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TE700 Instruction
Manual
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2.11 -
ADJUSTMENT STEPPER FUNCTION
The adjustment stepper function permits correcting the wear of the electrodes that affects the
quality of the welds. When the diameter of the electrodes increases, so does the contact
section between electrode and piece to be welded and consequently the welding current
density decreases (Amperes/mm
2
). If the same adjustment is maintained for the entire
electrodes' life, the quality of the last spots carried out is poorer as compared to the first ones.
In order to correct this event, the adjustment stepper function was introduced, also called
"stepper". The operating principle is to gradually increase the adjustment as the diameter of
the electrodes increases so that constant current density is maintained.
In order to describe the trend of the adjustment during the electrodes' lifespan, a stepper
curve is programmed. This curve is made up of one or more segments for each of which the
operator programs the number of welds and the relevant increment of the adjustment
parameter in percentage.
Once programmed, the increment of the adjustment parameter is applied to all the weld
programs that use the same tool number of the programmed stepper module.
Limits, if used, increase by the same percentage, as well as the pre-weld., post-weld. and
welding 2 adjustments and the energy value to be attained.
During the welding process, it is possible to correct the stepper curve trend by changing the
parameters determining its trend.
In order to begin a new stepper curve, reset the spot counter relevant to the stepper
module to be cleared, that is to say the one relevant to the tool in which the electrodes'
starting diameter was restored.
SIMPLIFIED USE OF THE STEPPER FUNCTION (LINEAR STEPPER)
The present example is carried out considering the control unit set to IK WORKING MODE.
Only tool 1 will be used and the only active stepper will be the one relevant to the parameter
adjustment associated with stepper law number 1.
The stepper function can be used in a simplified manner by programming a simple percent
increment for a specific number of welding spots that are to be carried out with the same
electrodes.
The operator must know the service life of the electrodes in order to adjust these parameters.
To do this run some welding tests with new electrodes before they are replaced. Under these
two conditions the currents, required for carrying out the welding spots of the required quality,
are assessed. The change in percent is calculated and then it is set in the control unit.
The parameters that allow the carrying out of the stepper function are entered in the
STEPPER MENU
. The instructions for programming these parameters are outlined in the
relevant paragraph.
In the "simplified" stepper function use, always set N.TOTAL STEPS parameter to 1 (since
there is only one segment to be programmed). Enter the number of welds to be carried out in
parameter SPOTS 1. In practice, the foreseen service life of the electrodes. Enter the
required percentage increase in parameter INCREMENT 1-L1.
