{
 "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": "list-test-tube-marble-engine",
 "name": "Build list: Test-tube marble engine",
 "kind": "list",
 "category": "Stirling engines",
 "group": "Guide",
 "year": null,
 "question": "What parts do I need to build a test-tube marble Stirling engine?",
 "tags": [
  "list",
  "build",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "test tube stirling engine",
  "marble stirling engine",
  "test tube marble engine parts list",
  "marble displacer stirling"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "not-scanned",
 "les": true,
 "free_files": 0,
 "url": "https://xemstudio.com/objects/list-test-tube-marble-engine/",
 "sheet_txt": "https://xemstudio.com/objects/list-test-tube-marble-engine/sheet.txt",
 "sheet": {
  "basis": "Every part is a free file on this site.",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "crank and flywheel at the end.",
   "Numbers: 25 × 150 tube · 4 marbles Ø15.875 (5/8 in) · 5 mL glass syringe, plunger travel 2.1..16.6 out · rocker -7.9..7.9° · rocking pin 90° ahead · Ø100 flywheel crank · both cranks overhung"
  ],
  "table": {
   "columns": [
    "subsystem",
    "object",
    "parts",
    "qty",
    "note"
   ],
   "rows": [
    [
     "Base",
     "marble-engine-base",
     "marble-engine-base",
     1,
     ""
    ],
    [
     "Pivot posts",
     "beam-pivot-post",
     "pivot-post-60",
     2,
     "y ±10"
    ],
    [
     "Pivot pin",
     "dowel-pins-metric",
     "dowel-3x30",
     1,
     "through both posts and the rocker hub"
    ],
    [
     "Rocker",
     "marble-engine-rocker",
     "marble-engine-rocker-25x150-glass5",
     1,
     ""
    ],
    [
     "Displacer cylinder",
     "borosilicate-test-tubes",
     "test-tube-25x150",
     1,
     "closed end is the hot end"
    ],
    [
     "Displacer",
     "glass-marbles",
     "marble-5-8in",
     4,
     "roll end to end as it rocks"
    ],
    [
     "Stopper",
     "rubber-stoppers",
     "stopper-4-bore-4",
     1,
     "#4 bored Ø4 for the 4 mm tube"
    ],
    [
     "Transfer tube",
     "brass-tube-ks",
     "brass-4mm",
     1,
     "through the stopper"
    ],
    [
     "Transfer hose",
     "silicone-tube",
     "silicone-tube-4x6-50",
     1,
     "4 mm tube to Luer cone, straight"
    ],
    [
     "Power cylinder",
     "glass-syringes",
     "glass-syringe-5ml-barrel",
     1,
     "in the rocker's ring"
    ],
    [
     "Power piston",
     "glass-syringes",
     "glass-syringe-5ml-plunger",
     1,
     ""
    ],
    [
     "Plunger clevis",
     "glass-syringe-plunger-clevis",
     "plunger-clevis-glass-5ml",
     1,
     ""
    ],
    [
     "Crank stands",
     "can-engine-crank-stand",
     "crank-stand-80",
     2,
     "623 pockets, axis 80 above the base"
    ],
    [
     "Bearings",
     "ball-bearings-metric",
     "bearing-623",
     2,
     ""
    ],
    [
     "Crankshaft",
     "stirling-crankshafts",
     "crankshaft-3x60",
     1,
     "along y, both cranks overhung"
    ],
    [
     "Power crank",
     "crank-discs-3mm-bore",
     "crank-disc-b3-stroke15",
     1,
     "syringe end"
    ],
    [
     "Flywheel crank",
     "flywheel-crank",
     "flywheel-crank-100-m8-b3-s15",
     1,
     "rocking end, its pin 90° ahead of the power pin"
    ],
    [
     "Flywheel weights",
     "hex-nut-weights",
     "nut-m8",
     6,
     "alternate pockets"
    ],
    [
     "Con-rod",
     "pin-end-con-rods",
     "conrod-45",
     1,
     "power pin to plunger clevis"
    ],
    [
     "Rocking link",
     "marble-engine-rocking-link",
     "rocking-link-170",
     1,
     "flywheel-crank pin to the lever pin"
    ],
    [
     "Crank pin (flywheel)",
     "dowel-pins-metric",
     "dowel-3x16",
     1,
     "10 in the hub, through the link, 1 proud"
    ],
    [
     "Pins",
     "dowel-pins-metric",
     "dowel-3x12",
     3,
     "power crank pin, clevis pin, lever pin"
    ],
    [
     "Post screws",
     "socket-head-cap-screws-metric",
     "shcs-m3x12",
     4,
     ""
    ],
    [
     "Stand screws",
     "socket-head-cap-screws-metric",
     "shcs-m3x10",
     4,
     ""
    ],
    [
     "Nuts",
     "hex-nuts-metric",
     "nut-m3",
     8,
     "in the base's pockets"
    ],
    [
     "Grub screws",
