ESAB A6 GMD User manual

333 533--011 9704
A6 GMD
Joint tracking equipment
Simplified service manual

LIST OF CONTENTS Page
TECHNICAL DESCRIPTION 4..............................
INSTALLATION 8..........................................
OPERATION 10............................................
MAINTENANCE 12.........................................
DIMENSION DRAWING 13...................................
DIAGRAM 16...............................................
SPARE PARTS LIST A6 GMD 19.............................
Rights reserved to alter specifications without notice.

-- 3 --mvarnen1
WARNING
ARC WELDING AND CUTTING CAN BE INJURIOUS TO YOURSELF AND OTHERS.
TAKE PRECAUTIONS WHEN WELDING. ASK FOR YOUR EMPLOYER’S SAFETY
PRACTICES WHICH SHOULD BE BASED ON MANUFACTURERS’ HAZARD DATA.
ELECTRIC SHOCK -- Can kill
SInstall and earth the welding unit in accordance with applicable standards.
SDo not touch live electrical parts or electrodes with bare skin, wet gloves or
wet clothing.
SInsulate yourself from earth and the workpiece.
SEnsure your working stance is safe.
FUMES AND GASES -- Can be dangerous to health
SKeep your head out of the fumes.
SUse ventilation, extraction at the arc, or both, to keep fumes and gases from
your breathing zone and the general area.
ARC RAYS -- Can injure eyes and burn skin.
SProtect your eyes and body. Use the correct welding screen and filter lens
and wear protective clothing.
SProtect bystanders with suitable screens or curtains.
FIRE HAZARD
SSparks (spatter) can cause fire. Make sure therefore that there are no
inflammable materials nearby.
MALFUNCTION
SCall for expert assistance in the event of malfunction.
READ AND UNDERSTAND THE INSTRUCTION MANUAL BEFORE
INSTALLING OR OPERATING THE EQUIPMENT
PROTECT YOURSELF AND OTHERS!

-- 4 --
cga9d1ea
TECHNICAL DESCRIPTION
The A6 GMD joint tracking equipment is used for positioning and joint--tracking of
automatic welding machines with all types of joints in which there is a guide edge for the
sensor finger to follow. The equipment has been designed to suit standard ESAB slides, and
can control either one or two servo motors simultaneously.
Technical data
Joint tracking equipment A6 GMD
Control and operating voltage 42V AC 50--60 Hz
Power requirement 460 V A
Motor regulator, type Switched four--quadrant
Stator voltage, joystick control 40 V DC
Field voltage, separately excited motor 48 V DC
Enclosure type IP 53
Max. ambient temperature +45_C
Wei
g
hts:
W
e
i
g
h
t
s
:
Sensor and cross--sadle with mount 2.2 k
g
S
e
n
s
o
r
a
n
d
c
r
o
s
s
-
-
s
a
d
l
e
w
i
t
h
m
o
u
n
t
Joint tracking unit
2
.
2
k
g
4.5 kg
J
o
i
n
t
t
r
a
c
k
i
n
g
u
n
i
t
Sensor finger
4
.
5
k
g
0.6 kg
Remote control unit 2kg
Working range sensor, radially 360˚4mm
The figure below shows the working range and setting speed of the equipment.
For the A6 servo slide, see Simplified service manual no. 334 346--001.
dga9d008
Normal gearing
Reversed gearwheels
cm/min Welding speed
Welding speed/Angular deviation
Maximum angular deviation of the weld joint in relation to the preset welding speed.

-- 5 --cga9d1ea
The A6 GMD comprises:
1. Sensor, order no. 416 688--880
2. Control cable (2 m), order no. 416 749--887
3. Cross saddle for sensor, order no. 416 739--880
4. Control unit, order no. 416 065--880
5. Joint tracking unit, order no. 416 066--880
dga9b005
For welding column and boom units the control box and the control cable (points 4 and 5
above) are replaced by product specific items.
Extra equipment for A6 GMD
SSensor finger, order no. 416 719--001 (L=100 mm)
SSensor finger, order no. 416 719--002 (L=150 mm)
SSensor finger for internal and external corners, order no 418 091--880
SAuxiliary control power transformer for separate power supply from mains:
190, 220, 380, 415, 440, 500 V 50 Hz
200, 230, 380, 415, 440, 500 V 60 Hz, to secondary 42V, 660 VA
see order no. 148 636--002
SCable3x2.5mm
2, for transformer, order no. 2626 134--04
SSensor cable with 90_--contact, order no. 418 091--887
SRubber guard bellows, order no 412 013--001
SBracket for control box 433 762--xxx. The bracket is available in different applications.

dga9d003
-- 6 --
cga9d1ea
ESAB standard servo slides for A6 GMD
SA6 servo slide of ball bushing type with permanently excited 42 V DC motor,
see 334 333
SA6 motorized slide, long travel, with sliding support and A6 VEC motor 42 V DC --
4000 rpm -- ratio 74:1, see 334 426
SMotor cable, order no. 417 310--xxx.
The cable is available in different lengths, see spare parts list.
Controls and connections
Control box
1. Indicating lamp, red
Lamp for joint tracking control. When lit, indi-
cates that the sensor finger is outside its
working range (vertically). The automatic
control devices are now blocked.
2. Illuminated pushbutton, orange
Selection of high speed for manual operation.
3. Joystick
For manual control of servo slide motions:
Up/Down and Left/Right. The joystick is always
in command. When the indicating lamp is out any
manual motion downwards is blocked.
4. Selector switch, 5 positions
Selection of joint location and joint tracking modes:
SManual pre--setting
SVertical and horizontal joint tracking
SVertical and horizontal joint tracking with search/location to right
SVertical and horizontal joint tracking with search/location to left
SVertical joint tracking
5. Indicating lamp, green
Power On indication.

