Xem Studiomeasured geometryTri-clamp rolling-diaphragm beta, 2 in
A torch-heated beta in two pieces of pressure vessel: a 2 in × 150 cup with the displacer, and the rolling-diaphragm power head straight on top of it, the displacer rod running up through the power piston.
Numbers (with the optional finned cooler; cold end taken at 320 K): power swept 20.0 mL, displacer swept 33.2 mL, dead volume 38 mL (swept/dead 0.52); Schmidt work at 650 / 320 K and 1 bar mean 0.47 J per turn (1.57 pressure ratio, ±23 kPa); shaft power about 0.6–2.3 W at 300–600 rpm (0.25–0.5 of Schmidt).
Exact dimensions. Every part is drawn at true size with no printing tolerance; each part's page lists its mating features and the fit each joint needs, so open those by your process's clearance before making the parts.
46 parts, every one a file here · all STL URLs · Markdown · tick lines as you go (saved in this browser)
| subsystem | object | parts | qty | note | |
|---|---|---|---|---|---|
| None | Frame for the rolling-diaphragm tri-clam | rd-frame-2in STEP · STL | 1 | base, wall, gussets | |
| None | Torch stand for a horizontal tri-clamp h | torch-stand-40 STEP · STL | 1 | on the base, post toward +Y; the heat source is a torch flame 40 mm under the cup | |
| None | Socket head cap screws | shcs-m4x10 STEP · STL | 2 | torch stand to the base | |
| None | Set screws (grub screws) | set-m4x10 STEP · STL | 3 | centre the torch head in the stand ring | |
| None | Tri-clamp cups | cup-2in-150 STEP · STL | 1 | the hot end and displacer cylinder in one piece: no joint near the flame | |
| None | Spool hanger collars | hanger-2in-tab STEP · STL | 1 | on the cup under the top clamp; bar to the wall | |
| None | Spool hanger collars | hanger-2in-plain STEP · STL | 1 | closes the hanger | |
| None | Socket head cap screws | shcs-m5x25 STEP · STL | 2 | hanger bar through the wall | |
| None | Socket head cap screws | shcs-m4x20 STEP · STL | 2 | hanger ears | |
| None | Hex nuts | nut-m4 STEP · STL | 2 | hanger ears | |
| None | Tri-clamp finned cooler | cooler-half-2in-56 STEP · STL | 2 | optional: clamp-on fin halves on the cup under the hanger (the cold end of the displacer cylinder); without them the engine runs with less power, or cool that part of the cup any way you like | |
| None | Socket head cap screws | shcs-m4x30 STEP · STL | 4 | optional: cooler ears (only with the cooler) | |
| None | Hex nuts | nut-m4 STEP · STL | 4 | optional: cooler ears (only with the cooler) | |
| None | Top-hat rolling diaphragm | rd-diaphragm-1.50-h1.50 STEP · STL | 1 | 1.50 in bore, 1.50 in high, flat flange: clamped in the joint in place of a gasket | |
| None | Tri-clamp rolling-diaphragm power head | rd-power-head-2in STEP · STL | 1 | standard 2 in clamp face, Ø38.10 cylinder, bushing seat, crank tower | |
| None | Tri-clamp rolling-diaphragm power head | rd-seat-ring-2in STEP · STL | 1 | in the head's face recess, behind the diaphragm flange | |
| None | Tri-clamp clamp | clamp-half-2in STEP · STL | 2 | 1 joint, two halves each | |
| None | Socket head cap screws | shcs-m5x30 STEP · STL | 2 | clamp bolts | |
| None | Hex nuts | nut-m5 STEP · STL | 4 | clamp nuts (2), hanger bar (2) | |
| None | Plain sleeve bushings Ø3 to Ø10 ID | bushing-5x8x12 STEP · STL | 2 | back to back in the head's Ø8 seat: guide the tube rod | |
| None | Rolling-diaphragm piston and head retain | rd-piston-2in STEP · STL | 1 | Ø33.27, never touches the bore | |
| None | Rolling-diaphragm piston and head retain | rd-retainer-26-gland3 STEP · STL | 1 | clamps the diaphragm head on the crown | |
| None | Button head socket screws | button-m3x8 STEP · STL | 3 | retainer screws into the crown | |