     "set-screws-metric",
     "set-m3x4",
     2,
     "tube ring and syringe ring"
    ],
    [
     "Grub screw",
     "set-screws-metric",
     "set-m3x10",
     1,
     "power crank disc"
    ],
    [
     "Grub screw",
     "set-screws-metric",
     "set-m3x8",
     1,
     "flywheel-crank hub"
    ],
    [
     "Grub screw",
     "set-screws-metric",
     "set-m3x3",
     1,
     "plunger clevis"
    ],
    [
     "Heat",
     "tea-light-candles",
     "tea-light-38x16",
     1,
     "optional: under the closed end"
    ]
   ]
  }
 },
 "sheet_text": "Build list: Test-tube marble engine — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/list-test-tube-marble-engine/  (CC BY 4.0)\nBasis: Every part is a free file on this site.\nCatalog version: 2026-10-20\n\nSizes: see table below\n- crank and flywheel at the end.\n- Numbers: 25 × 150 tube · 4 marbles Ø15.875 (5/8 in) · 5 mL glass syringe, plunger travel 2.1..16.6 out · rocker -7.9..7.9° · rocking pin 90° ahead · Ø100 flywheel crank · both cranks overhung\n\nsubsystem  object  parts  qty  note\nBase  marble-engine-base  marble-engine-base  1  \nPivot posts  beam-pivot-post  pivot-post-60  2  y ±10\nPivot pin  dowel-pins-metric  dowel-3x30  1  through both posts and the rocker hub\nRocker  marble-engine-rocker  marble-engine-rocker-25x150-glass5  1  \nDisplacer cylinder  borosilicate-test-tubes  test-tube-25x150  1  closed end is the hot end\nDisplacer  glass-marbles  marble-5-8in  4  roll end to end as it rocks\nStopper  rubber-stoppers  stopper-4-bore-4  1  #4 bored Ø4 for the 4 mm tube\nTransfer tube  brass-tube-ks  brass-4mm  1  through the stopper\nTransfer hose  silicone-tube  silicone-tube-4x6-50  1  4 mm tube to Luer cone, straight\nPower cylinder  glass-syringes  glass-syringe-5ml-barrel  1  in the rocker's ring\nPower piston  glass-syringes  glass-syringe-5ml-plunger  1  \nPlunger clevis  glass-syringe-plunger-clevis  plunger-clevis-glass-5ml  1  \nCrank stands  can-engine-crank-stand  crank-stand-80  2  623 pockets, axis 80 above the base\nBearings  ball-bearings-metric  bearing-623  2  \nCrankshaft  stirling-crankshafts  crankshaft-3x60  1  along y, both cranks overhung\nPower crank  crank-discs-3mm-bore  crank-disc-b3-stroke15  1  syringe end\nFlywheel crank  flywheel-crank  flywheel-crank-100-m8-b3-s15  1  rocking end, its pin 90° ahead of the power pin\nFlywheel weights  hex-nut-weights  nut-m8  6  alternate pockets\nCon-rod  pin-end-con-rods  conrod-45  1  power pin to plunger clevis\nRocking link  marble-engine-rocking-link  rocking-link-170  1  flywheel-crank pin to the lever pin\nCrank pin (flywheel)  dowel-pins-metric  dowel-3x16  1  10 in the hub, through the link, 1 proud\nPins  dowel-pins-metric  dowel-3x12  3  power crank pin, clevis pin, lever pin\nPost screws  socket-head-cap-screws-metric  shcs-m3x12  4  \nStand screws  socket-head-cap-screws-metric  shcs-m3x10  4  \nNuts  hex-nuts-metric  nut-m3  8  in the base's pockets\nGrub screws  set-screws-metric  set-m3x4  2  tube ring and syringe ring\nGrub screw  set-screws-metric  set-m3x10  1  power crank disc\nGrub screw  set-screws-metric  set-m3x8  1  flywheel-crank hub\nGrub screw  set-screws-metric  set-m3x3  1  plunger clevis\nHeat  tea-light-candles  tea-light-38x16  1  optional: under the closed end\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/\n\nXem Studio scan: not planned; the official CAD above covers it.\nAPI: https://xemstudio.com/api/geometry?object=list-test-tube-marble-engine\n",
 "sources": [
  {
   "publisher": "Long Earth Society",
   "title": "Engine builds",
   "url": "https://longearthsociety.com/engineering/",
   "formats": [
    "web",
    "video"
   ],
   "license": "LES site",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "not-scanned",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "marble-engine-rocker",
  "borosilicate-test-tubes",
  "glass-marbles",
  "glass-syringes",
  "rubber-stoppers"
 ],
 "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 parts do I need to build a test-tube marble Stirling engine?",
   "a": "30 parts, every one a free STEP/STL on this site; see the table and the build order on this page."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/list-test-tube-marble-engine/index.md"
}