Lincoln Electric IM502 LN-742H Wire Feeder - Manual (Page 19)

B-5 OPERATION B-5
5. Use the clamping collar and hex head screw to
install the roll on the output shaft. Certain size drive
rolls consist of two roll halves, and may contain a
spacer. If the drive roll you are installing contains a
spacer, the spacer fits between the two halves of
the drive roll. Double grooved drive rolls are to be
installed with side stenciled for correct wire size
facing outward and with slotted spacer on top of
roll. Tighten the hex head screw.
6. Loosen the molded hand-screw on the front of the
wire drive and pull the gun connector out of the
connector block. The guide tube provided in the
gun connector is for .045
” (1.2mm) or smaller wire
sizes (marked with one ring). If larger wire sizes
are used, remove and replace the guide tube with
the larger hole guide tube (marked with four rings)
which is provided in the storage hole of
appropriate capacity wire drive faceplates (near
motor). The guide tube is secured with a set
screw on the bottom of the brass hex so the guide
tube is flush with the incoming end of the gun
connector.
7. Back out the guide tube clamping screws.
Remove the old guide tubes, if installed.
8. Insert the longer guide tube into the rear hole and
the other guide tube through the front hole. The
fine wire chisel point end of the guide tube must
have the larger radius end next to the drive roll.
See Figure B.2. Push the guide tube back as far
as it will go and tighten the clamping screw. Insert
the incoming guide tube as far back as it will go
and tighten the clamping screw. The clamping
screws are dog points. When the guide tubes are
properly installed these dog points will lock into
the annular grooves in each of the guide tubes.
9. Re-install the gun connector into the conductor
block and tighten the molded hand-screw.
10. Re-latch the idle roll pressure arm.
11. Set the idle roll pressure as detailed in the Idle
Roll Pressure Setting procedure detailed later in
this section.
CHANGING DRIVE ROLLS FOR FOUR-
ROLL WIRE FEEDERS:
To change drive rolls on a four-roll wire feeder, refer to
Figure B.3 and perform the following steps:
1. Turn off welding power source.
2. Remove the gun and cable.
3. Open both quick release levers by moving the
levers outward and pulling them toward you.
4. Loosen the thumb screws holding the guide tubes
in place. Remove the incoming guide tube, if
installed.
5. Remove the hex head screws and clamping
collars from the output shafts. Remove the drive
rolls and middle guide tube.
6. The new rolls to be installed are stenciled with the
wire size that will be fed. An “ A ” after the number
indicates aluminum wire. Remove the rolls from
the kit and wipe them clean. Wipe the output
shafts and locating shoulders clean.
7. Install one roll onto the output shaft closest to the
incoming side of the feeder clamping collar and
hex head screw. Certain size drive rolls consist of
two roll halves, and may contain a spacer. If the
drive roll you are installing contains a spacer, the
spacer fits between the two halves of the drive
roll. Double grooved drive rolls are to be installed
with side stenciled for correct wire size facing
outward and with slotted spacer on top of roll.
Tighten the hex head screw.
8. Install the middle guide tube, but do not tighten at
this time. When installing a 0.035 ” middle guide
tube the larger radius should be aligned towards
the drive roll. Slide the guide tube up against the
installed drive roll.
9. Install the second drive roll on the remaining shaft
the same way as the first. Center the middle guide
tube between the rolls and tighten the
thumbscrews holding it in place.
10. Loosen the molded hand-screw on the front of the
wire drive and pull the gun connector out of the
connector block. The guide tube provided in the
gun connector is for .045
” (1.2mm) or smaller wire
sizes (marked with one ring). If larger wire sizes
are used, remove and replace the guide tube with
the larger hole guide tube (marked with four rings)
which is provided in the storage hole of
appropriate capacity wire drive faceplates (near
motor). The guide tube is secured with a set
screw on the bottom of the brass hex so the guide
tube is flush with the incoming end of the gun
connector.
11. With the gun connector removed, back out the
screws for the outgoing guide tube.
12. Install the outgoing guide tube in the front hole.
Be certain that the proper plastic insert is used.
For proper installation of the outgoing guide tube
insert, refer to Figure B.3. The fine wire chisel
point tube must have largest radius next to drive
roll. Tighten in place.
13. Re-install the gun connector into the conductor
block and tighten the molded hand-screw.
LN-742 & LN-742H