Linear alternator housing for Ø80 and Ø100 flexures (2 in / 3 in) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/linear-alternator-housing/  (CC BY 4.0)
Basis: Rim screw circle of the flexure head (R35.2 for Ø80, R44 for Ø100 flexures); sleeve pocket at Ø60.5; M3 clearance Ø3.4
Catalog version: 2026-10-20

Sizes: see table below
- The stator body: a Ø63.7 barrel 36 tall between a base flange and a top flange (Ø96 for the 2 in, Ø116 for the 3 in), each 4 thick.
- From the top, a Ø60.5 pocket (fit: socket) takes the back-iron sleeve on a 2 mm ledge; a Ø40 passage lets the Ø35 mover through without contact; a 2.5 × 3 slot lets the leads out.
- 3 × Ø3.4 holes on the flexure head's rim circle (R35.2 or R44) bolt it to standoffs above flexure stack A; the coil centre sits 21 mm above its underside.

file  flexure  flanges  rim circle  height  sleeve pocket  mover passage
alt-housing-2in-flex80  Ø80 (2 in)  Ø96 × 4  R35.2  36  60.5  40
alt-housing-3in-flex100  Ø100 (3 in)  Ø116 × 4  R44  36  60.5  40

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- NASA (NTRS, public domain): Linear alternator design for free-piston Stirling convertors (2005) — PDF — US Government work, public domain — https://ntrs.nasa.gov/search?q=20050182934
- NASA (NTRS, public domain): Sunpower/NASA 80 We free-piston Stirling convertor (2002) — PDF — US Government work, public domain — https://ntrs.nasa.gov/search?q=20020047256
- Wikipedia: Linear alternator — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Linear_alternator
- Wikipedia: Free-piston engine — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Free-piston_engine
- 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/linear-alternator-housing/index.json
API: https://xemstudio.com/api/geometry?object=linear-alternator-housing