The movable roller applies pressure to the grooved roller via screw adjustable spring pressure. The adjustable spring screw should be adjusted to a minimum pressure that will provide satisfactory wire feed without slippage. If slipping occurs, and inspection of the contact tip reveals no wear, distortion or bum-back jam, the conduit liner should be checked for kinks and clogging by metal flakes and swarf. If this is not the cause of slipping, the feed roll pressure can be increased by rotating the adjustable spring screw clockwise. The use of excessive pressure may cause rapid wear of the feed roller, motor shaft, and motor bearings.
Please note that genuine D/F contact tips and liners should be used with D/F torches. Many non-genuine parts use inferior materials which can cause wire feed problems.