# Build list: Tri-clamp horizontal gamma generator, 2 in, chargeable

> What parts do I need to build a Tri-clamp horizontal gamma generator, 2 in, chargeable?

- Category: Stirling engines › Assembled engines
- Kind: List / guide
- 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.
- Page: https://xemstudio.com/objects/list-tri-clamp-horizontal-gamma/ · JSON: https://xemstudio.com/api/geometry?object=list-tri-clamp-horizontal-gamma · Plain text: https://xemstudio.com/objects/list-tri-clamp-horizontal-gamma/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- The classic desk Stirling generator in tri-clamp, built for power: a horizontal closed hot spool over the burner, a bored and honed power spool beside it, both rods to one ball-bearing crank on a pair of posts with a Ø200 flywheel, and a gimbal-motor generator belted off the crank.
- Numbers: Displacer Ø40 × 30 (37.7 mL) · piston Ø48 × 36 (65.1 mL) · 90° · dead 84.5 mL (swept/dead 0.77) · hot wall 500 °C, water-cooled · model shaft power: air 1 atm 2–4 W at 600 rpm; charged 5 bar gauge: air 5–29 W at 600 rpm, helium 13–61 W at 1200 rpm · 2208 generator 6 : 1 by belt: 0.0–3.6 W at 26–28 V at 1 atm

