EFD Ultra 325TT User Manual page 74

Ultra TT User's Guide
®
Version 1.2
A NORDSON COMPANY
Backtrack Length
This is the horizontal distance the dispensing head moves back over
the dispensed line after raising up the Backtrack Gap distance. This
encourages congealed fluids to detach and distributes any excess
fluid back across the line.
The units are in inches or millimeters. Typically, 30 - 40 mils (0.030 -
0.040 in) is sufficient.
Backtrack length can be negative. This will force the movement of
the tip to move forward in the same direction as the line, instead of
backwards over the line. This can useful when dispensing a closed path, such as a square or
circle.
Backtrack Speed
This is the speed the dispensing head travels at when moving along the Backtrack Length. The
units are either in inches/second or mm/second. Typically, 2 in/sec or 50.8mm/sec is sufficient.
Retract Speed
This is the speed of the dispensing head while moving the Retract Distance. The units are in either
inches/second or mm/second. Typically, 2 in/sec or 50.8mm/sec is sufficient.
Retract Distance
This is a vertical distance that the dispensing head moves after the Backtrack Gap and Backtrack
Length dispensing commands are completed. The figure below shows the relationship between
Retract Distance, Backtrack Gap and Backtrack Length.
The Retract Distance must be set high enough so the machine can move safely to the next point
without hitting any obstruction on the work piece.
The units are in either inches or millimeters. Typically, 30 mils (0.030 in or 0.762mm) is sufficient.
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