Slip-on fin sleeve for a 2 in closed hot end (nine Ø76 ring fins) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/tri-clamp-ring-fin-sleeve/  (CC BY 4.0)
Basis: Design values; fin set as the finned hot head on this site so the same burner shroud fits
Catalog version: 2026-10-20

Sizes: see table below
- A separate part: a finned cup that slides over the closed end of a 2 in hot spool and sits on it. Bore Ø50.8 (the tube's OD) and an inside bottom shaped to the closed end, so the heat crosses where they touch. Nine Ø76 × 1.5 ring fins at 5 mm pitch take the flame's heat in the burner shroud.
- Optional: the engine runs without it at a lower hot-wall temperature for the same flame.

feature  value
bore  Ø50.8
depth  45.0
fins  9 × Ø76 × 1.5, 5 pitch

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, 1 parts): https://xemstudio.com/files/hardware/tri-clamp-ring-fin-sleeve/index.json
API: https://xemstudio.com/api/geometry?object=tri-clamp-ring-fin-sleeve