A machine such as a saw, jointer, planer, etc. is disclosed. The machine has cutting tool, a direct drive mechanism configured to move the cutting tool, a detection system adapted to detect the occurrence of an unsafe condition between a person and the cutting tool, and a reaction system adapted to mitigate the unsafe condition upon the detection of the unsafe condition by the detection system. An electrical signal is imparted on the cutting tool, and the signal is used to determine the occurrence of the unsafe condition. The direct drive mechanism is electrically isolated so that the electric signal may be imparted on the cutting tool. The electric isolation may be achieved through configurations such as insulated bearings, a substantially non-conductive housing, and a substantially non-conductive coupling joining two shaft portions.