{
 "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-tri-clamp-cross-diaphragm-gamma",
 "name": "Build list: Tri-clamp cross diaphragm gamma, 2 in",
 "kind": "list",
 "category": "Stirling engines",
 "group": "Guide",
 "year": null,
 "question": "What parts do I need to build a Tri-clamp cross diaphragm gamma, 2 in?",
 "tags": [
  "list",
  "build",
  "stirling",
  "long earth society",
  "tri-clamp",
  "diaphragm",
  "gamma",
  "cross",
  "fast"
 ],
 "aliases": [
  "tri clamp cross stirling",
  "diaphragm gamma cross crankcase",
  "fast stirling engine tri clamp",
  "sealed crankcase stirling",
  "tri clamp stirling build list"
 ],
 "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-tri-clamp-cross-diaphragm-gamma/",
 "sheet_txt": "https://xemstudio.com/objects/list-tri-clamp-cross-diaphragm-gamma/sheet.txt",
 "sheet": {
  "basis": "Every part is a free STEP/STL on this site or a standard part with its own page; quantities are the full count, every screw, nut, pin, gasket and clamp.",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "A fast gamma in 2 in tri-clamp: a hot cap and short spool over a torch, a cross as the sealed crankcase with the crank inside it, a diaphragm on top and a thin crankshaft out through a long bore to the flywheel.",
   "Numbers: Diaphragm 2 in at 12 mm: 11.3 mL swept · displacer Ø46 × 60 at 12 mm: 19.9 mL swept · dead volume 68.1 mL · swept / dead 0.166"
  ],
  "table": {
   "columns": [
    "subsystem",
    "object",
    "parts",
    "qty",
    "note"
   ],
   "rows": [
    [
     null,
     "tri-clamp-cross-engine-frame",
     "cross-engine-frame-2in",
     1,
     "base, wall, gussets"
    ],
    [
     null,
     "tri-clamp-torch-stand",
     "torch-stand-40",
     1,
     "on the base under the hot cap, post toward the front"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m4x10",
     2,
     "torch stand to the base"
    ],
    [
     null,
     "set-screws-metric",
     "set-m4x10",
     3,
     "centre the torch head in the stand ring"
    ],
    [
     null,
     "tri-clamp-end-cap",
     "tc-cap-2in-flat",
     2,
     "hot cap (face up, over the flame) and the +X branch"
    ],
    [
     null,
     "tri-clamp-hot-gasket",
     "hot-gasket-2in",
     1,
     "hot joint"
    ],
    [
     null,
     "tri-clamp-heat-shield",
     "heat-shield-2in",
     1,
     "on the hot clamp"
    ],
    [
     null,
     "tri-clamp-spool",
     "tc-spool-2in-3in",
     1,
     "hot cylinder with the cap: displacer inside"
    ],
    [
     null,
     "tri-clamp-jacket-shell",
     "jacket-half-2in-56",
     2,
     "band round the hot spool; the fill is the builder's choice"
    ],
    [
     null,
     "tri-clamp-jacket-shell",
     "jacket-port-cap",
     2,
     "one per jacket half"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m4x30",
     4,
     "jacket ears"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m4",
     6,
     "jacket ears (4), hanger ears (2)"
    ],
    [
     null,
     "sanitary-clamp-crosses",
     "cross-2in",
     1,
     "the crankcase: run vertical, branches along the crankshaft"
    ],
    [
     null,
     "tri-clamp-gasket",
     "tc-gasket-2in",
     3,
     "spool–cross, end cap, bearing cap"
    ],
    [
     null,
     "tri-clamp-clamps",
     "clamp-half-2in",
     10,
     "five joints, two halves each"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m5x30",
     10,
     "clamp bolts"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m5",
     12,
     "clamp nuts (10), hanger bar (2)"
