LTD Stirling displacer Ø96 × 8 and Ø146 × 8 — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/ltd-displacer/  (CC BY 4.0)
Basis: Senft LTD rule: displacer diameter ≫ stroke; diameter = chamber bore − 4 (2 mm radial gap, designed)
Catalog version: 2026-10-20

Sizes: see table below
- The wide, thin displacer of the LTD engine: a solid disc Ø96 × 8 for the Ø100 chamber or Ø146 × 8 for the Ø150, with a Ø2 hole at x −5 (under the top plate's rod guide) for the 2 mm rod.
- The 2 mm radial gap to the chamber wall is designed: air passes round the edge as the displacer moves.
- In the 20 mm chamber it moves 10 mm; at Ø96 that sweeps about 72 mL.

file  diameter  thickness  chamber  radial gap  rod hole
ltd-100-displacer  96  8  100  2  2
ltd-150-displacer  146  8  150  2  2

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-displacer/index.json
API: https://xemstudio.com/api/geometry?object=ltd-displacer