{
 "object": "free-piston-core",
 "license": "CC BY 4.0, Xem Studio",
 "les": "https://longearthsociety.com/engineering/",
 "files": [
  {
   "name": "displacer-30x75",
   "step": "/files/hardware/free-piston-core/displacer-30x75.step",
   "stl": "/files/hardware/free-piston-core/displacer-30x75.stl",
   "note": "displacer \u00d829 (0.5 mm radial gap in a \u00d830 bore) \u00d7 75, hollow 1.2 wall, \u00d85 rod boss"
  },
  {
   "name": "power-piston-30x30",
   "step": "/files/hardware/free-piston-core/power-piston-30x30.step",
   "stl": "/files/hardware/free-piston-core/power-piston-30x30.stl",
   "note": "power piston \u00d829.9 \u00d7 30 (clearance-seal blank: lap to fit), \u00d85 rod"
  },
  {
   "name": "cylinder-liner-30x120",
   "step": "/files/hardware/free-piston-core/cylinder-liner-30x120.step",
   "stl": "/files/hardware/free-piston-core/cylinder-liner-30x120.stl",
   "note": "cylinder liner \u00d830 bore \u00d7 120, 3 wall (print to check layout; real liner is honed tube or a glass/brass tube from the library)"
  },
  {
   "name": "gas-spring-piston-15x15",
   "step": "/files/hardware/free-piston-core/gas-spring-piston-15x15.step",
   "stl": "/files/hardware/free-piston-core/gas-spring-piston-15x15.stl",
   "note": "gas-spring piston \u00d814.9 \u00d7 15 for a \u00d815 bounce-space bore"
  },
  {
   "name": "stop-bumper-30",
   "step": "/files/hardware/free-piston-core/stop-bumper-30.step",
   "stl": "/files/hardware/free-piston-core/stop-bumper-30.stl",
   "note": "end-stop bumper for a \u00d830 bore (TPU), 6 tall"
  },
  {
   "name": "displacer-40x100",
   "step": "/files/hardware/free-piston-core/displacer-40x100.step",
   "stl": "/files/hardware/free-piston-core/displacer-40x100.stl",
   "note": "displacer \u00d839 (0.5 mm radial gap in a \u00d840 bore) \u00d7 100, hollow 1.2 wall, \u00d85 rod boss"
  },
  {
   "name": "power-piston-40x40",
   "step": "/files/hardware/free-piston-core/power-piston-40x40.step",
   "stl": "/files/hardware/free-piston-core/power-piston-40x40.stl",
   "note": "power piston \u00d839.9 \u00d7 40 (clearance-seal blank: lap to fit), \u00d85 rod"
  },
  {
   "name": "cylinder-liner-40x160",
   "step": "/files/hardware/free-piston-core/cylinder-liner-40x160.step",
   "stl": "/files/hardware/free-piston-core/cylinder-liner-40x160.stl",
   "note": "cylinder liner \u00d840 bore \u00d7 160, 3 wall (print to check layout; real liner is honed tube or a glass/brass tube from the library)"
  },
  {
   "name": "gas-spring-piston-20x20",
   "step": "/files/hardware/free-piston-core/gas-spring-piston-20x20.step",
   "stl": "/files/hardware/free-piston-core/gas-spring-piston-20x20.stl",
   "note": "gas-spring piston \u00d819.9 \u00d7 20 for a \u00d820 bounce-space bore"
  },
  {
   "name": "stop-bumper-40",
   "step": "/files/hardware/free-piston-core/stop-bumper-40.step",
   "stl": "/files/hardware/free-piston-core/stop-bumper-40.stl",
   "note": "end-stop bumper for a \u00d840 bore (TPU), 6 tall"
  },
  {
   "name": "displacer-rod-5x150-grooved",
   "step": "/files/hardware/free-piston-core/displacer-rod-5x150-grooved.step",
   "stl": "/files/hardware/free-piston-core/displacer-rod-5x150-grooved.stl",
   "note": "\u00d85 \u00d7 150 displacer rod with E-clip grooves"
  }
 ]
}