POM Acetal for Drone Gimbal Gears and Linkages
A homopolymer polyoxymethylene (POM-H) compound for precision-machined or injection-molded drone gimbal gears, anti-backlash drive links, servo horn linkages, and self-lubricating bushings.
Key Features
- ✓Fatigue endurance 30 MPa at 10⁷ cycles — withstands millions of gimbal positioning cycles without gear tooth fatigue failure
- ✓Coefficient of friction 0.20–0.30 dry — self-lubricating, eliminates grease that attracts outdoor dust
- ✓Moisture absorption 0.2% — gear mesh backlash stable across all seasonal humidity conditions
- ✓Isotropic mold shrinkage 1.8–2.0% — predictable gear tooth profile accuracy after injection molding
- ✓Operating range -40°C to +100°C — gimbals remain operational in winter mountain surveying conditions
- ✓Compatible with Mod 0.3–1.5 gear cutting for the small module sizes used in drone gimbals
Specifications
| Parameter | Value |
|---|---|
| Density | 1.41–1.42 g/cm³ |
| Polymer type | Polyoxymethylene homopolymer (POM-H) |
| Flexural modulus | 3,000–3,200 MPa (ISO 178) |
| Tensile strength | 70–75 MPa (ISO 527) |
| Fatigue endurance limit | 30 MPa (10⁷ cycles, R=−1) |
| Mold shrinkage (isotropic) | 1.8–2.0% |
| Operating temperature range | -40°C to +100°C |
| Recommended gear module range | Mod 0.3–1.5 |
| Coefficient of friction (dry, vs steel) | 0.20–0.30 |
| Equilibrium moisture absorption (23°C, 50%RH) | 0.2% |
FAQ
POM injection molding of spur gears is reliable down to Mod 0.3 (0.3 mm module, approximately 85 teeth per 25 mm pitch diameter) under controlled molding conditions. Gate placement, cooling uniformity, and mold temperature (80–100°C) are critical for tooth profile accuracy at small modules. Mold steel must be hardened to >50 HRC to withstand ejection forces on fine tooth tips without wear. For modules below 0.5, consider machining POM gear blanks from rod stock as an alternative to molding — machined gears offer superior tooth profile accuracy (DIN 7 vs DIN 9–11 for molded parts), though at higher unit cost for large volumes.