Tapered metal rod for spooling lights cables and grip kit — prevents kinks and storage damage. Standard diameters 2–4 inches; check regularly before shooting.
On every major production, hundreds of meters of cable lie around — lighting control cables, DMX lines, power feeds. If you simply wind them onto a reel, after two or three takes you'll have a tangled mess of cables and damaged insulation. This is where the mandrel comes into play: a conical metal rod onto which you wind the cables tightly. This sounds trivial, but it's essential for grip logistics.
The mandrel prevents two critical problems. First: kinks. If you wind a cable haphazardly or lay it in tight loops, permanent kinks form in the insulation — short circuits and failures are then only a matter of time. The mandrel, due to its conical shape, forces a uniform radius, minimizing bending stress. Second: storage wear. Cables that are always stored the same way (e.g., rolled to the same diameter) fatigue less and last longer. Standard diameters range from 2 to 4 inches — you choose the size depending on the cable type. Thinner DMX and lighting control cables fit on 2-inch mandrels, thicker power cables need 3 to 4 inches.
In practice: The best time to wind cables is during teardown — when the electrician and grip master are coiling the lines. A systematic team fills mandrel after mandrel and stores them neatly in cable reels or on open racks. Before each new shooting day, check the mandrels for dents, rust, and deformations — a bent mandrel destroys cables just as effectively as no mandrel at all. If a production moves 50+ cables daily, well-maintained mandrels drastically reduce the error rate. Dragging or damaged cables are production killers — a few euros for solid mandrels save you hours of troubleshooting.
Practical tip: Color-code your mandrels by diameter or cable type so the grip can quickly grab what they need. And store them dry — rust spots on a mandrel can rub off onto insulated cables and then become a permanent contact risk.