| Lincoln Electric SVM127-A

B-10

OPERATION

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6.Loosen the ingoing guide tube clamping screw. Install the all steel guide tube through the rear brass block. Tighten the locking screw.

7.Replace the large ingoing guide tube into rear brass block.

8.Install the outgoing guide tube with its plastic insert through front brass block. Tighten the locking screw so its dog point goes into the groove in the O.D. of the guide tube.

NOTE: The drive rolls and guide tubes are stamped with the wire size ranges (in inches and

mm)for which they are designed. If a wire size other than that stamped is to be used, the drive rolls and guide tubes will have to be changed. Drive rolls stamped with a "(C)" or "(H)" suffix to the wire size range are recommended specifically for use with cored wires.

SETTING THE IDLER ROLL SPRING PRESSURE (2-ROLL WIRE DRIVES)

For Steel Wire, the idle roll pressure should be adjust- ed as follows:

The idle roll pressure indicator should be set to the proper wire size indication shown on the appropriate "solid" or "cored" side of the idler roll spring pressure nameplate. This setting is a starting point and may have to be changed depending upon type of wire sur- face condition, lubrication, and hardness.

The optimum idle roll setting can be determined when there are wire stoppages. If the wire "bird nests" between the drive roll and the guide tube, the idle roll spring pressure is set too high. When set, during a stoppage the drive rolls will slip. If the electrode is removed from the cable there will be a slight waviness in the electrode for about a foot beyond the slip marks on the electrode. If there is no waviness, the pressure is set too low.

For Aluminum Wire, the idle roll pressure should be adjusted as follows:

1.With low idle roll pressure, load the feeder so it’s ready for welding.

2.Run the feeder at a slow speed (about 100 IPM) and reduce the idle roll pressure until the idler roll stops rotating.

3.Slowly increase idle roll pressure until the idle roll just starts to rotate consistently with the drive roll without slippage, then add an extra 1/4 to 1/3 turn more idle roll pressure.

This pressure setting should be optimum for feeding and to avoid "bird-nesting" by allowing the drive roll to slip on the wire if a gun cable jam or stoppage occurs. If using harder or larger dia. aluminum wires, more idle roll pressure, if necessary, can be tolerated. However, if the pressure required to properly feed the aluminum wire also permits "bird-nesting," or if excessive slip- page results in aluminum pickup in the drive roll groove, the loading on the wire by the gun-cable or wire reel should be inspected and adjusted.

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Lincoln Electric SVM127-A service manual Setting the Idler Roll Spring Pressure 2-ROLL Wire Drives

Models: SVM127-A

OPERATION

SETTING THE IDLER ROLL SPRING PRESSURE (2-ROLL WIRE DRIVES)

LN-9 Wire Feeder