## Sizes

| subsystem | object | parts | qty | note |
|---|---|---|---|---|
| None | tri-clamp-horizontal-gamma-frame | horizontal-gamma-frame-2in | 1 | base, cradle, pedestals, guide, crank uprights |
| None | tri-clamp-torch-stand | torch-stand-40 | 1 | under the shroud's inlet, post toward −Y |
| None | set-screws-metric | set-m4x10 | 3 | centre the torch head in the stand ring |
| None | socket-head-cap-screws-metric | shcs-m4x10 | 4 | torch stand (2), shroud feet (2) |
| None | tri-clamp-horizontal-burner-shroud | burner-shroud-2in-horizontal | 1 | round the fins |
| None | tri-clamp-closed-hot-spool-bored | hot-spool-2in-152.4-closed-bored-48.00 | 1 | the displacer cylinder: lying along −X |
| None | tri-clamp-ring-fin-sleeve | fin-sleeve-2in-9x76 | 1 | optional heat exchanger: slid over the closed end |
| None | tri-clamp-flow-water-jacket | water-jacket-half-2in-48-flow | 2 | optional heat exchanger: round the cold end over the cooler zone, hose spigots up and down |
| None | socket-head-cap-screws-metric | shcs-m4x25 | 4 | optional: water-jacket ears |
| None | hex-nuts-metric | nut-m4 | 4 | optional: water-jacket ears |
| None | stirling-annular-screen-stack | screen-stack-48x42x40-50mesh | 1 | optional heat exchanger (with the liner): on the liner's neck |
| None | stirling-slotted-regenerator-liner | liner-2in-slotted-48-40 | 1 | optional heat exchanger (internal insert), pressed into the hot spool: without it the displacer runs in the Ø48.00 bore 4 mm clear, a plain annular-gap engine with far less power |
| None | stirling-clearance-seal-displacer | displacer-shell-38.5x98 | 1 | the shell |
| None | stirling-clearance-seal-displacer | displacer-cap-40-land | 1 | pressed into the shell; land in the liner bore |
| None | stirling-precision-rods | rod-6x423.2-m6 | 1 | displacer rod: cap to the displacer yoke |
| None | hex-nuts-metric | nut-m6 | 2 | lock nuts: displacer cold face, under the displacer yoke |
| None | tri-clamp-transfer-cap | transfer-cap-2in-rod6 | 1 | on the hot spool: displacer-rod gland, transfer boss +Y, gauge on top, relief below |
| None | tri-clamp-transfer-cap | transfer-cap-2in-blind | 1 | on the power spool's head end: transfer boss −Y, fill on top, plug below |
| None | sleeve-bushings | bushing-6x10x10 | 3 | displacer-rod gland (2), guide block (1) |
| None | high-pressure-sanitary-clamps | hp-clamp-2in | 4 | rating above the 7 bar gauge relief setting (not drawn here) |
| None | tri-clamp-gasket | tc-gasket-2in | 4 | hot spool–cap, cap–power spool, power–bounce spool, bounce spool–gland cap |
| None | stirling-precision-rods | transfer-tube-12.7x0.89x64 | 1 | transfer tube between the two 1/2 NPT fittings |
| None | npt-thread-envelopes | npt-1-2-male | 2 | 1/2 NPT × 1/2 in tube fittings in the transfer bosses (bodies are the builder's choice) |
| None | tri-clamp-spool-bored-honed | spool-2in-3in-bored-48.00 | 1 | power cylinder |
| None | stirling-clearance-seal-pistons | piston-48-gamma-m8 | 1 | Ø48.00, rod side toward the crank |
| None | stirling-precision-rods | rod-8x304.85-m8 | 1 | piston rod |
| None | hex-nuts-metric | nut-m8 | 2 | lock nuts: piston boss, under the power yoke |
| None | tri-clamp-spool-npt-bosses | spool-2in-6in-3x-npt14 | 1 | bounce space: fill on top, gauge and relief at 30° / 150° |
| None | tri-clamp-rod-gland-cap | gland-cap-2in-2x-8x12x20 | 1 | closes the bounce spool; the piston rod's gland and guide |
| None | sleeve-bushings | bushing-8x12x20 | 2 | in the gland cap |
| None | npt-thread-envelopes | npt-1-4-male | 7 | 1/4 NPT stems: working-space gauge, relief, fill and plug; bounce-space fill, gauge and relief (bodies are the builder's choice) |
| None | stirling-crosshead-yokes | yoke-rod6-m6 | 1 | displacer yoke, stub pin toward +Y |
| None | stirling-crosshead-yokes | yoke-rod8-m8 | 1 | power yoke, stub pin toward −Y |
| None | dowel-pins-metric | dowel-5x20 | 2 | stub wrist pins |
| None | shaft-collars | collar-5mm | 2 | on the wrist pins |
| None | set-screws-metric | set-m3x4 | 2 | wrist-pin collars |
| None | stirling-conrods-626-625 | conrod-626-625-100 | 2 | displacer and power |
| None | ball-bearings-metric | bearing-626 | 2 | big ends |
| None | ball-bearings-metric | bearing-625 | 2 | small ends |
| None | stirling-built-up-crank-webs | crank-web-56x10-r15 | 1 | displacer throw, outer |
| None | stirling-built-up-crank-webs | crank-web-56x11-r15 | 1 | displacer throw, inner |
| None | stirling-built-up-crank-webs | crank-web-56x11-r18 | 1 | power throw, inner |
| None | stirling-built-up-crank-webs | crank-web-56x10-r18 | 1 | power throw, outer |
| None | dowel-pins-metric | dowel-6x30 | 2 | crank pins (r 15 displacer, r 18 power, 90° apart) |
| None | stirling-precision-rods | shaft-8x56.5 | 1 | crank stub, −Y bearing |
| None | stirling-precision-rods | shaft-8x88 | 1 | crank centre shaft |
| None | stirling-precision-rods | shaft-8x46.3 | 1 | crank stub, +Y bearing and flywheel |
| None | ball-bearings-metric | bearing-608 | 2 | crank uprights |
| None | shaft-collars | collar-8mm | 2 | inside the uprights: axial location |
| None | set-screws-metric | set-m4x4 | 2 | 8 mm collars |
| None | nut-pocket-flywheels | flywheel-200-m12-b8 | 1 | outboard of the +Y upright |
| None | hex-nut-weights | nut-m12 | 18 | one in each rim pocket |
| None | set-screws-metric | set-m3x6 | 1 | flywheel hub |
| None | spool-hanger-collars | hanger-2in-tab | 2 | power spool and bounce spool, bar down on the pedestals |
| None | spool-hanger-collars | hanger-2in-plain | 2 | close the hangers |
| None | socket-head-cap-screws-metric | shcs-m4x20 | 4 | hanger ears |
| None | hex-nuts-metric | nut-m4 | 4 | hanger ears |
| None | socket-head-cap-screws-metric | shcs-m5x20 | 4 | hanger bars into the pedestals |
| None | round-belt-generator-drive | crank-pulley-84-b8 | 1 | on the crankshaft's free end |
| None | set-screws-metric | set-m4x6 | 1 | crank-pulley hub |
| None | gimbal-motor-2208-envelope | gimbal-motor-2208-envelope | 1 | the generator: 2208 gimbal outrunner, KV 128, 14.4 Ω (envelope at its published size) |
| None | countersunk-screws-metric | csk-m3x6 | 4 | motor base to the bracket, heads flush |
| None | round-belt-generator-drive | generator-pulley-2208-pd13.33 | 1 | on the motor's rotor top |
| None | socket-head-cap-screws-metric | shcs-m2x6 | 4 | generator pulley to the rotor top |
| None | round-belt-generator-drive | round-belt-5-c90 | 1 | drawn on its pitch line) |

