Always adjust the contact pressure of the feed rollers to the wire material and diameter used. Excessive pressure can cause abrasion, which leads to dust formation in the wire feed system. This promotes soiling, erosion and deformation of the wire and can change the wire geometry. As a result, the straightness of the wire is impaired, which reduces the quality of the weld seam and can lead to arc instability or even an overheated contact tip.
On the other hand, if the pressure is too low, the wire can slip in the feed system. This causes burnback, which results in uneven wire feeding and therefore poor weld seam quality.