Section 7
Tighten the torch pressure adjusting knob so the wire will be picked up and fed through the contact tip. Proper tension is achieved when wire does not slip if a small amount of pressure is added to the wire as it exits the tip.
6.3 PRE-SETTING SLAVE MOTOR TENSION
All Cobramatics have preset adjusting nuts which enables spools of the same wire diameter and type to be changed without further pressure adjustment after initial
To preset the slave motor tension bottom out the pressure adjusting knob by turning it completely clockwise.
Prevent the wire spool from turning and using a 9/16" wrench adjust the preset nut until the slave motor stalls.
Correct pressure will now be achieved by simply bottoming out the pressure adjusting knob.
6.4 WIRE GUARD
The Cobramatic® Wire Guard is designed to keep the welding wire from jumping off the spool inside the wire feed cabinet. When the trigger is released and the brake engages, especially when using a new spool that is heavier towards the outside, the spool will tend to rotate more against the spindle drag adjustment.
However since the wire is held by the slave motor it will not move and could subsequently jump off the back of the spool and become lodged in the brake mechanism, or jump off the front of the spool and electrically
The wire guard is designed to run inside the spool on top of the wire, and when the brake is engaged the wire guard will hold the wire onto the spool. The wire guard is made of a heavy woven nylon material that is resistant to wear and will not contaminate the surface of the wire.
OPERATION
7.1 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 torch motor wants, and when the motor gets all it wants, it slows the slave motor preventing a bird’s nest. Because of the low torque produced by the slave motor, a brake system is used to prevent wire overrun rather than tension. The drag adjustment in the spindle is used to keep the wire slightly taut, so it will not unspool while feeding wire. The 24 VDC torch pull motor is controlled by a solid state speed control and a potentiometer located in the torch.
7.2 FEEDER CONTROLS
7.2.1 ON/OFF SWITCH
Placing the switch in the “ON” position energizes the feeder circuitry and the power indicator light.
7.2.2 WIRE SIZE SELECTOR SWITCH
The wire size selector switch changes the torque of the slave motor for the