Flexure ring for the displacer stack: Ø76, Ø96 and Ø116 with Ø60, Ø80 and Ø100 seats — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/tri-clamp-flexure-ring/  (CC BY 4.0)
Basis: Ring Ø = flexure OD + 16, 4 mm thick, flexure-OD × 1 seat, 3 × Ø3.4 on the 0.88 × OD circle (same as the flexure head)
Catalog version: 2026-10-20

Sizes: see table below
- The ring that carries the displacer's flexure stack (stack B) on three M3 standoffs above the flexure head.
- Ø76 / Ø96 / Ø116 × 4 mm for Ø60 / Ø80 / Ø100 leaves, with a seat the flexure OD × 1 mm deep, a centre window hub + 6 (Ø19.2 / Ø23.6 / Ø28), and three Ø3.4 holes on the same circle as the head (Ø52.8 / Ø70.4 / Ø88).

flexure_od_mm  ring_od_mm  thickness_mm  seat_mm  window_mm  hole_circle_mm
60  76  4  Ø60 × 1  19.2  52.8
80  96  4  Ø80 × 1  23.6  70.4
100  116  4  Ø100 × 1  28.0  88.0

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- NASA NTRS: Free-piston Stirling convertor flexure bearing development and life testing — pdf — US Government work — https://ntrs.nasa.gov/citations/20050182933
- Long Earth Society: Tri-clamp Stirling engine builds — web, video — LES site — https://longearthsociety.com/engineering/
- Wikipedia: Free-piston engine — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Free-piston_engine

Free files (CC BY 4.0, Xem Studio; STEP + STL, 3 parts): https://xemstudio.com/files/hardware/tri-clamp-flexure-ring/index.json
API: https://xemstudio.com/api/geometry?object=tri-clamp-flexure-ring