| Lincoln Electric SVM127-A

B-11

OPERATION

Return to Section TOC

Return to Master TOC

CHANGING WIRE FEED ROLLS AND GUIDE TUBES FOR 4-ROLL WIRE FEED- ERS

To change drive rolls on a 4-roll wire feeder, refer to Figure B.4 and perform the following steps:

1.Release both quick release levers.

2.Remove clamping collars from both drive shafts.

3.Install one drive roll and replace clamping collar. Tighten screw.

4.Slide the middle guide tube into place. Do not tighten set screw.

5.Install second drive roll and replace clamping col- lar. Tighten screw. (Note: The middle guide tube may need to be pushed up tight against the first drive roll to allow room for installing the second roll.)

6.Center the middle guide tube and lock in place with its set screw.

7.Remove the idle roll quick release pins - install idle rolls. Replace pins.

NOTE: The aluminum wire drive roll kits have one- piece drive rolls and idle rolls with a larger chamfer on one side, instead of gear teeth. This larger chamfer side must face the gearbox when installed. The side with the smaller chamfer and wire size stencil must be installed facing out.

8.Loosen the ingoing guide tube clamping screw. Install the all steel guide tube. The guide tube should be slid in until it almost touches the drive rolls. Tighten the locking screw.

9.Install the outgoing guide tube with its plastic insert through the 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)” suffix to the wire size range are recommended specifically for use with cored wires.

SETTING THE IDLER ROLL PRESSURE (4-ROLL WIRE DRIVES)

Because every feeding situation is different, the 4-roll wire drive does not have graduated markings with wire sizes indicated on it. A recommended starting pressure is indicated below for each applicable wire size and type. Depending on the particular application, these starting pressures may need to be adjusted up or down. Some of the vari- ables that affect tension settings are type and brand of electrode, surface condition, lubrication, harness, type and length of cables and conduits, routings of cables and conduits, and drive roll wear.

In most applications, the front and rear drive roll pressures should be adjusted the same. To adjust, start by releasing both "quick release" arms. Tighten the tension adjusting screws to full pres- sure and then back off per the particular instruc- tions for your electrode size and type as outlined below.

For Steel Wire
1. .030-.052" solid-----------	4 turns from maximum
.045-.052" cored--------	12 turns from maximum

The optimum pressure setting can be determined when there are wire stoppages. If the wire "birdnests" between the rolls and guide tubes, the pressure is too great. When properly set, during a stoppage the drive rolls will slip. If the electrode is removed from the cable there will be a slight wavi- ness in the electrode for about a foot beyond the slip marks on the electrode. If there is no wavi- ness, the pressure is too low.

2.1/16" solid-----------2 to 4 turns from maximum

.062" cored----------7 to 8 turns from maximum

These settings should be accurate unless the elec- trode is unusually soft or the feeding path is exces- sively long or curved.

3. .068-3/32" solid----	8 to 10 turns from maximum
.068-.120" cored----	6 or 7 turns from maximum

Larger wire settings are accurate for nearly all applications. Some unusual circumstances will require "fine tuning."

Return to Section TOC

Return to Master TOC

Lincoln Electric SVM127-A service manual Setting the Idler Roll Pressure 4-ROLL Wire Drives

Models: SVM127-A

OPERATION

SETTING THE IDLER ROLL PRESSURE (4-ROLL WIRE DRIVES)

LN-9 Wire Feeder