# Tri-clamp displacers and engine heads: 1.5, 2 and 3 in spools

> What size displacer fits a 2 inch tri-clamp spool and what caps do I need to make it a Stirling engine?

- Category: Stirling engines › Tri-clamp engine parts
- Kind: Hardware
- Basis: 16 ga ASME BPE tube bores (1.5 in = 34.8 mm, 2 in = 47.5, 3 in = 72.9) from the tri-clamp spool entry; displacer radial gap 0.6–1.0 mm for low-ΔT air engines (Senft); ISO 2852 cap face from the tri-clamp end cap entry
- Page: https://xemstudio.com/objects/tri-clamp-displacers-and-heads/ · JSON: https://xemstudio.com/api/geometry?object=tri-clamp-displacers-and-heads · Plain text: https://xemstudio.com/objects/tri-clamp-displacers-and-heads/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses

## Notes

- Displacer diameter = bore − 2 × gap: 1.5 in → Ø33.6, 2 in → Ø46.0, 3 in → Ø70.9. Length 1.5–2.5 × bore (the longer, the bigger the temperature difference it can hold across itself); stroke 0.3–0.4 × length. A 2 in × 6 in spool takes the Ø46 × 90 displacer with a 30 mm stroke.
- Shell displacers: 1 mm wall, closed hot end, internal rings every 25 mm, printed open end up (no supports); the cap presses in and carries the Ø3 rod on an M3 grub. Mass matters less than you think at 2–5 Hz; stiffness and straightness matter more. PETG for a cold end under 80 °C; the hot end of the displacer sees the hot plate only by radiation: PETG survives a tea-light engine, use a foam-and-foil or a thin stainless cup over the nose for a burner engine.
- Regenerative (annular-gap) displacer: 1.5 mm gap and 12 slots packed with #100 stainless mesh turn the gap into the regenerator (Senft's LTD trick); use it in a single spool with no separate regenerator section. Foam templates: cut closed-cell foam (EVA, pool noodle) to Ø and length with the cross lines for centring the rod.
- Heads (ISO 2852 caps with features on the back, so a stock clamp and gasket seal them): displacer head (3/32 in brass guide tube press-fit on centre + 4 mm barb), power head (10 mL syringe barrel socket, Ø15.9, as the power cylinder + M5 port), instrument head (DS18B20, K-type and a barb), crank head (Ø3 rod gland with an O-ring groove and two 623 towers 24 mm up for a crankshaft right on the cap). Heads print flat, face down, at 0.15 mm layers; sand the sealing land.
- Engine recipes: Gamma, 2 in: hot ferrule + 6 in spool + displacer head on top, Ø46 × 90 shell displacer, power head with a 10 mL syringe on a side tee or the crank head; flywheel Ø100 on the crank kit. Beta: one spool, regenerative displacer, crank head on the cold end. Free-piston: 2 in spool, Ø46 displacer on the spiral flexures, power piston from the free-piston core.
- LES: this is the shelf the LES engines are literally built from; every head here replaces a flat cap that used to be drilled by hand.

## Sizes

| spool | bore_mm | displacer_od_mm | length_mm | radial_gap_mm | type |
|---|---|---|---|---|---|
| 1.5 | 34.800000000000004 | 33.6 | 50 | 0.6 | shell / foam |
| 1.5 | 34.800000000000004 | 33.6 | 75 | 0.6 | shell / foam |
| 1.5 | 34.800000000000004 | 33.6 | 100 | 0.6 | shell / foam |
| 2 | 47.5 | 46.0 | 60 | 0.75 | shell / foam |
| 2 | 47.5 | 46.0 | 90 | 0.75 | shell / foam |
| 2 | 47.5 | 46.0 | 120 | 0.75 | shell / foam |
| 3 | 72.9 | 70.9 | 80 | 1.0 | shell / foam |
| 3 | 72.9 | 70.9 | 120 | 1.0 | shell / foam |
| 3 | 72.9 | 70.9 | 160 | 1.0 | shell / foam |

## Where the files are

- Long Earth Society: [Tri-clamp Stirling engine builds](https://longearthsociety.com/engineering/) — web, video — LES site
- James R. Senft: [An Introduction to Low Temperature Differential Stirling Engines (displacer and gap design)](https://www.stirlingengine.com/) — book — Moriya Press (verify at link)
- Wikipedia: [Stirling engine](https://en.wikipedia.org/wiki/Stirling_engine) — web — CC BY-SA 4.0 (text)

