Spark erosion system for reducing the height of a honeycomb seal

摘要

An apparatus for machining metal substrates such as honeycomb seals is provided. The apparatus includes a spindle unit including a motor and shaft. The motor is used for rotating the spindle shaft about its longitudinal axis. The spindle shaft is connected to a power source which converts it and a tool head secured thereto to an electrode. The electrode is positioned in close proximity to a rotating workpiece such that an arc is formed between it and the workpiece. Power to the electrode is adjustable to control the rate of metal removal from the workpiece. Circuitry is used to cut off power to the spindle shaft when the current from the power source exceeds a certain amperage for an extended period of time (such as three seconds to prevent nuisance cut off). The circuitry also allows arcing between the electrode and the workpiece without cutting off power to the spindle shaft.