Spool hanger collars: clamp a tri-clamp spool to 2020 extrusion over the flame (1.5, 2, 3 in) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/spool-hanger-collars/  (CC BY 4.0)
Basis: 16 ga tube OD (38.1 / 50.8 / 76.2) from the tri-clamp spool entry; 2020 slot pitch for the mounting tab
Catalog version: 2026-10-20

Sizes: see table below
- 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.

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

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 6 parts): https://xemstudio.com/files/hardware/spool-hanger-collars/index.json
API: https://xemstudio.com/api/geometry?object=spool-hanger-collars