Xem Studiomeasured geometryCompression springs, wire Ø0.5–1.6, OD 6–16
How do I calculate the rate of a compression spring? · Hardware · basis: Helical compression spring with closed ends; rate k = G d⁴ / (8 D³ n), D = OD − d
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
- Envelopes at exact wire Ø, OD, ID (OD − 2 × wire) and free length, with closed (flat-ring) ends.
- Rate k = G d⁴ / (8 D³ n): G the shear modulus of the wire, d the wire Ø, D the mean coil Ø (OD − d), n the active coils. Halving the coils doubles the rate.
- Spring index D/d between 4 and 12 is makeable, 6–9 comfortable; these are 9 except the 0.5 × 6 at 11.
- Solid height is about (n + 2) × d; usable deflection about 0.8 × (free length − solid height). A pocket for one is drawn at the OD and a guide rod at the ID (see Mating features).
Sizes
| file | wire Ø | OD | ID | free length | coils | index D/d |
|---|---|---|---|---|---|---|
| compression-d0.5-od6-l20 | 0.5 | 6 | 5.0 | 20 | 8 | 11.0 |
| compression-d0.8-od8-l25 | 0.8 | 8 | 6.4 | 25 | 10 | 9.0 |
| compression-d1-od10-l30 | 1.0 | 10 | 8.0 | 30 | 10 | 9.0 |
| compression-d1.2-od12-l40 | 1.2 | 12 | 9.6 | 40 | 12 | 9.0 |
| compression-d1.6-od16-l50 | 1.6 | 16 | 12.8 | 50 | 10 | 9.0 |
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 5 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| compression-d0.5-od6-l20 | compression spring envelope: wire Ø0.5, OD 6, ID 5, 20 mm free length, closed ends, 8 coils | STEP · STL |
| compression-d0.8-od8-l25 | compression spring envelope: wire Ø0.8, OD 8, ID 6.4, 25 mm free length, closed ends, 10 coils | STEP · STL |
| compression-d1-od10-l30 | compression spring envelope: wire Ø1.0, OD 10, ID 8, 30 mm free length, closed ends, 10 coils | STEP · STL |
| compression-d1.2-od12-l40 | compression spring envelope: wire Ø1.2, OD 12, ID 9.6, 40 mm free length, closed ends, 12 coils | STEP · STL |
| compression-d1.6-od16-l50 | compression spring envelope: wire Ø1.6, OD 16, ID 12.8, 50 mm free length, closed ends, 10 coils | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=compression-springs
How it fits
Goes in or on
Metric shafts Ø3 to Ø10 with D-flats and clip…guide rod at the spring IDAlternatives
Extension springs, wire Ø0.6 and Ø1.0pulls instead of pushesYou might also need
Questions
How do I calculate a compression spring rate?
k = G·d⁴ / (8·D³·n), with d wire Ø, D = OD − d, n active coils, G the wire's shear modulus.
What is the solid height?
About (coils + 2) × wire Ø: the 10-coil, 1.0 wire, 30 long spring is about 12 mm solid.