Universal Laser Systems ULS-25PS, Operation Manual

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will highlight the color and allow changing of the settings by using the scroll bars or
highlighting out and typing in each setting. It is possible to set one color at a time or
click on additional colors to set more than one at a time.
Power Setting
Laser power is controlled by assigning the percentage of power from 0 - 100% to each
color used in the graphic drawing. Since the laser is proportionally pulsed, this
percentage represents how long the laser remains on for each laser pulse fired.
Basically, the power setting is directly related to how deep the engraving will be.
Speed Setting
This setting controls how fast the motion system moves in a percentage of the
maximum speed of the system. For example, 100% Speed is equivalent to 25 inches
per second straight line velocity. Therefore, 10% Speed is equal to 2.5 inches per
second. When engraving, this is the rate in which the motion system moves back and
forth. When cutting, this is the speed of the straight lines. If cutting curves or circles,
the motion system automatically slows down. For example, there is no speed
difference when cutting a circle at 50% or 100% Speed because curves will run slower
than straight lines even if it is set to 100%. Proportional pulsing of the laser will ensure
that there is no difference in the depth of cut from straight lines to curves. Power and
speed work together in determining how deep the engraving will be. Higher power
settings and slower speeds will produce deeper engraving.
PPI
PPI stands for laser pulses per inch. This setting determines how many laser pulses,
per linear inch, the laser system will fire. Again, since the laser system is
proportionally pulsed, all pulses will fire equally spaced from one to the next regardless
of changes in Speed, Power, acceleration, deceleration, or the cutting of curves. For
example, when setting the PPI to 500 and using a standard lens that has a laser spot
size of seven thousandths of an inch, significant pulse overlap will occur. The laser
system fires a laser pulse and moves over two thousandths of an inch (that is 1 inch
divided by 500). It then fires the next pulse and so on, overlapping the pulses
significantly. Lines are formed by pulsing the laser pulses so close together and slightly
overlapping each other that it appears to be a continuous line. Dot matrix printers work
the same way except the laser system uses laser pulses instead of ink dots. When
engraving, it is advisable to use a PPI setting of 500 or higher. If using less, the image
resolution of the engraving is reduced. For cutting, a PPI of 150 and above can be
used. Using less than 150 will result in the pulses being spread so far apart that they
will not touch one another. This is a good example on how to perforate paper.
Increasing or decreasing the PPI setting has absolutely no effect on engraving speed.
The laser must either fire more quickly or slowly. Experiment with using different PPI
settings on some scrap material when cutting or engraving and note the results.
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