## Free STEP/STL (46 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/index.json

- displacer-shell-1.5in-50: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-1.5in-50.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-1.5in-50.stl) — 1.5 in shell displacer Ø33.6 × 50 for the Ø34.8 bore (0.6 mm radial gap), 1 mm wall, ribbed; print open end up, 0.8 mm nozzle-friendly
- displacer-cap-1.5in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-1.5in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-1.5in.stl) — 1.5 in displacer end cap with Ø3 rod boss and M3 grub (print one per displacer)
- displacer-foam-template-1.5in-50: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-1.5in-50.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-1.5in-50.stl) — 1.5 in foam displacer cutting template Ø33.6 × 50 with centre and cross lines
- displacer-shell-1.5in-75: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-1.5in-75.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-1.5in-75.stl) — 1.5 in shell displacer Ø33.6 × 75 for the Ø34.8 bore (0.6 mm radial gap), 1 mm wall, ribbed; print open end up, 0.8 mm nozzle-friendly
- displacer-cap-1.5in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-1.5in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-1.5in.stl) — 1.5 in displacer end cap with Ø3 rod boss and M3 grub (print one per displacer)
- displacer-foam-template-1.5in-75: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-1.5in-75.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-1.5in-75.stl) — 1.5 in foam displacer cutting template Ø33.6 × 75 with centre and cross lines
- displacer-shell-1.5in-100: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-1.5in-100.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-1.5in-100.stl) — 1.5 in shell displacer Ø33.6 × 100 for the Ø34.8 bore (0.6 mm radial gap), 1 mm wall, ribbed; print open end up, 0.8 mm nozzle-friendly
- displacer-cap-1.5in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-1.5in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-1.5in.stl) — 1.5 in displacer end cap with Ø3 rod boss and M3 grub (print one per displacer)
- displacer-foam-template-1.5in-100: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-1.5in-100.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-1.5in-100.stl) — 1.5 in foam displacer cutting template Ø33.6 × 100 with centre and cross lines
- displacer-regenerative-1.5in-75: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-regenerative-1.5in-75.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-regenerative-1.5in-75.stl) — 1.5 in annular-gap regenerative displacer Ø31.8 × 75: 12 radial slots to pack with #100 mesh, 1.5 mm gap
- displacer-regenerative-cap-1.5in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-regenerative-cap-1.5in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-regenerative-cap-1.5in.stl) — cap for the 1.5 in regenerative displacer
- head-displacer-1.5in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-displacer-1.5in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-displacer-1.5in.stl) — 1.5 in ISO 2852 cap: centre press-fit bore for 3/32 in brass guide tube, 4 mm transfer-port barb
- head-power-syringe-1.5in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-power-syringe-1.5in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-power-syringe-1.5in.stl) — 1.5 in ISO 2852 cap: socket for a 10 mL syringe barrel (Ø15.9) as the power cylinder, M5 instrument/vent port
- head-instrument-1.5in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-instrument-1.5in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-instrument-1.5in.stl) — 1.5 in ISO 2852 cap: Ø6.15 DS18B20, Ø3.15 K-type, 4.2 barb port, M3 pinch screws
- head-crank-1.5in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-crank-1.5in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-crank-1.5in.stl) — 1.5 in ISO 2852 cap: Ø3 rod gland with 1.5 CS O-ring groove and two 623 bearing towers for a Ø3 crankshaft 24 mm above the cap
- displacer-shell-2in-60: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-2in-60.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-2in-60.stl) — 2 in shell displacer Ø46 × 60 for the Ø47.5 bore (0.75 mm radial gap), 1 mm wall, ribbed; print open end up, 0.8 mm nozzle-friendly
- displacer-cap-2in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-2in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-2in.stl) — 2 in displacer end cap with Ø3 rod boss and M3 grub (print one per displacer)
- displacer-foam-template-2in-60: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-2in-60.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-2in-60.stl) — 2 in foam displacer cutting template Ø46 × 60 with centre and cross lines
- displacer-shell-2in-90: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-2in-90.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-2in-90.stl) — 2 in shell displacer Ø46 × 90 for the Ø47.5 bore (0.75 mm radial gap), 1 mm wall, ribbed; print open end up, 0.8 mm nozzle-friendly
- displacer-cap-2in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-2in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-2in.stl) — 2 in displacer end cap with Ø3 rod boss and M3 grub (print one per displacer)
- displacer-foam-template-2in-90: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-2in-90.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-2in-90.stl) — 2 in foam displacer cutting template Ø46 × 90 with centre and cross lines
- displacer-shell-2in-120: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-2in-120.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-2in-120.stl) — 2 in shell displacer Ø46 × 120 for the Ø47.5 bore (0.75 mm radial gap), 1 mm wall, ribbed; print open end up, 0.8 mm nozzle-friendly
- displacer-cap-2in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-2in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-2in.stl) — 2 in displacer end cap with Ø3 rod boss and M3 grub (print one per displacer)
