N1500i FACS Manual
35
Part No. 729-110-053 V.1.03
© 2018 Nelson Stud Welding, Inc. All rights reserved.
3.6 Drop Time Variables
This section describes several different conditions that affect drop time.
This time duration will vary under many different conditions as outlined
in the text below.
Power Source Gun Control and Trigger Switch Circuit:
The rate in which the gun coil energy is removed plays a large part in
how fast the stud will drop. If the coil
only
has an anti-parallel diode (in
either the gun itself or inside the power source), it will drop much later
than a configuration with a diode/resistor since the energy is dissipated
in the resistor after the coil is de-energized.
Plunge Dampener:
Tranquil Arc plunge dampeners are meant to slow the rate of stud travel
speed (in the downward direction). Dampeners can adjust this rate for
up to a few hundred milliseconds of travel time.
Temperature:
As temperatures rise, dampeners have less of an impact. They allow
the stud to fall nearly 65% faster at 90 degrees F than at 0 degrees F.
Molten Stud Shape:
As the stud melts during the weld, it has the potential to change shape.
It may elongate or even drip. The molten shape of the stud will vary as
the weld heat varies. These factors can change the timing of the weld
short circuit.
Troubleshooting Inconsistent Drop Times
1.
Eliminate excessive lift. Too much lift increases the possibility of
stud ‘hang up’.
2.
Be sure the weld energy is appropriate for the application.
3.
Inspect foot alignment
– Adjust if necessary. A misaligned foot
will almost guarantee stud ‘hang-up’. Make sure the stud is
centered in the ferrule.
4.
Inspect chuck
– Replace if necessary. Check for a good grip of
the stud in the chuck. A good grip is needed to eliminate stud
slippage.
5.
Tighten foot-retaining screws. These screws hold the foot in place
during a weld while pressure is placed on the foot. Slippage of
the foot will lead to a faster drop time.
6.
Inspect and clean gun housing and related parts
– replace
parts as needed. Debris in this housing will resist travel.
