Stt wave shaping principles – Lincoln Electric IM649 Wave Designer User Manual

Page 63

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2. Find the Optimal Arc Characteristics

Use the following weld trials and adjustment sequence to tune the selected waveform for your
weld application at the designated workpoint (wire feed speed). Weld trials and adjustments are
more easily performed with one person welding while you adjust the waveform parameters at the
computer terminal.

a. Set the Invertec Trim control for a readout of 1.00. This will ensure that the wave shape is

designed at the midrange of the trim adjustment capability. The welding machine’s trim
control allows the welder to adjust the arc length between 0.5 to 1.5 (50% to 150%) times
the established arc length adjustment factor.

b. Maintain a constant stickout. The stickout should be equal to the expected average of the

welding application. We recommend about 5/8 in. to 3/4 in. (16 mm to 19 mm) electrical
stickout.

c. While welding a trial weld bead, adjust the waveform variables (peak current, background

current, tailout, etc.) to achieve a desired droplet transfer with a fixed 5/8 in. to 3/4 in.
(16 mm to 19 mm) stickout at the selected wire feed speed. Refer to paragraph B.5.

d. With the stickout at a fixed setting, make trail welds during each adjustment so you can

directly observe the effect of the adjustments in the arc and resulting weld. Adjust the
variables as needed to achieve the desired weld transfer at the fixed stickout.

NOTE: Wire feed speed controls the deposition rate. Peak current controls the arc length.

Background current controls the bead contour, and tailout adjusts power (heat) in the
arc. For optimum spatter control, the arc should be focused on the weld puddle.

Appendix B

B-9

STT WAVE SHAPING PRINCIPLES

WAVE DESIGNER

27850059

AMPERES

PINCH START

dV/dt CALCULATE

PEAK TIME

PEAK AMPS

TAILOUT
SPEED

BACKGROUND AMPS

TIME

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