{
 "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": "stepped-cone-pulley-50-40-30",
 "name": "Stepped (speed-cone) pulley Ø50 / Ø40 / Ø30 × 20 mm steps, Ø8 bore",
 "kind": "modern",
 "category": "Hardware",
 "group": "Mechanism parts",
 "year": null,
 "question": "What is a stepped cone pulley?",
 "tags": [
  "mechanism part",
  "507 mechanical movements"
 ],
 "aliases": [
  "cone pulley",
  "step pulley",
  "speed cone",
  "lathe step pulley",
  "polea escalonada (cono de poleas)",
  "Stufenscheibe"
 ],
 "overall_mm": {
  "length": 50,
  "width": 50,
  "height": 60
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/stepped-cone-pulley-50-40-30/",
 "sheet_txt": "https://xemstudio.com/objects/stepped-cone-pulley-50-40-30/sheet.txt",
 "sheet": {
  "basis": "Xem Studio design following Brown's figure (1868); true size, no printing allowance",
  "overall_mm": {
   "length": 50,
   "width": 50,
   "height": 60
  },
  "notes": [
   "Three flat-belt steps Ø50, Ø40 and Ø30, each 20 mm wide (60 mm total), Ø8 bore. Two identical cones mounted the opposite way round keep the same belt length on each step pair (the diameters sum to 80 every time).",
   "Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features)."
  ],
  "table": {
   "columns": [
    "dimension",
    "value"
   ],
   "rows": [
    [
     "steps",
     "Ø50 / Ø40 / Ø30"
    ],
    [
     "step width",
     "20 mm"
    ],
    [
     "bore",
     "Ø8"
    ]
   ]
  }
 },
 "sheet_text": "Stepped (speed-cone) pulley Ø50 / Ø40 / Ø30 × 20 mm steps, Ø8 bore — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/stepped-cone-pulley-50-40-30/  (CC BY 4.0)\nBasis: Xem Studio design following Brown's figure (1868); true size, no printing allowance\nCatalog version: 2026-10-20\n\nOverall (mm): length 50.0, width 50.0, height 60.0\n- Three flat-belt steps Ø50, Ø40 and Ø30, each 20 mm wide (60 mm total), Ø8 bore. Two identical cones mounted the opposite way round keep the same belt length on each step pair (the diameters sum to 80 every time).\n- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).\n\ndimension  value\nsteps  Ø50 / Ø40 / Ø30\nstep width  20 mm\nbore  Ø8\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. 8: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_008.html\n- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/stepped-cone-pulleys-mechanism/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/stepped-cone-pulley-50-40-30/index.json\nAPI: https://xemstudio.com/api/geometry?object=stepped-cone-pulley-50-40-30\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. 8: figure, his text and an animation",
   "url": "https://507movements.com/mm_008.html",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Xem Studio",
   "title": "drawing",
   "url": "https://xemstudio.com/objects/stepped-cone-pulleys-mechanism/",
   "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": [
  "stepped-cone-pulleys-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 stepped cone pulley?",
   "a": "Three flat-belt steps Ø50, Ø40 and Ø30, each 20 mm wide (60 mm total), Ø8 bore. Two identical cones mounted the opposite way round keep the same belt length on each step pair (the diameters sum to 80 every time)."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "stepped-cone-pulley-50-40-30",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/stepped-cone-pulley-50-40-30/stepped-cone-pulley-50-40-30.step",
   "stl": "https://xemstudio.com/files/hardware/stepped-cone-pulley-50-40-30/stepped-cone-pulley-50-40-30.stl",
   "note": "pulley, axis Z, Ø50 step at z 0..20"
  }
 ],
 "markdown": "https://xemstudio.com/objects/stepped-cone-pulley-50-40-30/index.md"
}