{
 "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": "glass-syringe-plunger-clevis",
 "name": "Plunger clevis for a glass syringe: cap over the piston collar with a con-rod fork",
 "kind": "hardware",
 "category": "Hardware",
 "group": "Stirling & thermoacoustic",
 "year": null,
 "question": "How do I connect a crank to a glass syringe plunger?",
 "tags": [
  "clevis",
  "syringe",
  "glass syringe",
  "con-rod",
  "fork",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "glass syringe plunger connector",
  "syringe plunger con rod",
  "syringe piston clevis",
  "connect syringe to crank"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 2,
 "url": "https://xemstudio.com/objects/glass-syringe-plunger-clevis/",
 "sheet_txt": "https://xemstudio.com/objects/glass-syringe-plunger-clevis/sheet.txt",
 "sheet": {
  "basis": "My geometry, drawn to the glass syringe's published piston collar (KD Scientific / Tomopal: 5 mL Ø17.25, 10 mL Ø19.95); fork sized for the 5 mm thick pin-end con-rods",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "The cap's pocket is the piston collar's published diameter, exactly (5 mL Ø17.25, 10 mL Ø19.95), 3 deep (the collar thickness drawn on the plunger file; the datasheet gives no thickness). One M3 grub (set-m3x3) in a Ø2.5 tapped hole reaches the collar's edge; the cap's top face pushes on the collar.",
   "Fork: 12 × 12 block, 5 mm slot for a 5 mm con-rod, Ø3 pin hole 12 above the collar underside, for a dowel-3x12 (flush both sides).",
   "Used on the mug LTD and the test-tube marble engine (5 mL)."
  ],
  "table": {
   "columns": [
    "part",
    "pocket_mm",
    "body_mm",
    "pin_above_collar_mm",
    "pin"
   ],
   "rows": [
    [
     "plunger-clevis-glass-5ml",
     17.25,
     23.25,
     12,
     "Ø3 (dowel-3x12)"
    ],
    [
     "plunger-clevis-glass-10ml",
     19.95,
     25.95,
     12,
     "Ø3 (dowel-3x12)"
    ]
   ]
  }
 },
 "sheet_text": "Plunger clevis for a glass syringe: cap over the piston collar with a con-rod fork — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/glass-syringe-plunger-clevis/  (CC BY 4.0)\nBasis: My geometry, drawn to the glass syringe's published piston collar (KD Scientific / Tomopal: 5 mL Ø17.25, 10 mL Ø19.95); fork sized for the 5 mm thick pin-end con-rods\nCatalog version: 2026-10-20\n\nSizes: see table below\n- The cap's pocket is the piston collar's published diameter, exactly (5 mL Ø17.25, 10 mL Ø19.95), 3 deep (the collar thickness drawn on the plunger file; the datasheet gives no thickness). One M3 grub (set-m3x3) in a Ø2.5 tapped hole reaches the collar's edge; the cap's top face pushes on the collar.\n- Fork: 12 × 12 block, 5 mm slot for a 5 mm con-rod, Ø3 pin hole 12 above the collar underside, for a dowel-3x12 (flush both sides).\n- Used on the mug LTD and the test-tube marble engine (5 mL).\n\npart  pocket_mm  body_mm  pin_above_collar_mm  pin\nplunger-clevis-glass-5ml  17.25  23.25  12.0  Ø3 (dowel-3x12)\nplunger-clevis-glass-10ml  19.95  25.95  12.0  Ø3 (dowel-3x12)\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- KD Scientific: Full Line of Glass Syringes, rev. A (order codes 78-0871 to 78-0880): piston OD, barrel OD D1, barrel collar D2, piston collar D3, length L — PDF — manufacturer datasheet [verify license at link] — https://www.kdscientific.com/media/brochures/KDS%20Glass%20Syringe%20Datasheet.pdf\n- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 2 parts): https://xemstudio.com/files/hardware/glass-syringe-plunger-clevis/index.json\nAPI: https://xemstudio.com/api/geometry?object=glass-syringe-plunger-clevis\n",