    ],
    [
     null,
     "tri-clamp-cross-crankcase-insert",
     "crankcase-insert-2in",
     1,
     "fills the run; Ø3 displacer-rod guide; crank chamber"
    ],
    [
     null,
     "tri-clamp-cross-branch-plug",
     "branch-plug-2in-blind",
     1,
     "end-cap branch"
    ],
    [
     null,
     "tri-clamp-cross-branch-plug",
     "branch-plug-2in-bore16",
     1,
     "bearing-cap branch"
    ],
    [
     null,
     "tri-clamp-bearing-cap",
     "bearing-cap-2in-b3",
     1,
     "−X branch: two 623 seats, Ø3 bore 75.1 long"
    ],
    [
     null,
     "tri-clamp-displacer",
     "displacer-shell-2in-60",
     1,
     "Ø46 × 60, 0.75 radial gap, 12 stroke"
    ],
    [
     null,
     "tri-clamp-displacer",
     "displacer-cap-2in",
     1,
     "closes the shell, holds the rod"
    ],
    [
     null,
     "stirling-crankshafts",
     "crankshaft-3x60",
     1,
     "displacer rod (Ø3 × 60), through the insert's guide"
    ],
    [
     null,
     "stirling-crankshafts",
     "crankshaft-3x44",
     1,
     "diaphragm rod (Ø3 × 44)"
    ],
    [
     null,
     "rod-clevises",
     "rod-clevis-3mm",
     2,
     "displacer rod, diaphragm rod"
    ],
    [
     null,
     "connecting-rods-623",
     "conrod-30",
     2,
     "diaphragm (in its clevis gap) and displacer (beside its clevis)"
    ],
    [
     null,
     "ball-bearings-metric",
     "bearing-623",
     6,
     "con-rod eyes (4), bearing cap (2)"
    ],
    [
     null,
     "tri-clamp-cross-crank-webs",
     "inner-crank-web-hub-r6",
     1,
     "on the shaft end"
    ],
    [
     null,
     "tri-clamp-cross-crank-webs",
     "inner-crank-web-link-r6",
     1,
     "on the diaphragm pin; carries the displacer pin"
    ],
    [
     null,
     "dowel-pins-metric",
     "dowel-3x12",
     3,
     "diaphragm crank pin, displacer crank pin, diaphragm clevis pin"
    ],
    [
     null,
     "dowel-pins-metric",
     "dowel-3x20",
     1,
     "displacer clevis pin, con-rod beside the clevis"
    ],
    [
     null,
     "shaft-spacers",
     "spacer-3mm-t2",
     1,
     "on the displacer clevis pin between clevis and con-rod"
    ],
    [
     null,
     "shaft-spacers",
     "spacer-3mm-t1",
     2,
     "hub web to inner 623; outer 623 to flywheel"
    ],
    [
     null,
     "metric-shafts",
     "shaft-3x100",
     1,
     "crankshaft"
    ],
    [
     null,
     "nut-pocket-flywheels",
     "flywheel-100-m8-b3",
     1,
     "outside the bearing cap, hub toward the cap"
    ],
    [
     null,
     "hex-nut-weights",
     "nut-m8",
     12,
     "one in each rim pocket"
    ],
    [
     null,
     "tri-clamp-diaphragm-head",
     "diaphragm-head-2in",
     1,
     "on the top of the run: the power diaphragm, rod inward"
    ],
    [
     null,
     "tri-clamp-diaphragm-membrane",
     "membrane-2in",
     1,
     "clamped in place of the gasket"
    ],
    [
     null,
     "tri-clamp-diaphragm-disc",
     "diaphragm-disc-2in",
     1,
     "gas side of the membrane, boss inward, carries the rod"
    ],
    [
     null,
     "tri-clamp-diaphragm-disc",
     "diaphragm-backing-2in",
     1,
     "head side of the membrane"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m2x8",
     3,
     "heads on the head side, through backing disc, membrane and centre disc"
    ],
    [
     null,
     "hex-nuts-metric",
     "nut-m2",
     3,
     "on the centre disc"
    ],
    [
     null,
     "set-screws-metric",
     "set-m3x4",
     5,
     "grubs: displacer cap, diaphragm disc, two clevises, flywheel"
