# Spool hanger collars: clamp a tri-clamp spool to 2020 extrusion over the flame (1.5, 2, 3 in)

> How do I hold a tri-clamp Stirling engine upright over a flame?

- Category: Stirling engines › Tri-clamp engine parts
- Kind: Hardware
- Basis: 16 ga tube OD (38.1 / 50.8 / 76.2) from the tri-clamp spool entry; 2020 slot pitch for the mounting tab
- Page: https://xemstudio.com/objects/spool-hanger-collars/ · JSON: https://xemstudio.com/api/geometry?object=spool-hanger-collars · Plain text: https://xemstudio.com/objects/spool-hanger-collars/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses

**Exact dimensions.** Every file is drawn at true size with no printing tolerance. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your printer's or process's clearance before making the part.

## Notes

- A split collar bored to the tube OD with a 1 mm split each side, closed with two M4 screws, holds the spool anywhere along its cold half; the bar half takes two M5 screws and T-nuts into a horizontal 2020 crossbar between two uprights, so a vertical beta, free-piston or thermoacoustic engine hangs with its hot end over a tea light or burner and the base stays cool.
- Clamp on the cold side only; two collars on two uprights for a long spool. For a horizontal gamma use the base plate instead.
- LES: how the vertical engines stand.

## Mating features (exact size; open press / slide / run / socket by your process clearance, leave designed and clamp as drawn)

| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| collar bore | tube OD (38.1 / 50.8 / 76.2) | tri-clamp tube; the split closes on it | clamp | all |

## Sizes

| size | tube_od_mm | collar_id_mm | width_mm | closure | mount |
|---|---|---|---|---|---|
| 1.5 | 38.1 | 38.1 | 16 | 2 × M4 × 30 + nuts | 2 × M5 at 66.1 mm to a 2020 crossbar |
| 2 | 50.8 | 50.8 | 16 | 2 × M4 × 30 + nuts | 2 × M5 at 78.8 mm to a 2020 crossbar |
| 3 | 76.2 | 76.2 | 16 | 2 × M4 × 30 + nuts | 2 × M5 at 104.2 mm to a 2020 crossbar |

## Where the files are

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

## Free STEP/STL (6 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/spool-hanger-collars/index.json

- hanger-1.5in-tab: [STEP](https://xemstudio.com/files/hardware/spool-hanger-collars/hanger-1.5in-tab.step) · [STL](https://xemstudio.com/files/hardware/spool-hanger-collars/hanger-1.5in-tab.stl) — 1.5 in spool hanger, half with the mounting bar: clamps the Ø38.1 tube; 2 × M5 at 66.1 mm centres into a horizontal 2020 crossbar's slot
- hanger-1.5in-plain: [STEP](https://xemstudio.com/files/hardware/spool-hanger-collars/hanger-1.5in-plain.step) · [STL](https://xemstudio.com/files/hardware/spool-hanger-collars/hanger-1.5in-plain.stl) — 1.5 in spool hanger, plain half: 2 × M4 × 30 close it on the tube
- hanger-2in-tab: [STEP](https://xemstudio.com/files/hardware/spool-hanger-collars/hanger-2in-tab.step) · [STL](https://xemstudio.com/files/hardware/spool-hanger-collars/hanger-2in-tab.stl) — 2 in spool hanger, half with the mounting bar: clamps the Ø50.8 tube; 2 × M5 at 78.8 mm centres into a horizontal 2020 crossbar's slot
- hanger-2in-plain: [STEP](https://xemstudio.com/files/hardware/spool-hanger-collars/hanger-2in-plain.step) · [STL](https://xemstudio.com/files/hardware/spool-hanger-collars/hanger-2in-plain.stl) — 2 in spool hanger, plain half: 2 × M4 × 30 close it on the tube
- hanger-3in-tab: [STEP](https://xemstudio.com/files/hardware/spool-hanger-collars/hanger-3in-tab.step) · [STL](https://xemstudio.com/files/hardware/spool-hanger-collars/hanger-3in-tab.stl) — 3 in spool hanger, half with the mounting bar: clamps the Ø76.2 tube; 2 × M5 at 104.2 mm centres into a horizontal 2020 crossbar's slot
- hanger-3in-plain: [STEP](https://xemstudio.com/files/hardware/spool-hanger-collars/hanger-3in-plain.step) · [STL](https://xemstudio.com/files/hardware/spool-hanger-collars/hanger-3in-plain.stl) — 3 in spool hanger, plain half: 2 × M4 × 30 close it on the tube

## How it fits

### Goes in or on
- [Tri-clamp spool (two ferrules on a tube), 1.5 and 2 inch](https://xemstudio.com/objects/tri-clamp-spool/): clamps the 16 ga tube
- [Tri-clamp cups: closed-end spools (ferrule on a capped tube), 1.5, 2 and 3 in](https://xemstudio.com/objects/tri-clamp-cups/): same tube OD

### Connects to
- [Aluminium T-slot extrusion: 2020, 2040, 2060, 2080, V-slot, 3030, 3060, 4040, 4080, 1010, 1515](https://xemstudio.com/objects/t-slot-extrusions/): bolts to a 2020 crossbar

### Alternatives
- [Gamma frame: base plates for tri-clamp engines, rocker beam and pivot post](https://xemstudio.com/objects/gamma-base-plate-and-beam/): horizontal engines sit on the base plate

### Also needed
- [T-slot attachments: slide-in and drop-in T-nuts, corner brackets, gussets, end caps, slot covers, feet, hole plates](https://xemstudio.com/objects/t-slot-brackets-and-nuts/): M5 T-nuts, corner brackets
- [Socket head cap screws, M2–M8 (ISO 4762 / DIN 912)](https://xemstudio.com/objects/socket-head-cap-screws-metric/): M4 × 30 and M5 screws

## Questions

**How do I mount a vertical tri-clamp Stirling engine?**

Clamp a spool hanger collar around the cold half of the tube and bolt its bar to a horizontal 2020 crossbar with two M5 screws and T-nuts; the hot end hangs over the flame.

## Fits with

- [Aluminium T-slot extrusion: 2020, 2040, 2060, 2080, V-slot, 3030, 3060, 4040, 4080, 1010, 1515](https://xemstudio.com/objects/t-slot-extrusions/)
- [T-slot attachments: slide-in and drop-in T-nuts, corner brackets, gussets, end caps, slot covers, feet, hole plates](https://xemstudio.com/objects/t-slot-brackets-and-nuts/)
- [Tri-clamp spool (two ferrules on a tube), 1.5 and 2 inch](https://xemstudio.com/objects/tri-clamp-spool/)
- [Tri-clamp cups: closed-end spools (ferrule on a capped tube), 1.5, 2 and 3 in](https://xemstudio.com/objects/tri-clamp-cups/)
- [Gamma frame: base plates for tri-clamp engines, rocker beam and pivot post](https://xemstudio.com/objects/gamma-base-plate-and-beam/)