| None | Tube piston rods Ø5 × Ø3.4 | tube-rod-5x3.4x80 STEP · STL | 1 | piston to yoke, through the bushings | |
| None | Rod-end yokes with a side stub pin | rd-yoke-tube5 STEP · STL | 1 | on the tube rod's end | |
| None | Set screws (grub screws) | set-m3x3 STEP · STL | 1 | tube yoke grub | |
| None | Connecting rods 30 to 80 mm centres with | conrod-80 STEP · STL | 1 | power | |
| None | Counterweighted crank discs | cw-crank-disc-stroke20 STEP · STL | 1 | 20 mm stroke, overhung on the shaft end | |
| None | Crankshafts Ø3 | crankshaft-5x80-dflat STEP · STL | 1 | disc face to flywheel hub | |
| None | Shaft spacers for Ø3 | spacer-5mm-t5 STEP · STL | 1 | disc hub to the front bearing | |
| None | Shaft spacers for Ø3 | spacer-5mm-t1 STEP · STL | 1 | ||
| None | Ball bearings | bearing-625 STEP · STL | 2 | in the tower | |
| None | Set-screw shaft collars Ø3 to Ø12 | collar-5mm STEP · STL | 1 | behind the tower | |
| None | Flywheels Ø100–Ø200 with hex-nut rim poc | flywheel-150-m10-b5 STEP · STL | 1 | on the shaft's far end | |
| None | Hex nuts M8 | nut-m10 STEP · STL | 18 | one in each rim pocket | |
| None | Tri-clamp displacer | displacer-shell-2in-120 STEP · STL | 1 | Ø46 × 120, 0.75 radial gap, 20 stroke | |
| None | Tri-clamp displacer | displacer-cap-2in STEP · STL | 1 | closes the shell, holds the rod | |
| None | Displacer rods Ø2 × 60 | rod-3x200 STEP · STL | 1 | displacer rod: up through the piston's gland and tube rod | |
| None | Rod-end yokes with a side stub pin | rd-yoke-rod3 STEP · STL | 1 | on the displacer rod's top, stub pin toward +Y | |
| None | Link webs | rd-link-web-r10-90 STEP · STL | 1 | on crank pin 1, carries pin 2 a quarter turn away | |
| None | Connecting rods 30 to 80 mm centres with | conrod-40 STEP · STL | 1 | displacer | |
| None | Ball bearings | bearing-623 STEP · STL | 4 | one in each con-rod eye | |
| None | Dowel pins | dowel-3x12 STEP · STL | 2 | stub pins in the two yokes | |
| None | Dowel pins | dowel-3x20 STEP · STL | 1 | crank pin 1: disc, power con-rod, link web | |
| None | Dowel pins | dowel-3x16 STEP · STL | 1 | crank pin 2: link web, displacer con-rod | |
| None | Set screws (grub screws) | set-m3x4 STEP · STL | 6 | grubs: displacer cap, rod yoke, piston, crank disc, collar, flywheel |
Assembled engine
A torch-heated 2 in tri-clamp beta Stirling engine with a rolling-diaphragm power piston: a 150 mm cup with the displacer, the power head clamped straight on it with the diaphragm's flange as the joint's seal, the displacer rod running up through the power piston, a two-throw overhung crank and a Ø150 flywheel, hung on a wall frame over a torch stand; about 375 × 150 × 507 mm.
Assembly STEP (2.8 MB) · STL (7.8 MB) · 94 parts
Build order
- Frame on the bench; torch stand on the base, post toward +Y.
- Displacer: shell, cap, Ø3 × 200 rod through the cap (grub). Drop it into the cup.
- Hanger on the cup; hang the cup on the wall. Optional: cooler halves on the cup under the hanger, four M4 × 30 and nuts.
- Piston: diaphragm head on the crown, gland retainer, three M3 × 8 button screws; tube rod in the socket (grub). Thread the displacer rod through the gland and the tube.
- Power head: two bushings in the seat, seat ring in the face recess; tube rod up through the bushings so the piston sits in the bore; diaphragm flange on the cup's face, power head on top, clamp.
- Tube yoke on the tube (grub), rod yoke on the rod (grub), stub pins in both. Crank: bearings, shaft, spacers, disc with pin 1, power con-rod, link web with pin 2, displacer con-rod; collar and flywheel with its nuts.
Agents: each row's object has /api/geometry?object=slug and the MCP tool get_free_files; the STL list above is every part.