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Flexure stack spacer ring: Ø40 to Ø120 × 2 mm
What spaces the leaves in a flexure bearing stack? · Hardware · basis: Ring = the flexure rim: OD × (OD − 2 × 0.12 OD), 2 mm thick
Long Earth Society build part. Flexure-suspended displacer on the LES free-piston test bed. The engines
Exact dimensions. Every file is drawn at true size with no printing tolerance. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your printer's or process's clearance before making the part. Mating features
- sizes
- 5 in table
Notes
- A plain ring the size of a flexure leaf's rim, 2 mm thick, that sits between leaf rims so the arms can flex without touching.
- Ø40 × 4.8 wide, Ø60 × 7.2, Ø80 × 9.6, Ø100 × 12, Ø120 × 14.4; all 2.0 mm thick, with no rim holes.
Sizes
| od_mm | id_mm | width_mm | thickness_mm |
|---|---|---|---|
| 40 | 30.4 | 4.8 | 2 |
| 60 | 45.6 | 7.2 | 2 |
| 80 | 60.8 | 9.6 | 2 |
| 100 | 76 | 12 | 2 |
| 120 | 91.2 | 14.4 | 2 |
Mating features
Drawn at the exact size. Open press, slide, run and socket features by your process's clearance; leave designed gaps and clamp fits as drawn.
| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| spacer rim holes | Ø3.4 × 3 on R = 0.44·OD (R35.2 on Ø80) | M3 stack screws (clearance) | designed | spacer-* |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| NASA (NTRS, public domain) | Free-piston Stirling convertor flexure bearing development and life testing (2005) | US Government work, public domain | |
| NASA (NTRS, public domain) | Flexure bearing design for free-piston Stirling engines (1986) | US Government work, public domain | |
| NASA (NTRS, public domain) | Advanced Stirling Radioisotope Generator (ASRG) engineering unit (2011) | US Government work, public domain | |
| Wikipedia | Flexure bearing | web | CC BY-SA 4.0 (text) |
| Sunpower (AMETEK) | Free-piston Stirling technology overview | web | Sunpower site verify |
| Long Earth Society | Engine builds | web, video | LES site |
Free files
★ Free files 5 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| spacer-40-t2 | stack spacer ring Ø40, 4.8 wide, 2 thick (sets the gap between leaves), 3 × Ø3.4 on R17.6 (the leaves' rim-hole circle) for the stack screws | STEP · STL |
| spacer-60-t2 | stack spacer ring Ø60, 7.2 wide, 2 thick (sets the gap between leaves), 3 × Ø3.4 on R26.4 (the leaves' rim-hole circle) for the stack screws | STEP · STL |
| spacer-80-t2 | stack spacer ring Ø80, 9.6 wide, 2 thick (sets the gap between leaves), 3 × Ø3.4 on R35.2 (the leaves' rim-hole circle) for the stack screws | STEP · STL |
| spacer-100-t2 | stack spacer ring Ø100, 12 wide, 2 thick (sets the gap between leaves), 3 × Ø3.4 on R44 (the leaves' rim-hole circle) for the stack screws | STEP · STL |
| spacer-120-t2 | stack spacer ring Ø120, 14.4 wide, 2 thick (sets the gap between leaves), 3 × Ø3.4 on R52.8 (the leaves' rim-hole circle) for the stack screws | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=flexure-stack-spacer
How it fits
Goes in or on
Planar spiral flexure bearing leavesbetween leaf rims, same ODConnects to
Flexure rim clamp platestack clamped under the plateAlso needed
Flexure hub washermatching gap at the hubsIn these build lists
Free-piston Stirling, 2 in tri-clampNo crank: piston and displacer each hang on a stack of spiral flexures, with a t…Questions
How thick are the flexure stack spacers?
2.0 mm, the width of the leaf rim (9.6 mm on Ø80).
What size spacer goes with an Ø80 flexure?
Spacer-80-t2: Ø80 OD × Ø60.8 ID × 2.0 mm.