LTD Stirling chamber ring, Ø100 and Ø150 × 20 — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/ltd-chamber-ring/  (CC BY 4.0)
Basis: Chamber height 20: an 8 mm displacer at 10 mm stroke (crank-disc-b3-stroke10) with 1 mm at each end; M3 tap drill Ø2.5
Catalog version: 2026-10-20

Sizes: see table below
- The wall of the LTD displacer chamber, between the bottom and top plates. Bore Ø100 or Ø150, 20 tall, 10 mm wall (outside Ø120 / Ø170).
- Six Ø2.5 holes (M3 tap drill) through its height on a Ø112 / Ø162 circle: an M3 × 12 comes in from each plate.
- The displacer runs inside with a 2 mm radial gap by design; nothing moving touches the ring.

file  bore  outside  height  screw circle
ltd-100-chamber-ring-h20  100  120  20  112
ltd-150-chamber-ring-h20  150  170  20  162

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: Stirling engine — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Stirling_engine
- James R. Senft: An Introduction to Low Temperature Differential Stirling Engines — book — Moriya Press [verify license at link] — https://www.stirlingengine.com/
- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 2 parts): https://xemstudio.com/files/hardware/ltd-chamber-ring/index.json
API: https://xemstudio.com/api/geometry?object=ltd-chamber-ring