dga9d005
-- 7 --cga9d1ea
Joint tracking unit -- rear panel
1. Socket, 4--way
for connection of horizontal slide motor
2. Socket, 4--way
for connection of vertical slide motor
3. Socket, 8--way
for connection of guide finger
4. Socket, 23--way
for connection of control unit
5. Power supply, 42 V
6. Control circuit fuse,
10 A anti--surge (1 pc)
7. Switch
for selection of horizontal slide
direction of travel
8. Socket, 3--way
for joint memory unit (MEMO)
9. Switch
Power supply, On/Off
10. Spare socket
11. Socket, 8--way
for connection of Limit switch
Sensor
1. Sensor with cable connection for joint tracking unit and fixing device in front for the fit-
ting of different sensor fingers.
2. Sensor fingers.
3. 2 stop screws for adjustment of the horizontal flexibility of the of the fingers. The screws
are intended for the setting of the different joint types.
dga9d014

dga9d019
-- 8 --
cga9d1ea
INSTALLATION
1. For dimensions and settings, see Dimensions on page 13.
2. Connection, see page 16
Check that the necessary power supplies, of the correct voltage, are available.
SWhen using a power source of one of the types LAE 800 -- 1000 -- 1250 -- 1600,
connected for 42 V control voltage, the necessary power can be obtained from the
standard automatic welding machine -- see terminal PEG1.
SWhen suitable voltage is unavailable or when an LAH 500--630 42 V power source
is used, there must always be installed a 42 V intermediary transformer for the volt-
age supply to the A6 GMD (see ”Accessories” section).
3. See page 6 for details of the controls.
Commissioning of the joint tracking equipment
WARNING!
N.B. When the sensor is to be exchanged, the joint tracking equipment (ordering no
416 066--880) must be adapted to the supplied sensor (ordering no. 416 688--880).
N.B. In case the adaptation does not take place on installation, the joint tracking
function can be seriously impaired and mechanical damages may come about on the
control and contact devices through collission with the workpiece.
Trimming of the sensor voltage
1. Dismount the front panel of the control unit.
2. In case more space is needed for measuring, the regulator boards can be removed.
3. Connect a voltmeter to measuring point TP1--TP0.
4. Run the vertical slide downwards by way of the remote control unit until the tip of the
sensor finger contacts a flat base and the warning lamp on the remote control unit goes
out.
5. Set the selector switch on the remote control to vertical tracking.
6. Move the finger tip aside as far as possible.
7. Check the value on the voltmeter and adjust with
potentiometer R20 to 1,8 +/-- 0.6 V, see figure below.
Don’t touch potentiometer R32.

-- 9 --cga9d1ea
8. Fit the sensor so that there is the least possible angle between the longitudinal axis of the
sensor and the weld joint, in both the horizontal and vertical planes less then 35_.
(See the drawing on page 13 and 14)
9. When fitting the sensor, ensure that the front part of the sensor finger (secured by a uni-
versal joint) is pointing downwards towards the weld joint or towards the edge to be
sensed/tracked. This applies for all types of joints, including fillet welding when the
welding head is inclined. The sensor must not be radially misaligned by more than +/--
3_from this position in relation to the axes of the slide cross.
Any large deviation towards one side or the other puts the control performance at risk,
see page 13 and 14.
dga9b004
10. The equipment includes a fixing device for securing the sensor with a type D20 or D35
contact block. This allows course setting of the welding direction, height and angle round
the contact block. Important! The distance B between the steel clamp A and live parts
should be at least 5 mm.
11. Use the mini slide cross--head for exact adjustment of the position of the tip of the wire in
the welded joint. Adjust, too, the distance between the tip of the wire and tip of the guide
fingerifnecessary.
The mini--slide can be adjusted till no play exists by means of the stop screws on the
runner.
12. Check as follows that the sensor is operating correctly:
STurn the selector switch to
SUsing the joystick, run the vertical slide downwards towards a flat base until the tip
of the guide finger contacts the base. Continue to lower the slide until the red indi-
cating lamp goes out.
STake hold of the tip of the guide finger and push it to one side or the other. If the
equipment is working correctly, the horizontal slide motor should then start and
move in the same direction as the sensor tip is being pushed. If this does not
happen,change over the switch marked on the apparatus unit backplane.
13. As supplied, the tip of the sensor is straight, but can be bent by the user to suit a particu-
lar application or be replaced by some other type or shape of sensor,
see ”Extra Equipment for A6 GMD”.

-- 1 0 --
cga9d1ea
OPERATION
The joint tracking equipment is adjustable for different kinds of joint tracking, such as
tracking by sensing the edge and tracking by sensing the groove. The adjustment is made both
on the control box and on the sensor.
SJoint tracking by sensing the edge:
Set the selector switch on the control box to or depending on whether the de-
sired sensing direction is left or right. The two stop screws shall be screwed home, see
figure on page 7. This means that the sensor fingers are laterally spring--loaded and thus
permit edge sensing. Joint tracking by sensing the edge is used for fillet joints and similar
joints, see also table below.
SJoint tracking by sensing the groove:
Set the selector switch on the control box to or depending on whether vertical
and horizontal sensing is desired or vertical sensing only. The two stop screws shall be
screwed out at least two turns or to stop, see figure on page 7. This will disengage the
spring--load of the sensor fingers and permit groove sensing. If the stop screws are not
screwed out there is a risk that the sensor fingers start ”climbing” the joint walls of shal-
low V and U joints. See also joint table below for correct settings.
Examples of some different types of joints and of the guide finger angle against the
guiding edges.
Joint type Settings, control box
Double--flanged butt joint
I--weld
A=Guide bar
V--weld
1/2 V--weld
1/2 V--weld
U--weld