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Crank discs Ø30 for a Ø3 crankshaft, 10 to 20 mm stroke

What crank disc fits a 3 mm crankshaft? · Hardware · basis: Ø30 × 6 disc, Ø3 bore, Ø3 pin hole at stroke / 2, M3 grub

Long Earth Society build part. The connectors between rods, cranks and drives on the LES engines. 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
3 in table

Notes

  • A Ø30 × 6 disc with a Ø3 bore for the crank head's Ø3 crankshaft (623 towers) or the can engine's Ø3 shaft.
  • A Ø3 pin hole at 5.0, 7.5 or 10.0 mm from the axis gives 10, 15 or 20 mm stroke.
  • A radial Ø2.5 hole (M3 tap drill) at mid-thickness locks it to the shaft.

Sizes

filestrokepin offsetdiscbore
crank-disc-b3-stroke10105.0Ø30 × 63
crank-disc-b3-stroke15157.5Ø30 × 63
crank-disc-b3-stroke202010.0Ø30 × 63

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.

featureexactmates withfitfiles
crank-disc boreØ3Ø3 crankshaft (M3 grub)slidecrank-disc-b3-*
crank-disc pin holeØ3Ø3 crank pinpresscrank-disc-b3-*
crank-disc grub holeØ2.5M3 tap drilldesignedcrank-disc-b3-*

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

Long Earth SocietyTri-clamp Stirling engine buildsweb, videoLES site

Free files

★ Free files 3 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json

crank-disc-b3-stroke10crank disc Ø30 for a Ø3 crankshaft (the crank head's 623 towers), pin at 5.0 mm (10 mm stroke), M3 grubSTEP · STL
crank-disc-b3-stroke15crank disc Ø30 for a Ø3 crankshaft (the crank head's 623 towers), pin at 7.5 mm (15 mm stroke), M3 grubSTEP · STL
crank-disc-b3-stroke20crank disc Ø30 for a Ø3 crankshaft (the crank head's 623 towers), pin at 10.0 mm (20 mm stroke), M3 grubSTEP · STL

Plain text: sheet.txt · JSON: /api/geometry?object=crank-discs-3mm-bore

Crank discs Ø30 for a Ø3 crankshaft, 10 to 20 mm stroke, isometric render of a generated part
Render of crank-disc-b3-stroke15 from the free STEP; not to scale.

How it fits

Goes in or on

Crankshafts Ø3, Ø5 and Ø8 with full-length D-flatØ3 crankshaft in the boreTri-clamp displaceron the crank head's Ø3 shaft between the 623 towers

Connects to

Connecting rods 30 to 80 mm centres with 623 pockets623 end on the Ø3 pin

Alternatives

Crank discs for a Ø5 shaft, 10 to 30 mm strokesame discs for a Ø5 shaft

In these build lists

Soda-can gammaA 12 oz can as the displacer cylinder over a tea light, a 10 mL syringe barrel a…LTD coffee-cup engineRuns on a cup of coffee: wide thin displacer, small piston.Mug LTD (sits on a coffee mug)Test-tube marble enginecrank and flywheel at the end.

You might also need

Crank and wrist pins Ø3 × 12, 16, 19, 20 and 23, isometric render of a generated part
Crank and wrist pins Ø3 × 12, 16, 19, 20 and 235 sizes★ 5 files

Questions

What crank disc fits a 3 mm shaft?

Crank-disc-b3: Ø30 × 6, Ø3 bore, M3 grub, pin at 5, 7.5 or 10 mm.

How is the stroke set?

Stroke = 2 × pin offset: 10, 15 or 20 mm.