Lincoln International K2259-1 - Manual (Page 13)

Cobramatic ® Owner’s Manual - page 3
sure is added to the wire as it exits the tip.
Wire Retainer Bar
The design of the patented Cobramatic ® Wire Retainer Bar performs two very
important and very basic functions of the wire feeder: a) spool drag tension,
and b) wire maintenance on the spool.
The spool drag tension is set by lowering the wire retainer bar onto the sur-
face of the wire inside of the spool. The spring tension of the wire retainer
bar applies enough pressure on the spool so that when the gun trigger is
released, engaging the brake pall, the spool does not overrun kicking wire off
the spool.
Wire maintenance on the spool is performed by the applied pressure of the
wire retainer bar spread across the coiled wire on the spool. The replace-
able pad (P/N 437-0255) of the wire retainer bar is designed to hold the wire
on the spool, maintaining the smooth layering of the wire and keeping it from
jumping off, and possibly, electrically shorting to the cabinet chassis.
Welding Gun Connections
Control Cable
The 7-Pin “W” Clocked connector screws onto the mating receptacle on the
front panel of the wire feeder. This provides all electrical signals (motor volt-
age, potentiometer control & trigger) to and from the feeder to the gun.
Water Inlet (For Water Cooled Guns)
Front panel access to connect the water hose to the middle fitting on the
power block.
Wire Conduit Inlet
Front panel access to attach conduit to front of slave motor assembly.
Power Cable Inlet
Front panel access to attach power cable (air or water) to top of power block.
Guns with ring lugs, MUST connect to top bolt of power block.
Gas Inlet
Front panel access to attach gas hose to bottom fitting of power block.
Work Cable (Ground)
Connect a work lead of sufficient size and length between the proper output
stud on the power source and the work. Be sure the connection to the work
makes tight metal to metal electrical contact. Improper work lead connec-
tions can result in poor arc initiation and unsatisfactory weld results.
Consult welding power supply manufacturer for proper work lead sizing.
Section B Operation
General
The AC slave motor in the feeder runs at a fast, constant speed, but has very
low torque. It is always trying to feed more wire than the gun motor wants,
and when the gun motor gets all the wire it wants, the slave motor automati-
cally slows, preventing a bird’s nest. Because of the low torque produced
by the slave motor, a combination drag and electric brake system is used to
prevent wire overrun rather than relying on spindle tension alone. The spool
drag tension is produced by the patented Wire Retainer Bar mechanism to
keep the wire slightly taut. The 24 VDC gun “pull” motor is controlled by a
solid state speed control in the cabinet and through a potentiometer located
in the gun.