 "sources": [
  {
   "publisher": "KD Scientific",
   "title": "Full Line of Glass Syringes, rev. A (order codes 78-0871 to 78-0880): piston OD, barrel OD D1, barrel collar D2, piston collar D3, length L",
   "url": "https://www.kdscientific.com/media/brochures/KDS%20Glass%20Syringe%20Datasheet.pdf",
   "formats": [
    "PDF"
   ],
   "license": "manufacturer datasheet",
   "license_verified": false,
   "hosted": false
  },
  {
   "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": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "glass-syringes",
  "pin-end-con-rods",
  "dowel-pins-metric",
  "set-screws-metric",
  "list-ltd-mug",
  "list-test-tube-marble-engine"
 ],
 "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": [
  {
   "feature": "collar pocket",
   "exact": "Ø17.25 × 3 (5 mL) / Ø19.95 × 3 (10 mL)",
   "mates": "glass piston collar",
   "fit": "slide",
   "files": "plunger-clevis-"
  },
  {
   "feature": "grub hole",
   "exact": "Ø2.5 (M3 tapped)",
   "mates": "set-m3x3",
   "fit": "designed",
   "files": "plunger-clevis-"
  },
  {
   "feature": "fork slot",
   "exact": "5",
   "mates": "5 mm con-rod",
   "fit": "run",
   "files": "plunger-clevis-"
  },
  {
   "feature": "pin hole",
   "exact": "Ø3",
   "mates": "dowel-3x12",
   "fit": "press",
   "files": "plunger-clevis-"
  }
 ],
 "fit_classes": {
  "press": "stays put: pin, tube, bearing or magnet held by interference. Typical FDM: hole +0.0 to +0.1 mm on diameter.",
  "slide": "assembles by hand and is held by a grub, pinch or clamp: shaft in a hub, rod in a socket, spigot in a bore. Typical FDM: +0.2 mm.",
  "run": "turns or slides in use: pin in a link, rod through a guide. Typical FDM: +0.3 mm.",
  "socket": "large sliding fit: syringe barrel, sleeve, bobbin in a bore. Typical FDM: +0.3 mm.",
  "clamp": "split part that closes on the mating part with screws: make it at size.",
  "designed": "a gap that is part of the design (piston fit option, displacer gap, air gap): do not change."
 },
 "faq": [
  {
   "q": "How does the con-rod attach to a glass syringe plunger?",
   "a": "Through this cap: it sits over the plunger's collar (pocket at the collar's exact Ø), an M3 grub holds it, and a Ø3 pin through its fork carries the con-rod's small end."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "plunger-clevis-glass-5ml",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/glass-syringe-plunger-clevis/plunger-clevis-glass-5ml.step",
   "stl": "https://xemstudio.com/files/hardware/glass-syringe-plunger-clevis/plunger-clevis-glass-5ml.stl",
   "note": "cap for the 5 mL glass plunger: Ø17.25 × 3 pocket (the piston collar, exact), Ø23.25 body, M3 tapped (Ø2.5) grub to the collar edge, 12 × 12 fork with a 5 mm slot and a Ø3 pin hole 12 above the collar's underside"
  },
  {
   "file": "plunger-clevis-glass-10ml",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/glass-syringe-plunger-clevis/plunger-clevis-glass-10ml.step",
   "stl": "https://xemstudio.com/files/hardware/glass-syringe-plunger-clevis/plunger-clevis-glass-10ml.stl",
   "note": "cap for the 10 mL glass plunger: Ø19.95 × 3 pocket (the piston collar, exact), Ø25.95 body, M3 tapped (Ø2.5) grub to the collar edge, 12 × 12 fork with a 5 mm slot and a Ø3 pin hole 12 above the collar's underside"
  }
 ],
 "markdown": "https://xemstudio.com/objects/glass-syringe-plunger-clevis/index.md"
}