Xem Studiomeasured geometryLibrary › Stirling engines › Drives & mechanisms ·
Flywheels Ø100–Ø200 with hex-nut rim pockets
How is a flywheel with hex nut pockets in the rim laid out? · Hardware · basis: Rim of hex pockets at the nut's across-flats, one flat facing out, depth = nut thickness; pocket count a multiple of 6
Long Earth Society build part. Flywheels you load with hardware-store nuts. 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
- 8 in table
Notes
- A rim of hex pockets, each at the nut's exact across-flats with one flat facing outward and as deep as the nut is thick, on a 1.5 mm floor; a nut sits flush with the face.
- Pocket counts are multiples of six: all, every other one, every third or one half can be filled and the wheel stays balanced, or one half only makes a counterweight opposite the crank pin.
- Rim thickness = nut thickness + 1.5; rim radial width = across-flats + 6. A 4 mm web with six round windows joins the rim to a hub Ø20 (Ø3 and Ø5 bore) or Ø22 (Ø8 bore), 4 mm taller than the rim.
- Each hub has a radial Ø2.5 hole (M3 tap drill) for a grub on the shaft's D-flat. Ø3 hubs exist on the Ø100 and Ø120 wheels only.
Sizes
| OD | nut | pockets | pocket circle R | rim thickness | rim width | hub | bores |
|---|---|---|---|---|---|---|---|
| 100 | M8 | 12 | 40.5 | 8.3 | 19.0 | Ø20 / Ø22 × 12.3 | 3 / 5 / 8 |
| 120 | M10 | 12 | 49.0 | 9.9 | 22.0 | Ø20 / Ø22 × 13.9 | 3 / 5 / 8 |
| 120 | 3/8 in | 12 | 49.9 | 9.8 | 20.3 | Ø20 / Ø22 × 13.8 | 3 / 5 / 8 |
| 150 | M10 | 18 | 64.0 | 9.9 | 22.0 | Ø20 / Ø22 × 13.9 | 5 / 8 |
| 150 | M12 | 12 | 63.0 | 12.3 | 24.0 | Ø20 / Ø22 × 16.3 | 5 / 8 |
| 150 | 1/2 in | 12 | 62.5 | 12.6 | 25.1 | Ø20 / Ø22 × 16.6 | 5 / 8 |
| 200 | M12 | 18 | 88.0 | 12.3 | 24.0 | Ø20 / Ø22 × 16.3 | 5 / 8 |
| 200 | 1/2 in | 18 | 87.5 | 12.6 | 25.1 | Ø20 / Ø22 × 16.6 | 5 / 8 |
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 |
|---|---|---|---|---|
| hub bore | Ø3 / Ø5 / Ø8 | D-flat crankshaft (M3 grub) | slide | flywheel-* |
| rim pockets | nut across-corners | hex nut, one flat outward | press | flywheel-* |
| grub hole | Ø2.5 | M3 tap drill | designed | flywheel-* |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| ISO | ISO 4032 Hexagon regular nuts (style 1) | standard | ISO verify |
| ASME | ASME B18.2.2 Nuts for general applications | standard | ASME verify |
| Long Earth Society | Engine builds | web, video | LES site |
Free files
★ Free files 19 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| flywheel-100-m8-b3 | Ø100 flywheel, 12 pockets for M8 hex nuts at R40.5 (one flat facing out), Ø3 hub with M3 grub, 8.3 thick rim; full set ≈ 67 g of nuts, +1.1 kg·cm² | STEP · STL |
| flywheel-100-m8-b5 | Ø100 flywheel, 12 pockets for M8 hex nuts at R40.5 (one flat facing out), Ø5 hub with M3 grub, 8.3 thick rim; full set ≈ 67 g of nuts, +1.1 kg·cm² | STEP · STL |
| flywheel-100-m8-b8 | Ø100 flywheel, 12 pockets for M8 hex nuts at R40.5 (one flat facing out), Ø8 hub with M3 grub, 8.3 thick rim; full set ≈ 67 g of nuts, +1.1 kg·cm² | STEP · STL |
| flywheel-120-m10-b3 | Ø120 flywheel, 12 pockets for M10 hex nuts at R49.0 (one flat facing out), Ø3 hub with M3 grub, 9.9 thick rim; full set ≈ 124 g of nuts, +3.0 kg·cm² | STEP · STL |
| flywheel-120-m10-b5 | Ø120 flywheel, 12 pockets for M10 hex nuts at R49.0 (one flat facing out), Ø5 hub with M3 grub, 9.9 thick rim; full set ≈ 124 g of nuts, +3.0 kg·cm² | STEP · STL |
| flywheel-120-m10-b8 | Ø120 flywheel, 12 pockets for M10 hex nuts at R49.0 (one flat facing out), Ø8 hub with M3 grub, 9.9 thick rim; full set ≈ 124 g of nuts, +3.0 kg·cm² | STEP · STL |
| flywheel-120-3-8in-b3 | Ø120 flywheel, 12 pockets for 3/8 in hex nuts at R49.9 (one flat facing out), Ø3 hub with M3 grub, 9.8 thick rim; full set ≈ 93 g of nuts, +2.3 kg·cm² | STEP · STL |
| flywheel-120-3-8in-b5 | Ø120 flywheel, 12 pockets for 3/8 in hex nuts at R49.9 (one flat facing out), Ø5 hub with M3 grub, 9.8 thick rim; full set ≈ 93 g of nuts, +2.3 kg·cm² | STEP · STL |
