The idler roller part of the system may be smooth or
have grooves for the specific wire type and diameter. The
idler roller must be adjusted to feed the wire into the
roller grooves without slippage or flattening the wire.
Inlet guides are used to feed the wire into the drive
rollers. Outlet guides are also used to feed the wire from
the drive rollers into the gun cable or cable adapter.
Guides are made of a variety of materials. Hard wires
(steel, stainless steel, Inconel, etc.) will wear the guides
quite rapidly and require frequent replacement. They are
adjusted as close to the roller as possible. This prevents
the wire from “birdnesting” in the area between the
rollers and guides. See Figure 3-20.
Wire Wipers
This accessory is attached to the inlet side of the
drive roll system, as shown in Figure 3-21. It usually
consists of a piece of felt material that is closed where the
wire passes through it. A small amount of commercial
fluid may be placed on the felt to lubricate the wire as it
passes through. This will extend the life of the guides and
the cable liners in the gun cable. Use the wiper only when
welding on the specific materials defined by the manu-
facturer of the fluid. Do not over-lubricate.
Wire Feeder Maintenance
Wire feeders require very little maintenance to keep
them operating properly. As with any electrical device,
34 Gas Metal Arc Welding Handbook
Figure 3-16. Adjusting the pressure roller will increase or
decrease the amount of cast in the wire. (Miller Electric Mfg. Co.)
Pressure
roller
Figure 3-17. Two-roll wire feed system. Note the feed roll has two
grooves to adapt to different wire sizes. (CK Worldwide, Inc.)
Figure 3-18. Four-roll wire feed system. These systems are
used where precision drive of the filler wire is required. Note
that rollers have the groove type and wire size stamped on
them. (Miller Electric Mfg. Co.)
U-groove
for
soft wires
V-groove
for
hard wires
Figure 3-19. Wire drive rollers have different groove designs for
hard or soft wires. Using the incorrect groove will cause wire
feeding problems.
Type of
groove
Wire size