The slip clutch mechanism allows the cutter to get past obstacle and continue cutting when an obstacle is hit. This feature also prevents damage to the gears inside the gearbox and other internal parts. Other rotary cutters use a sheer pin which simply sheers and stops the machine where it is without damaging the gears or drive line. However, a new sheer pin has to then be put in to continue operation. A slip clutch allows for field mistakes without damaging the machine and without having to stop and replace parts.