| flywheel-120-3-8in-b8 | Ø120 flywheel, 12 pockets for 3/8 in hex nuts at R49.9 (one flat facing out), Ø8 hub with M3 grub, 9.8 thick rim; full set ≈ 93 g of nuts, +2.3 kg·cm² | STEP · STL |
| flywheel-150-m10-b5 | Ø150 flywheel, 18 pockets for M10 hex nuts at R64.0 (one flat facing out), Ø5 hub with M3 grub, 9.9 thick rim; full set ≈ 186 g of nuts, +7.6 kg·cm² | STEP · STL |
| flywheel-150-m10-b8 | Ø150 flywheel, 18 pockets for M10 hex nuts at R64.0 (one flat facing out), Ø8 hub with M3 grub, 9.9 thick rim; full set ≈ 186 g of nuts, +7.6 kg·cm² | STEP · STL |
| flywheel-150-m12-b5 | Ø150 flywheel, 12 pockets for M12 hex nuts at R63.0 (one flat facing out), Ø5 hub with M3 grub, 12.3 thick rim; full set ≈ 192 g of nuts, +7.6 kg·cm² | STEP · STL |
| flywheel-150-m12-b8 | Ø150 flywheel, 12 pockets for M12 hex nuts at R63.0 (one flat facing out), Ø8 hub with M3 grub, 12.3 thick rim; full set ≈ 192 g of nuts, +7.6 kg·cm² | STEP · STL |
| flywheel-150-1-2in-b5 | Ø150 flywheel, 12 pockets for 1/2 in hex nuts at R62.5 (one flat facing out), Ø5 hub with M3 grub, 12.6 thick rim; full set ≈ 221 g of nuts, +8.6 kg·cm² | STEP · STL |
| flywheel-150-1-2in-b8 | Ø150 flywheel, 12 pockets for 1/2 in hex nuts at R62.5 (one flat facing out), Ø8 hub with M3 grub, 12.6 thick rim; full set ≈ 221 g of nuts, +8.6 kg·cm² | STEP · STL |
| flywheel-200-m12-b5 | Ø200 flywheel, 18 pockets for M12 hex nuts at R88.0 (one flat facing out), Ø5 hub with M3 grub, 12.3 thick rim; full set ≈ 288 g of nuts, +22.3 kg·cm² | STEP · STL |
| flywheel-200-m12-b8 | Ø200 flywheel, 18 pockets for M12 hex nuts at R88.0 (one flat facing out), Ø8 hub with M3 grub, 12.3 thick rim; full set ≈ 288 g of nuts, +22.3 kg·cm² | STEP · STL |
| flywheel-200-1-2in-b5 | Ø200 flywheel, 18 pockets for 1/2 in hex nuts at R87.5 (one flat facing out), Ø5 hub with M3 grub, 12.6 thick rim; full set ≈ 332 g of nuts, +25.4 kg·cm² | STEP · STL |
| flywheel-200-1-2in-b8 | Ø200 flywheel, 18 pockets for 1/2 in hex nuts at R87.5 (one flat facing out), Ø8 hub with M3 grub, 12.6 thick rim; full set ≈ 332 g of nuts, +25.4 kg·cm² | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=nut-pocket-flywheels
How it fits
Goes in or on
Crankshafts Ø3, Ø5 and Ø8 with full-length D-flatØ3 / Ø5 / Ø8 hub, M3 grub on the flat
Crank stands with a 625 pocket, 40 and 60 mm axis…on the Ø5 shaft outside the standConnects to
Hex nuts M8, M10, M12, 3/8 in and 1/2 innut in each hex pocket, one flat outwardAlternatives
Spoked flywheels Ø50 to Ø150 × 10plain spoked wheelAlso needed
Set screws, M3–M8M3 grubIn these build lists
Gamma Stirling, 2 in tri-clampHot spool with a shell displacer, a crank head that carries the crankshaft, the …Soda-can gammaA 12 oz can as the displacer cylinder over a tea light, a 10 mL syringe barrel a…Beta Stirling, rhombic drive, 2 in tri-clampDisplacer and piston in one bore, driven by two counter-rotating gears on a rhom…LTD coffee-cup engineRuns on a cup of coffee: wide thin displacer, small piston.Alpha V-twin, two 10 mL syringesTwo 10 mL syringe barrels in a 90° V on one crank pin: the V is the 90° phase.Ross yoke alpha, two parallel 10 mL syringesTwo 10 mL syringe barrels side by side on a Ross yoke: a = h gives 90° between t…Tri-clamp tee diaphragm gamma, 2 inA tea-light gamma in 2 in tri-clamp: displacer in a 3 in spool, a short-outlet t…Tri-clamp elbow diaphragm alpha, 2 inA torch-heated alpha in 2 in tri-clamp: a square of fittings with a diaphragm he…You might also need
Questions
How many nuts does the Ø150 flywheel hold?
18 M10 nuts on the M10 wheel (R64), or 12 on the M12 and 1/2 in wheels.
Can I fill only some pockets?
Yes: pocket counts are multiples of six, so all, alternate, every third or one half all leave the wheel balanced, and one half only is a counterweight.
Metric or inch nuts?
The Ø120, Ø150 and Ø200 wheels come in 3/8 in and 1/2 in versions as well as M10 and M12.