{
 "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": "reversing-groove-drum-30x90-p30",
 "name": "Reversing-groove drum Ø30 × 90: crossed right- and left-hand grooves, pitch 30, 5 wide",
 "kind": "modern",
 "category": "Hardware",
 "group": "Mechanism parts",
 "year": null,
 "question": "What is a reversing screw drum?",
 "tags": [
  "mechanism part",
  "507 mechanical movements"
 ],
 "aliases": [
  "level wind drum",
  "reversing screw",
  "diamond screw",
  "double thread drum",
  "tambor de ranura cruzada",
  "Kreuzgewindewalze (Kehrgewinde)"
 ],
 "overall_mm": {
  "length": 30,
  "width": 30,
  "height": 90
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/reversing-groove-drum-30x90-p30/",
 "sheet_txt": "https://xemstudio.com/objects/reversing-groove-drum-30x90-p30/sheet.txt",
 "sheet": {
  "basis": "Xem Studio design following Brown's figure (1868); true size, no printing allowance",
  "overall_mm": {
   "length": 30,
   "width": 30,
   "height": 90
  },
  "notes": [
   "Ø30 × 90 cylinder (Ø5 bore) with two 5 mm wide, 3 mm deep grooves cut over the middle 60 mm: one right-hand and one left-hand helix of 30 mm pitch (two turns each), crossing each other at 180° and meeting at 0°. Each groove is 5 mm wide measured square to its path at the bottom (5.38 mm axially; helicoid flanks, 0.17 mm wider at the surface). A Ø5 pin in the groove runs 60 mm up in two turns of the drum, turns the corner and runs 60 mm back in the next two.",
   "The level-wind (fishing reel, winch) drum: the turn-around is drawn as the sharp meeting of the two helices; a real traverser carries a keel-shaped shoe that is steered round it.",
   "Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features)."
  ],
  "table": {
   "columns": [
    "dimension",
    "value"
   ],
   "rows": [
    [
     "drum",
     "Ø30 × 90 mm"
    ],
    [
     "grooves",
     "RH + LH, pitch 30, 2 turns each"
    ],
    [
     "groove",
     "5 wide × 3 deep"
    ],
    [
     "traverse",
     "60 mm per 2 turns"
    ],
    [
     "bore",
     "Ø5"
    ]
   ]
  }
 },
 "sheet_text": "Reversing-groove drum Ø30 × 90: crossed right- and left-hand grooves, pitch 30, 5 wide — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/reversing-groove-drum-30x90-p30/  (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 30.0, width 30.0, height 90.0\n- Ø30 × 90 cylinder (Ø5 bore) with two 5 mm wide, 3 mm deep grooves cut over the middle 60 mm: one right-hand and one left-hand helix of 30 mm pitch (two turns each), crossing each other at 180° and meeting at 0°. Each groove is 5 mm wide measured square to its path at the bottom (5.38 mm axially; helicoid flanks, 0.17 mm wider at the surface). A Ø5 pin in the groove runs 60 mm up in two turns of the drum, turns the corner and runs 60 mm back in the next two.\n- The level-wind (fishing reel, winch) drum: the turn-around is drawn as the sharp meeting of the two helices; a real traverser carries a keel-shaped shoe that is steered round it.\n- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).\n\ndimension  value\ndrum  Ø30 × 90 mm\ngrooves  RH + LH, pitch 30, 2 turns each\ngroove  5 wide × 3 deep\ntraverse  60 mm per 2 turns\nbore  Ø5\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. 108: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_108.html\n- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/reversing-screw-traverse-mechanism/\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/reversing-groove-drum-30x90-p30/index.json\nAPI: https://xemstudio.com/api/geometry?object=reversing-groove-drum-30x90-p30\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. 108: figure, his text and an animation",
   "url": "https://507movements.com/mm_108.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/reversing-screw-traverse-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": [
  "reversing-screw-traverse-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 reversing screw drum?",
   "a": "Ø30 × 90 cylinder (Ø5 bore) with two 5 mm wide, 3 mm deep grooves cut over the middle 60 mm: one right-hand and one left-hand helix of 30 mm pitch (two turns each), crossing each other at 180° and meeting at 0°. Each groove is 5 mm wide measured square to its path at the bottom (5.38 mm axially; helicoid flanks, 0.17 mm wider at the surface). A Ø5 pin in the groove runs 60 mm up in two turns of the drum, turns the corner and runs 60 mm back in the next two."
  }
 ],
 "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": "reversing-groove-drum-30x90",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/reversing-groove-drum-30x90-p30/reversing-groove-drum-30x90.step",
   "stl": "https://xemstudio.com/files/hardware/reversing-groove-drum-30x90-p30/reversing-groove-drum-30x90.stl",
   "note": "drum, axis Z, grooves z 15..75, both start at angle 0"
  }
 ],
 "markdown": "https://xemstudio.com/objects/reversing-groove-drum-30x90-p30/index.md"
}