    ],
    [
     null,
     "set-screws-metric",
     "set-m3x3",
     1,
     "hub web on the shaft"
    ],
    [
     null,
     "spool-hanger-collars",
     "hanger-2in-tab",
     1,
     "on the cross's lower run, bar to the wall"
    ],
    [
     null,
     "spool-hanger-collars",
     "hanger-2in-plain",
     1,
     "closes the hanger"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m4x20",
     2,
     "hanger ears"
    ],
    [
     null,
     "socket-head-cap-screws-metric",
     "shcs-m5x25",
     2,
     "hanger bar through the wall"
    ]
   ]
  }
 },
 "sheet_text": "Build list: Tri-clamp cross diaphragm gamma, 2 in — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/list-tri-clamp-cross-diaphragm-gamma/  (CC BY 4.0)\nBasis: Every part is a free STEP/STL on this site or a standard part with its own page; quantities are the full count, every screw, nut, pin, gasket and clamp.\nCatalog version: 2026-10-20\n\nSizes: see table below\n- A fast gamma in 2 in tri-clamp: a hot cap and short spool over a torch, a cross as the sealed crankcase with the crank inside it, a diaphragm on top and a thin crankshaft out through a long bore to the flywheel.\n- Numbers: Diaphragm 2 in at 12 mm: 11.3 mL swept · displacer Ø46 × 60 at 12 mm: 19.9 mL swept · dead volume 68.1 mL · swept / dead 0.166\n\nsubsystem  object  parts  qty  note\nNone  tri-clamp-cross-engine-frame  cross-engine-frame-2in  1  base, wall, gussets\nNone  tri-clamp-torch-stand  torch-stand-40  1  on the base under the hot cap, post toward the front\nNone  socket-head-cap-screws-metric  shcs-m4x10  2  torch stand to the base\nNone  set-screws-metric  set-m4x10  3  centre the torch head in the stand ring\nNone  tri-clamp-end-cap  tc-cap-2in-flat  2  hot cap (face up, over the flame) and the +X branch\nNone  tri-clamp-hot-gasket  hot-gasket-2in  1  hot joint\nNone  tri-clamp-heat-shield  heat-shield-2in  1  on the hot clamp\nNone  tri-clamp-spool  tc-spool-2in-3in  1  hot cylinder with the cap: displacer inside\nNone  tri-clamp-jacket-shell  jacket-half-2in-56  2  band round the hot spool; the fill is the builder's choice\nNone  tri-clamp-jacket-shell  jacket-port-cap  2  one per jacket half\nNone  socket-head-cap-screws-metric  shcs-m4x30  4  jacket ears\nNone  hex-nuts-metric  nut-m4  6  jacket ears (4), hanger ears (2)\nNone  sanitary-clamp-crosses  cross-2in  1  the crankcase: run vertical, branches along the crankshaft\nNone  tri-clamp-gasket  tc-gasket-2in  3  spool–cross, end cap, bearing cap\nNone  tri-clamp-clamps  clamp-half-2in  10  five joints, two halves each\nNone  socket-head-cap-screws-metric  shcs-m5x30  10  clamp bolts\nNone  hex-nuts-metric  nut-m5  12  clamp nuts (10), hanger bar (2)\nNone  tri-clamp-cross-crankcase-insert  crankcase-insert-2in  1  fills the run; Ø3 displacer-rod guide; crank chamber\nNone  tri-clamp-cross-branch-plug  branch-plug-2in-blind  1  end-cap branch\nNone  tri-clamp-cross-branch-plug  branch-plug-2in-bore16  1  bearing-cap branch\nNone  tri-clamp-bearing-cap  bearing-cap-2in-b3  1  −X branch: two 623 seats, Ø3 bore 75.1 long\nNone  tri-clamp-displacer  displacer-shell-2in-60  1  Ø46 × 60, 0.75 radial gap, 12 stroke\nNone  tri-clamp-displacer  displacer-cap-2in  1  closes the shell, holds the rod\nNone  stirling-crankshafts  crankshaft-3x60  1  displacer rod (Ø3 × 60), through the insert's guide\nNone  stirling-crankshafts  crankshaft-3x44  1  diaphragm rod (Ø3 × 44)\nNone  rod-clevises  rod-clevis-3mm  2  displacer rod, diaphragm