3D printed spring generator
Generate a helical compression spring from its wire, diameter, length and coil count
A helical compression spring built as one swept solid, so it always comes out as a single connected body rather than a stack of rings. You set the wire diameter, the outside diameter, the free length and the coil count; the thing that decides whether it prints — the gap left between neighbouring coils — is what falls out of them, and it is derived and reported rather than left to the plate. Ask for a length that cannot hold that many coils apart and it is raised to the shortest one that can, and says so. Closed ends stand square; ground ends are cut flat and land the height exactly. Download a print-ready STL or 3MF.
How the 3D printed spring generator works
What you can adjust
- Wire Ø — 0.2–12 mm
- Outer Ø — 2–200 mm
- Free length — 2–300 mm
- Coils — 2–60
- Ends — Open · Closed · Closed & ground
- Hand — Right · Left
- Wire section — Round · Square
Spring settings that print
The generator’s starting values, and why each one is set that way.
| Setting | Start with | Why |
|---|---|---|
| Wire Ø | 1.6 mm | The thickness of the coil. Thicker wire makes a stiffer spring. |
| Outer Ø | 12 mm | What a caliper reads across the spring. |
| Free length | 30 mm | The uncompressed height. If the coils cannot fit apart, it is raised and the panel says so. |
| Coils | 8 | More coils in the same length leave a smaller gap between them. |
| Ends | Closed & ground | Ground flat, it stands on about nine times the bed contact of a merely closed end, so the nozzle does not knock it over. |
| Wire section | Round | Square prints better: a round wire tapers to a sliver at every layer boundary. At the same size, square has about 27% more material, so it is stiffer. |
Printing a spring that works
- Watch the coil gap. Coil gap is worked out from the other values and checked against your printer’s minimum wall. Too narrow and the coils weld together, so the spring prints solid.
- Mind the spring index. Spring index is the mean Ø divided by the wire Ø (6.5 by default). Real springs run from 4 to 12; the generator does not go below 3.
- Print it standing up. With ground ends it stands on a flat face and the height comes out exact. No supports.
- Pick a tough filament. PLA takes a set under load; a PETG or nylon spring springs back for longer.
Spring questions
Can you 3D print a spring?
Yes, a compression spring for light loads. This generator builds it as one body and works out the coil gap that decides whether it prints.
What is spring index?
The mean coil diameter divided by the wire diameter. With a 12 mm outside and 1.6 mm wire it is 6.5. The lower it is, the stiffer the spring and the harder it is to wind.
Round or square wire?
Square for printing: every layer is full width and the bottom face lands flat. Round is the default because it is the classic spring; at the same size, square is stiffer.