Rockwell Automation 1771-QDC, D17716.5.93(Passport) PLASTIC MOLDING MODULE - Manual (Page 254)

Tune Your Machine
Chapter 10
10-26
Important: Fast segment velocities or high segment pressures may cause
the clamp to overshoot the start low pressure close or start open-slow
position. If you increase a velocity or pressure setpoint in a fast clamp
close (or open) movement, we recommend that you increase the distance to
the start LPC position (or decrease the distance to the open-slow position)
at least temporarily to assure a successful low pressure close (or open
slow) movement and mold closure (or opening).
Important: Avoid using the same velocity or pressure setpoint on
sequential segments. For better control, use a single segment of longer
length or duration (figure 10.3).
Figure 10.3
Better Control from Fewer and Longer Steps
Clamp Close Profiles
Rather than using a profile with
multiple steps at the same
velocity or pressure...
Use fewer, longer steps
Start Clamp LPC Position Setpoint (CPC61)
The QDC module uses this clamp position as protection against running a
clamp close profile into the mold protection zone. Although you can use it
as an operational setpoint when CPC03-B11 = 0 (see discussion of
End-of-Segment Position Setpoints above), its purpose is to guard against
mold damage resulting from profile entry errors.
Important: This position setpoint should be determined and set only by
qualified personnel, so we do not present it on any Pro-Set 600 screen.
Calculate CPC61 by determining the smallest distance required for the
QDC module to safely assume pressure control:
prior to mating the two mold halves
with the clamp closing at maximum velocity and pressure