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LTD crank stand for a 623 bearing, axis 112 above the foot
What are the dimensions of the crank stand on a coffee-cup Stirling engine? · Hardware · basis: 623 bearing (3 × 10 × 4) pocket at the bearing OD; M3 clearance Ø3.4 (ISO 273)
Long Earth Society build part. The warm-hand demonstrator. 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
- 1 in table
Notes
- The bearing stand that holds the LTD engine's Ø3 crankshaft above the top plate: a 40 × 6 upright, 119 tall, with a 28 × 14 arch under it that straddles the plate's bosses, on two 20 × 10 × 3 feet (one 68 mm foot with the arch cut out).
- A Ø10 pocket through the 6 mm upright, 112 mm above the foot's underside, holds a 623 bearing (fit: press). That height is what the con-rod needs to reach a piston inside the 90 mm syringe barrel standing in the top plate.
- Two Ø3.4 holes 54 mm apart in the feet take M3 × 8 screws into the top plate's tapped pads. Two stands carry one crankshaft, with the flywheel between them.
Sizes
| part | height | shaft axis | feet | holes | |
|---|---|---|---|---|---|
| ltd-crank-stand-a112 | 119 | 112 | Ø10 × 6 | 68 × 10 × 3 less the 28 arch | 2 × Ø3.4 at 54 |
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 |
|---|---|---|---|---|
| stand bearing pockets | Ø10 | 623 bearing | press | ltd-crank-stand-* |
| stand foot holes | Ø3.4 | M3 screw clearance (ISO 273) | designed | ltd-crank-stand-* |
| stand arch | 28 × 14 | top-plate bosses (no contact) | designed | ltd-crank-stand-* |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| Wikipedia | Stirling engine | web | CC BY-SA 4.0 (text) |
| James R. Senft | An Introduction to Low Temperature Differential Stirling Engines | book | Moriya Press verify |
| Long Earth Society | Engine builds | web, video | LES site |
Free files
★ Free files 1 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| ltd-crank-stand-a112 | crank stand: upright 40 × 6 × 119, Ø10 pocket through it for a 623 with its axis 112 above the foot, 28 × 14 arch under it, 68 × 10 × 3 foot with 2 × Ø3.4 at 54 mm (two per engine) | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=ltd-crank-stand
How it fits
Goes in or on
LTD Stirling top plate with syringe socket, Ø120…2 × M3 down onto the top plate
Ball bearings, 683 to 6210 and flanged F6xx623 in the Ø10 pocketConnects to
Crankshafts Ø3, Ø5 and Ø8 with full-length D-flatØ3 crankshaft through the 623sAlternatives
Crank stand for a 623 bearing, 40 / 60 / 80 mm40 / 60 / 80 mm standsIn these build lists
LTD coffee-cup engineRuns on a cup of coffee: wide thin displacer, small piston.You might also need
Questions
What bearing goes in the LTD crank stand?
A 623 (3 × 10 × 4) in the Ø10 pocket, 112 mm up.
How many stands does the LTD engine use?
Two, 20 mm apart along the Ø3 × 40 crankshaft, with the flywheel between them and a crank disc outside each.