LEARN · 2026-10-06
The complete guide to 3D-printed gears: materials, tolerances and processes
How to print gears that work: PLA, PETG, nylon, resin and SLS / MJF compared for wear and strength, plus backlash, bore compensation, orientation and finishing tips.
Pick the right process
| Process | Min. module | Strengths | Best for |
|---|---|---|---|
| FDM (PLA / PETG) | m1 | Cheap, fast | Prototypes, light loads |
| FDM (nylon / PC) | m1 | Tough, wear-resistant | Functional parts |
| SLA resin | m0.5 | Fine detail, smooth | Small precise mechanisms |
| SLS / MJF PA12 | m0.8 | Wear-resistant, isotropic, no supports | Production-grade gearboxes |
Tolerances and compensation
- Backlash: FDM 0.1–0.15 mm, SLA 0.05 mm, SLS 0.1 mm (tooth-thickness reduction per gear).
- Bores shrink on FDM — open them by 0.2 mm, or ream to size.
- Add 0.05–0.1 mm to the centre distance to avoid binding.
- D-cut bores transmit torque better than round ones; pair set screws with captive hex nuts.
Orientation and slicer settings
- Print gears flat (axis vertical) for the most accurate tooth form.
- Use 3–4 perimeters so teeth are solid wall.
- Slow outer walls; keep the Z seam off the tooth tips.
- Helical and herringbone gears print flat without supports and run quieter.
Lubrication and life
Use PTFE or silicone grease — petroleum oils attack some plastics. Mixing materials in a pair (e.g. nylon on POM) reduces wear and noise. For more load, increase the module before the face width.
FAQ
How long do PLA gears last?
A long time at low speed and load, but PLA softens above ~50 °C — use PETG, nylon or SLS near motors or under load.
Why do my printed gears bind?
No backlash, an exact theoretical centre distance, or elephant's foot. Add 0.1 mm backlash and trim the first layer.
I need many identical gears.
SLS / MJF packs the whole build volume in one run — lower unit cost and consistent quality. Send the model to Orinovate for a quote.