- displacer-foam-template-2in-120: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-2in-120.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-2in-120.stl) — 2 in foam displacer cutting template Ø46 × 120 with centre and cross lines
- displacer-regenerative-2in-90: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-regenerative-2in-90.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-regenerative-2in-90.stl) — 2 in annular-gap regenerative displacer Ø44.5 × 90: 12 radial slots to pack with #100 mesh, 1.5 mm gap
- displacer-regenerative-cap-2in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-regenerative-cap-2in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-regenerative-cap-2in.stl) — cap for the 2 in regenerative displacer
- head-displacer-2in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-displacer-2in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-displacer-2in.stl) — 2 in ISO 2852 cap: centre press-fit bore for 3/32 in brass guide tube, 4 mm transfer-port barb
- head-power-syringe-2in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-power-syringe-2in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-power-syringe-2in.stl) — 2 in ISO 2852 cap: socket for a 10 mL syringe barrel (Ø15.9) as the power cylinder, M5 instrument/vent port
- head-instrument-2in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-instrument-2in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-instrument-2in.stl) — 2 in ISO 2852 cap: Ø6.15 DS18B20, Ø3.15 K-type, 4.2 barb port, M3 pinch screws
- head-crank-2in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-crank-2in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-crank-2in.stl) — 2 in ISO 2852 cap: Ø3 rod gland with 1.5 CS O-ring groove and two 623 bearing towers for a Ø3 crankshaft 24 mm above the cap
- displacer-shell-3in-80: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-3in-80.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-3in-80.stl) — 3 in shell displacer Ø70.9 × 80 for the Ø72.9 bore (1.0 mm radial gap), 1 mm wall, ribbed; print open end up, 0.8 mm nozzle-friendly
- displacer-cap-3in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-3in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-3in.stl) — 3 in displacer end cap with Ø3 rod boss and M3 grub (print one per displacer)
- displacer-foam-template-3in-80: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-3in-80.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-3in-80.stl) — 3 in foam displacer cutting template Ø70.9 × 80 with centre and cross lines
- displacer-shell-3in-120: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-3in-120.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-3in-120.stl) — 3 in shell displacer Ø70.9 × 120 for the Ø72.9 bore (1.0 mm radial gap), 1 mm wall, ribbed; print open end up, 0.8 mm nozzle-friendly
- displacer-cap-3in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-3in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-3in.stl) — 3 in displacer end cap with Ø3 rod boss and M3 grub (print one per displacer)
- displacer-foam-template-3in-120: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-3in-120.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-3in-120.stl) — 3 in foam displacer cutting template Ø70.9 × 120 with centre and cross lines
- displacer-shell-3in-160: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-3in-160.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-shell-3in-160.stl) — 3 in shell displacer Ø70.9 × 160 for the Ø72.9 bore (1.0 mm radial gap), 1 mm wall, ribbed; print open end up, 0.8 mm nozzle-friendly
- displacer-cap-3in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-3in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-cap-3in.stl) — 3 in displacer end cap with Ø3 rod boss and M3 grub (print one per displacer)
- displacer-foam-template-3in-160: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-3in-160.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-foam-template-3in-160.stl) — 3 in foam displacer cutting template Ø70.9 × 160 with centre and cross lines
- displacer-regenerative-3in-120: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-regenerative-3in-120.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-regenerative-3in-120.stl) — 3 in annular-gap regenerative displacer Ø69.9 × 120: 12 radial slots to pack with #100 mesh, 1.5 mm gap
- displacer-regenerative-cap-3in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-regenerative-cap-3in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/displacer-regenerative-cap-3in.stl) — cap for the 3 in regenerative displacer
- head-displacer-3in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-displacer-3in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-displacer-3in.stl) — 3 in ISO 2852 cap: centre press-fit bore for 3/32 in brass guide tube, 4 mm transfer-port barb
- head-power-syringe-3in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-power-syringe-3in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-power-syringe-3in.stl) — 3 in ISO 2852 cap: socket for a 10 mL syringe barrel (Ø15.9) as the power cylinder, M5 instrument/vent port
- head-instrument-3in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-instrument-3in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-instrument-3in.stl) — 3 in ISO 2852 cap: Ø6.15 DS18B20, Ø3.15 K-type, 4.2 barb port, M3 pinch screws
- head-crank-3in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-crank-3in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/head-crank-3in.stl) — 3 in ISO 2852 cap: Ø3 rod gland with 1.5 CS O-ring groove and two 623 bearing towers for a Ø3 crankshaft 24 mm above the cap
- rod-gland-bushing-3mm: [STEP](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/rod-gland-bushing-3mm.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-displacers-and-heads/rod-gland-bushing-3mm.stl) — stand-alone rod gland bushing Ø3 with O-ring groove, press into a Ø8.1 hole

