Xem Studiomeasured geometryTorsion spring wire Ø0.8, OD 8, 6 coils
What are the dimensions of a small torsion spring? · Hardware · basis: Close-wound helical torsion spring with two straight tangential legs; rate E d⁴ / (3667 D n) N·mm per degree
Long Earth Society build part. Pawl returns, diaphragm bias and belt tensioners on the LES rigs. 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
- Six close-wound coils of 0.8 wire, OD 8, ID 6.4, with two straight legs reaching 10 mm from the coil axis. Envelope 14 × 8 × 5.7.
- Torsion rate in N·mm per degree = E d⁴ / (3667 D n), E the wire's elastic modulus, D the mean Ø (7.2), n the coils.
- The ID (6.4) goes over an arbor; the legs bear on the two parts it sets against each other, such as a pawl and its frame.
Sizes
| feature | value_mm |
|---|---|
| wire Ø | 0.8 |
| OD / ID | 8 / 6.4 |
| coils | 6 |
| leg reach from axis | 10 |
| envelope | 14 × 8 × 5.7 |
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 |
|---|---|---|---|---|
| spring OD | OD (6–16) | pocket of the same Ø | socket | all |
| spring ID | OD − 2 × wire | guide rod or arbor of the same Ø | socket | all |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| Wikipedia | Spring (device) | web | CC BY-SA 4.0 (text) |
| McMaster-Carr | Compression springs (free STEP per part, for your own design use; no redistribution) | STEP, PDF | McMaster-Carr site terms verify |
| Lee Spring | Spring design formulas | web | Lee Spring site verify |
| Long Earth Society | Engine and rig 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
| torsion-d0.8-od8-l10 | torsion spring envelope: wire Ø0.8, OD 8, ID 6.4, legs reaching 10 mm from the axis, 6 coils | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=torsion-spring
How it fits
Connects to
Pawl 24 mm with a Ø3 pivot for the Ø40 ratchet…holds the pawl on the teethAlternatives
Compression springs, wire Ø0.5–1.6, OD 6–16linear returnYou might also need
Questions
How do I calculate a torsion spring rate?
N·mm per degree = E·d⁴ / (3667·D·n), with D the mean coil Ø and n the coils.
What arbor fits the torsion spring?
The coil ID is 6.4.