Flexure rim clamp plate: Ø40 to Ø120 × 3 mm, 3 × M3 — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/flexure-rim-clamp-plate/  (CC BY 4.0)
Basis: Ring = the flexure rim (OD, width 0.12 OD), 3 mm thick, 3 × Ø3.4 on the 0.88 × OD circle
Catalog version: 2026-10-20

Sizes: see table below
- A 3 mm ring the size of the leaf rim with three Ø3.4 holes on the rim-hole circle: it clamps the stack of leaf rims and spacers down to the head.
- Ø40 to Ø120; hole circles Ø35.2 / 52.8 / 70.4 / 88 / 105.6, matching the leaves and the tri-clamp flexure head.

od_mm  width_mm  thickness_mm  holes  hole_circle_mm
40  4.8  3  3 × Ø3.4  35.2
60  7.2  3  3 × Ø3.4  52.8
80  9.6  3  3 × Ø3.4  70.4
100  12  3  3 × Ø3.4  88.0
120  14.4  3  3 × Ø3.4  105.6

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- NASA (NTRS, public domain): Free-piston Stirling convertor flexure bearing development and life testing (2005) — PDF — US Government work, public domain — https://ntrs.nasa.gov/search?q=20050182933
- NASA (NTRS, public domain): Flexure bearing design for free-piston Stirling engines (1986) — PDF — US Government work, public domain — https://ntrs.nasa.gov/search?q=19860020334
- NASA (NTRS, public domain): Advanced Stirling Radioisotope Generator (ASRG) engineering unit (2011) — PDF — US Government work, public domain — https://ntrs.nasa.gov/search?q=20110016393
- Wikipedia: Flexure bearing — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Flexure_bearing
- Sunpower (AMETEK): Free-piston Stirling technology overview — web — Sunpower site [verify license at link] — https://sunpowerinc.com/
- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 5 parts): https://xemstudio.com/files/hardware/flexure-rim-clamp-plate/index.json
API: https://xemstudio.com/api/geometry?object=flexure-rim-clamp-plate