Patent ID: 8710395

Claim:
An automated method for controlling a plasma arc torch when cutting a hole feature in a workpiece, the method comprising: initiating a cutting current in the plasma arc torch; establishing a first command for extinguishing a plasma arc at a first location along a cut; establishing a second command for varying a motion of the plasma arc torch, the second command independent of the first command; establishing a negative time offset for determining initiation of a current ramp down at a second location along the cut, the second location preceding the first location, wherein the negative time offset is a sum of: (i) a delay between the first command and initiation of the current ramp down; and (ii) a time between initiation of the current ramp down and extinguishment of the plasma arc; cutting the workpiece using the plasma arc torch; and terminating the cut by: initiating the current ramp down at the second location, such that the cutting current is extinguished by the time the plasma arc torch reaches the first location; and varying the motion of the plasma arc torch according to the second command.