## Questions

**What diameter displacer for a 2 inch tri-clamp spool?**

Ø46 mm (47.5 mm bore minus a 0.75 mm radial gap), 60–120 mm long; the Ø46 × 90 shell with a 30 mm stroke suits a 6 in spool.

**How much clearance should a Stirling displacer have?**

0.5–1 mm radial for a low-temperature air engine: 0.6 mm in a 1.5 in spool, 0.75 in a 2 in, 1.0 in a 3 in. Wider wastes the temperature difference, tighter rubs when the shell warms.

**How do I seal the displacer rod through a tri-clamp cap?**

Print the crank head: a Ø3.1 bore with a 1.5 mm cross-section O-ring groove 5 mm up; a light smear of silicone grease and the Ø3 rod runs sealed. The displacer head instead uses a 3/32 in brass tube as a guide (no seal needed on the displacer side of a gamma engine).

**Can I use a syringe as the power piston on a tri-clamp engine?**

Yes: the power head has a Ø15.9 socket for a 10 mL syringe barrel; the plunger (tip removed) is the piston. For a 2 in engine that gives about 2 mL of swept volume per 12 mm of stroke, which matches a Ø46 × 90 displacer at 30 mm stroke.

**What is a regenerative displacer?**

A displacer whose wall gap is the regenerator: slots in the shell packed with stainless mesh, 1.5 mm gap; the gas shuttles through the mesh as the displacer moves, so one spool makes a complete engine (Senft's LTD design).

## Fits with

- [Tri-clamp spool (two ferrules on a tube), 1.5 and 2 inch](https://xemstudio.com/objects/tri-clamp-spool/)
- [Tri-clamp end cap and gasket, 1.5 and 2 inch](https://xemstudio.com/objects/tri-clamp-end-cap/)
- [Tri-clamp (Tri-Clover) sanitary ferrule, 1/2 to 4 inch](https://xemstudio.com/objects/tri-clamp-ferrule/)
- [Plastic syringes 1–60 mL as pistons and cylinders](https://xemstudio.com/objects/plastic-syringes/)
- [Hobby brass tube (K&S), 1/16–21/32 in and 1–12 mm, telescoping](https://xemstudio.com/objects/brass-tube-ks/)
- [Crank discs, connecting rods and flywheels for model engines](https://xemstudio.com/objects/crank-conrod-flywheel-kit/)
- [Regenerator and heat materials: stainless mesh counts, steel wool, scrubbers, mica, fiberglass, ceramic, firebrick](https://xemstudio.com/objects/regenerator-and-heat-materials/)
- [Planar spiral flexure bearings (Sunpower / NASA free-piston style): Ø40–120, DXF + STEP](https://xemstudio.com/objects/spiral-flexure-bearings/)
- [Free-piston Stirling core: displacer, power piston, liner, gas spring, stops, clearance-seal and tuning tables](https://xemstudio.com/objects/free-piston-core/)
- [Instrumentation: DS18B20 and K-type probes, hall sensor, encoder disc, dial-indicator stems](https://xemstudio.com/objects/instrument-mounts/)
- [O-rings, common metric sizes (ISO 3601)](https://xemstudio.com/objects/o-rings-metric/)
- [Ball bearings, 683 to 6210 and flanged F6xx (ISO 15)](https://xemstudio.com/objects/ball-bearings-metric/)