MK Products Cobramatic II - Manual (Page 11)

Cobramatic ® II Owner's Manual - Page 4
wear and will not contaminate the surface of the wire
T
ORCH
D
RIVE
R
OLL
A
DJUSTMENT
----------- IMPORTANT -----------
NOTE: Over-tightening of the drive rolls will cause excessive knurling and/or
deformation of the wire. When the complete system is set-up properly, feeding wire
out of the end of the torch and letting fall on the ground should
form a large uniform circle. If it forms a spiral or spring then
there is too much tension in the system, please refer to the Cabinet
Owners Manual for adjustment to the tension setting detailed there.
THIS IS THE NUMBER ONE CAUSE OF POOR WIRE FEED PERFORMANCE
---------------------------------------------
S
ECTION
B O
PERATION
G
ENERAL
D
ESCRIPTION
The Cobramatic ® II is an analog input version of the popular Cobramatic ® I
Cabinet and operates on the same basic principles. 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 high torque 24 VDC torch pull motor is controlled by a
solid state speed control and a potentiometer located in the torch, feeder
or remotely.
The solid state control circuit provides a wide range of operating conditions
and includes performance and fault isolation L.E.D. indicators. The wire feed
speed command can be derived from the cabinet, torch, or from a 0-10
volt analog external signal. A variety of input/output signals make it highly
suitable for automatic applications.
C
ONTROLS AND
S
ETTINGS
(S
EE FIG
. 4)
O
N
/O
FF
S
WITCH
Placing the switch in the “ON” position energizes the feeder circuitry and the
power indicator light.
W
IRE
S
IZE
S
ELECTOR
S
WITCH
The wire size selector switch changes the torque of the slave motor for the
wire you are using. When in the ".030-.035 Aluminum Only Position", the
slave motor produces approximately 1 1/2 lbs. inches and approximately 4 1/2
lbs. inches when in the "All Other Wires Position."
NOTE: Operating the cabinet with the switch in the wrong position will cause
wire feed diffi culties.
P
OSA
S
TART
C
ONTROL
When in the "ON" position, the wire feed command is derived from the Posa
Start potentiometer. After arc initiation, the wire feed speed is controlled by
the selected wire feed source, i.e., torch, cabinet, or remotely.
W
IRE
I
NCH
The Wire Inch button causes wire feed at the weld feed rate from the selected
source, independent of Posa Start and may be used to observe or time