## Where the files are

- Long Earth Society: [Engine builds](https://longearthsociety.com/engineering/) — web, video — LES site

## Build order

1. Frame on the bench; torch stand and shroud on the base.
2. Hot end: screen stack on the liner's neck; press the liner into the hot spool until its feet touch the floor. Fin sleeve over the closed end; jacket halves round the cold end.
3. Displacer: cap into the shell; rod into the cap with its M6 lock nut; slide it into the liner, rod out of the face.
4. Transfer cap (rod version) over the rod, gasket and clamp on the hot spool; bushings in its gland. Hot spool on its cradle.
5. Power side: gasket, blind transfer cap, gasket and clamp to the bored spool with the piston and rod in it; bounce spool, gland cap with its bushings, hangers on the pedestals. Join the two transfer bosses with the 1/2 NPT fittings and the tube.
6. Crank: pins and shafts pressed into the webs (90° apart), con-rods with their bearings on the pins, bearings into the uprights, collars, flywheel with its nuts, crank pulley. Yokes on the rods with their lock nuts, wrist pins, con-rods, collars.
7. Generator: pulley on the motor's rotor top (4 × M2), motor on the bracket (4 × M3 countersunk), belt on both pulleys.
8. Ports: water hoses to the jacket spigots; gauge, relief, fill and plug on the transfer caps; fill, gauge, relief on the bounce spool.

All printed STLs: https://xemstudio.com/objects/list-tri-clamp-horizontal-gamma/stl-list.txt

## Questions

**How much power?**

In the model: 2–4 W at the crank at 600 rpm open to air (0.0–3.6 W at 26–28 V); charged to 5 bar gauge, 5–29 W on air and 13–61 W on helium at 1200 rpm.

**Can it run uncharged?**

Yes: open the bounce-space ports and run it at 1 atm.

**Why are the cylinders side by side?**

That is the classic desk layout, and it keeps the transfer passage short: two caps side by side and 64 mm of 1/2 in tube.

**What are the clamps?**

High-pressure bolted sanitary clamps on every joint, rated above the relief setting.

## Fits with

- [2 in × 152.4 mm closed-end hot spool, bore finished Ø48.00](https://xemstudio.com/objects/tri-clamp-closed-hot-spool-bored/)
- [Slotted heater, regenerator and cooler liner for a 2 in hot spool (Ø48.00 / Ø40.00)](https://xemstudio.com/objects/stirling-slotted-regenerator-liner/)
- [2 in × 3 in spool with the bore finished Ø48.00 (bored and honed power cylinder)](https://xemstudio.com/objects/tri-clamp-spool-bored-honed/)
- [2 in end cap with a 1/2 NPT transfer boss, two 1/4 NPT bosses and a spigot (transfer cap)](https://xemstudio.com/objects/tri-clamp-transfer-cap/)
- [Round-belt generator drive: Ø84 crank pulley, 2208 generator pulley, Ø5 belts](https://xemstudio.com/objects/round-belt-generator-drive/)
- [Build list: Tri-clamp walking-beam gamma generator, 2 in, chargeable](https://xemstudio.com/objects/list-tri-clamp-walking-beam-gamma/)
- [Build list: Tri-clamp charged beta, 2 in](https://xemstudio.com/objects/list-tri-clamp-charged-beta/)