WIRE MANIPULATION WITH AC WAVEFORM

An alternating current (AC) welding waveform, with two or more polarity changes during each molten metal droplet transfer cycle, is produced. The consumable welding electrode speed is mechanically controlled and the polarity is linked to known information about the electrode speed/direction, ensuring that at least two polarity changes are achieved per droplet transfer cycle. The arc polarity is concurrent with the change in direction of the electrode motion. The polarity can be changed based upon an actual speed of the electrode. Controlling the electrode motion and polarity in this way allows larger droplets to be created and higher deposition rates to be achieved at a lower frequency of shorting. The lower frequency of shorting also reduces wire feeder motor heating and wear, and increases contact tip life.