Wire Feed Stability

Wire feed stability is important for arc stability. Unstable feeding results in an unstable arc with more spatter and less straight weld beads. The graph below shows the velocity frequency scale measured during 20 minutes of welding.

Wire feed stability

Actual wire feed speed is measured at the welding torch. Between the feeding rolls and torch, the wire, together with the liner, acts as a spring. This is why wire speed is lower than set value when feeding force suddenly increases, and higher when feed force suddenly decreases. If slip occurs between feeding rolls and wire, the actual wire feed speed is more severely affected. A wide, low curve represents unstable feeding, while a small, high curve shows stable feeding.

Wire feed stability

Standard copper-coated wire (left), OK AristoRod™ (right)

The graphs above were obtained by measuring up to 330 minutes of welding, for OK AristoRod™ and copper-coated MIG/MAG wire. Clearly, feeding is much more stable for OK AristoRod™ and there is substantial speed variation with the copper-coated wire. With OK AristoRod™, the test was completed over the full period of 330 minutes, while the test with the copper coated wire was abandoned after 220 minutes due to burnback of the wire at the contact tip.