Cable corkscrewing is exactly what it sounds like—damage to a cable that causes it to look just like a corkscrew, with small tight twists rather than a circular, smooth design. It occurs most often in motion applications, where constant flexing and repetitive motions can cause stress and deform the cable, often destroying the core.
As a cable moves within a cable carrier or on a robot arm, for example, its conductors also move, shifting from the original stranding design. These displaced conductors also damage the jacket, causing both internal and external cable components to become twisted.
The primary cause for this problem is in how the cables are designed. Cables that are bundled rather than layered tend to have less corkscrewing issues. Layering a cable is easy, as the conductors are simply placed around the core in a circular fashion. But this means these conductors shift and compress easily, releasing torsional stress. Bundled designs feature more inner strength and stability.
In addition, core design and jacketing can help prevent corkscrewing. The stronger and more tensile the core, the less likely it will bend and twist as the cable is subjected to continuous motion. Having a reinforced jacket that firmly holds the cable together is also key to maintaining cable design.
Finally, installation can impact a cable’s life. If not allowed to lie within the cable track or robotic arm the natural way, it tends to twist out of its natural shape. In addition, securing a cable too tightly or too much can cause it to quickly bend out of shape.