Use drive rolls with a V-groove and flat pressure rolls. ✓ Use knurled rolls only when friction in the liner causes smooth rolls to slip . with long, extremely curved cable assemblies. Knurled rolls give increased liner and contact tip wear. ✓ Check that the groove size is correct for the wire diameter. ✓ Apply the correct pressure on feed rolls. Too much pressure flattens the wire, resulting in feedings problems and higher liner and contact tip wear. Insufficient pressure may cause wire to slip in the feed rolls, resulting in irregular feeding and possible wire burnback