{ "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-pulleys-mechanism", "name": "Stepped cone pulleys (three speeds by moving the belt)", "kind": "hardware", "category": "Mechanisms", "group": "Belt and friction drives", "year": null, "question": "How do stepped cone pulleys change speed?", "tags": [ "mechanism", "belt and friction drives", "kinematics", "507 mechanical movements" ], "aliases": [ "cone pulleys", "step pulleys", "speed cone pulleys", "poleas escalonadas", "Stufenscheibentrieb" ], "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/stepped-cone-pulleys-mechanism/", "sheet_txt": "https://xemstudio.com/objects/stepped-cone-pulleys-mechanism/sheet.txt", "sheet": { "basis": "Xem Studio design following Brown No. 8 (1868)", "overall_mm": { "length": null, "width": null, "height": null }, "notes": [ "Two identical stepped pulleys mounted head to tail: moving the belt from one step pair to another changes the speed ratio — 50/30 = 1.67, 40/40 = 1, 30/50 = 0.6 — while the belt length stays the same because each pair's diameters add to 80 mm.", "Drawn with the belt on the middle (Ø40 / Ø40) steps, shafts 120 mm apart; belt inside length 365.66 mm.", "Brown's No. 8 (speed pulleys); the classic lathe and drill-press drive.", "Parts (each has its own page): stepped-cone-pulley-50-40-30, flat-belt-1-5x16-pulleys-40-120.", "Brown's movement No. 8 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size." ], "table": { "columns": [ "parameter", "value" ], "rows": [ [ "steps", "Ø50 / Ø40 / Ø30 (×2, reversed)" ], [ "ratios", "1.67, 1, 0.6" ], [ "shaft centres", "120 mm" ], [ "belt", "16 × 1.5 flat" ] ] } }, "sheet_text": "Stepped cone pulleys (three speeds by moving the belt) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/stepped-cone-pulleys-mechanism/ (CC BY 4.0)\nBasis: Xem Studio design following Brown No. 8 (1868)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Two identical stepped pulleys mounted head to tail: moving the belt from one step pair to another changes the speed ratio — 50/30 = 1.67, 40/40 = 1, 30/50 = 0.6 — while the belt length stays the same because each pair's diameters add to 80 mm.\n- Drawn with the belt on the middle (Ø40 / Ø40) steps, shafts 120 mm apart; belt inside length 365.66 mm.\n- Brown's No. 8 (speed pulleys); the classic lathe and drill-press drive.\n- Parts (each has its own page): stepped-cone-pulley-50-40-30, flat-belt-1-5x16-pulleys-40-120.\n- Brown's movement No. 8 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.\n\nparameter value\nsteps Ø50 / Ø40 / Ø30 (×2, reversed)\nratios 1.67, 1, 0.6\nshaft centres 120 mm\nbelt 16 × 1.5 flat\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\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/stepped-cone-pulleys-mechanism/index.json\nAPI: https://xemstudio.com/api/geometry?object=stepped-cone-pulleys-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. 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 } ], "xem": { "status": "free-files", "sheet_free": true, "mesh_price_usd": null, "step_price_usd": null, "tolerance_mm": null }, "related": [ "stepped-cone-pulley-50-40-30", "flat-belt-1-5x16-pulleys-40-120" ], "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 do stepped cone pulleys change speed?", "a": "Two identical stepped pulleys mounted head to tail: moving the belt from one step pair to another changes the speed ratio — 50/30 = 1.67, 40/40 = 1, 30/50 = 0.6 — while the belt length stays the same because each pair's diameters add to 80 mm." } ], "files_license": null, "offers": [ { "file": "stepped-cone-pulleys-mechanism-assembly", "formats": [ "step", "stl" ], "price_usd": 0, "license": "CC BY 4.0 (Xem Studio)", "step": "https://xemstudio.com/files/hardware/stepped-cone-pulleys-mechanism/stepped-cone-pulleys-mechanism-assembly.step", "stl": "https://xemstudio.com/files/hardware/stepped-cone-pulleys-mechanism/stepped-cone-pulleys-mechanism-assembly.stl", "note": "Assembled mechanism, all parts placed at one pose (STEP keeps each part separate)" } ], "markdown": "https://xemstudio.com/objects/stepped-cone-pulleys-mechanism/index.md" }