Sensor detects broken tool

Keywords Drilling, Sensors

A non-contact sensor detects broken drills in drill bushing applications. The MagicEye, a patented ferrous-object sensor, from A + P Research, Ann Arbor,Michigan, overcomes the limitations of conventional wand or "whisker" tool sensors that cannot touch the drills because it stays inside the bushing at home position.

The new sensor has a sensing distance greater than 0.25in. from the surface of a tool. The sensor can be flush-mounted on a steel plate at the exit side of the drill bushing.

When the tip of a drill exits a drill bushing, the sensor sends a pulse to a controller that measures the interval between the cycle start signal and the sensor output. A broken drill produces a longer time interval, which the controller detects. The sensor is only 0.14in. thick and 0.36in. wide and is encapsulated in a stainless-steel casing, completely sealed and watertight.