Shielding Design for Torsion-Resistant Cables
Shield integrity under torsion is critical for robot cables carrying high-speed data signals. An ineffective shield can fracture into needle-sharp strands that puncture insulation and cause short circuits .
Optimal Shielding Design :
Helically wound served shield: 85-90% optical coverage
Counter-rotating strand layers: Balances torque
Individually foiled data pairs: Al/PET foil with dedicated drain wire
Shield Comparison :
Shield Type | Characteristics | Best For |
|---|---|---|
Braided Copper | 90%+ coverage, excellent EMC | Static applications |
Spiral-Wrapped | Ideal EMC/mechanical balance | Dynamic torsion applications |
Foil (Al/PET) | Lightweight, 100% coverage | Data pair shielding |
Critical Requirement: Any twisted pair must be individually foiled with a dedicated drain wire in full physical contact with the foil. Avoid "floating" shields that can break under torsion .
