Lincoln Electric LN-9F GMA, LN-9 GMA manual Idle Roll Pressure Setting, Roll Wire Feeders

b-17 b-17

OPERATION

IDLE ROLL PRESSURE SETTING

The idle roll pressure is set at the factory backed out two turns from full pressure for 2-roll feeders, three turns from full pressure for 4-roll feeders. This is an approximate setting. For small wire sizes and alu- minum wire, the optimum idle roll pressure varies with type of wire, surface condition, lubrication and hard- ness. The optimum idle roll setting can be determined as follows:

2-ROLL WIRE FEEDERS

1.Press the end of the gun against a solid object that is electrically isolated from the welder output and press the gun trigger for several seconds.

2.If the wire "birdnests," jams or breaks at the drive roll, the idle roll pressure is too great. Back the pressure setting out 1/2 turn, run new wire through the gun, and repeat step 1. See Figure B.9.

3.If the only result is drive roll slippage, loosen the gun cable clamping screw in the gearbox conduc- tor block and pull the gun cable forward about six inches. There should be a slight waviness in the exposed wire. If there is no waviness, the pressure is too low. Increase the pressure setting 1/4 turn, lock the gun cable in place and repeat steps 1 and 2.

FIGURE b.9 – IDLE ROLL PRESSURE SETTING

FOR TWO-ROLL FEEDERS

PRESSURE

ADJUSTMENT

KNOB

4-ROLL WIRE FEEDERS

1.Release the incoming idle roll and perform the pressure setting procedure for two-roll wire feeders to set outgoing idle roll pressure.

2.After the outgoing pressure is set, determine how many turns away from full pressure the setting is.

3.Set both idle roll tensions to this setting. Engage both idle rolls before welding. For most applica- tions, best wire feeding will occur when both idle roll pressures are set the same.

LN-9 GMA and LN-9F GMA Wire Feeder