rod\nNone  connecting-rods-623  conrod-30  2  diaphragm (in its clevis gap) and displacer (beside its clevis)\nNone  ball-bearings-metric  bearing-623  6  con-rod eyes (4), bearing cap (2)\nNone  tri-clamp-cross-crank-webs  inner-crank-web-hub-r6  1  on the shaft end\nNone  tri-clamp-cross-crank-webs  inner-crank-web-link-r6  1  on the diaphragm pin; carries the displacer pin\nNone  dowel-pins-metric  dowel-3x12  3  diaphragm crank pin, displacer crank pin, diaphragm clevis pin\nNone  dowel-pins-metric  dowel-3x20  1  displacer clevis pin, con-rod beside the clevis\nNone  shaft-spacers  spacer-3mm-t2  1  on the displacer clevis pin between clevis and con-rod\nNone  shaft-spacers  spacer-3mm-t1  2  hub web to inner 623; outer 623 to flywheel\nNone  metric-shafts  shaft-3x100  1  crankshaft\nNone  nut-pocket-flywheels  flywheel-100-m8-b3  1  outside the bearing cap, hub toward the cap\nNone  hex-nut-weights  nut-m8  12  one in each rim pocket\nNone  tri-clamp-diaphragm-head  diaphragm-head-2in  1  on the top of the run: the power diaphragm, rod inward\nNone  tri-clamp-diaphragm-membrane  membrane-2in  1  clamped in place of the gasket\nNone  tri-clamp-diaphragm-disc  diaphragm-disc-2in  1  gas side of the membrane, boss inward, carries the rod\nNone  tri-clamp-diaphragm-disc  diaphragm-backing-2in  1  head side of the membrane\nNone  socket-head-cap-screws-metric  shcs-m2x8  3  heads on the head side, through backing disc, membrane and centre disc\nNone  hex-nuts-metric  nut-m2  3  on the centre disc\nNone  set-screws-metric  set-m3x4  5  grubs: displacer cap, diaphragm disc, two clevises, flywheel\nNone  set-screws-metric  set-m3x3  1  hub web on the shaft\nNone  spool-hanger-collars  hanger-2in-tab  1  on the cross's lower run, bar to the wall\nNone  spool-hanger-collars  hanger-2in-plain  1  closes the hanger\nNone  socket-head-cap-screws-metric  shcs-m4x20  2  hanger ears\nNone  socket-head-cap-screws-metric  shcs-m5x25  2  hanger bar through the wall\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-tri-clamp-cross-diaphragm-gamma\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": [
  "tri-clamp-bearing-cap",
  "tri-clamp-cross-crank-webs",
  "tri-clamp-cross-crankcase-insert",
  "tri-clamp-cross-branch-plug",
  "tri-clamp-cross-engine-frame",
  "sanitary-clamp-crosses",
  "tri-clamp-diaphragm-head",
  "tri-clamp-jacket-shell",
  "tri-clamp-torch-stand",
  "list-tri-clamp-tee-diaphragm-gamma"
 ],
 "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 for the tri-clamp cross diaphragm gamma?",
   "a": "49 parts, every one a free STEP/STL on this site; see the table and the build order on this page."
  },
  {
   "q": "Why is the diaphragm on top and not on a side branch?",
   "a": "The cross's two branches share one axis. With the shaft along it, both rods have to run across it, so they come in from the top and bottom of the run."
  },
  {
   "q": "Which way does it turn, and where does the 90° come from?",
   "a": "The displacer pin sits a quarter turn on from the diaphragm pin on the link web. Turning clockwise seen from the flywheel side, the displacer leads the diaphragm by 90° (the first harmonics of the two strokes are 90.0° apart with the 30 mm con-rods)."
  },
  {
   "q": "Where can the gas leak out?",
   "a": "Only along the crankshaft, through the 75.1 mm long Ø3 bore in the bearing cap; every other joint is a clamped gasket or the clamped membrane."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/list-tri-clamp-cross-diaphragm-gamma/index.md"
}