt-shifted-gears-three-speed-mechanism\n",
 "sources": [
  {
   "publisher": "Henry T. Brown (1868, public domain)",
   "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. 58: figure, his text and an animation",
   "url": "https://507movements.com/mm_058.html",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "pulley-gear-unit-40-m1-25-16t-bore8",
  "pulley-gear-unit-40-m1-25-24t-bore8",
  "pulley-gear-unit-40-m1-25-32t-bore8",
  "gear-cluster-m1-25-32-24-16-bore8",
  "plain-flat-pulley-40x16",
  "plain-flat-pulley-40x100",
  "flat-belt-16x1-5-pulleys-40-40-c140",
  "linear-shafts-h6"
 ],
 "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": "How does shifting a belt along pulley-gear units give three speeds?",
   "a": "On the input shaft run loose units each made of a pulley and a gear (16, 24 and 32 teeth) and an idle pulley; the gears mesh with a cluster of 32, 24 and 16 teeth fixed on the output shaft 30 mm away. The belt drives whichever unit it is on: output speed 16/32, 24/24 or 32/16 of the input pulley's — or nothing on the idler."
  }
 ],
 "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."
 },
 "offers": [
  {
   "file": "belt-shifted-gears-three-speed-mechanism-assembly",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/belt-shifted-gears-three-speed-mechanism/belt-shifted-gears-three-speed-mechanism-assembly.step",
   "stl": "https://xemstudio.com/files/hardware/belt-shifted-gears-three-speed-mechanism/belt-shifted-gears-three-speed-mechanism-assembly.stl",
   "note": "Assembled mechanism, all parts placed at one pose (STEP keeps each part separate)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/belt-shifted-gears-three-speed-mechanism/index.md"
}