Rockwell Automation Motion Analyzer Software - Manual (Page 98)

98 Rockwell Automation Publication MOTION-UM004B-EN-P - October 2012
Chapter 2 Sizing Your System
Table 57 - Press Roll Feed Parameters
Parameter Description
Load
(label 1 in
Figure 78 or
Figure 79 )
Moving Material Mass The mass of the material in the loop and on the flat before the Nip/Feed rolls.
(3)
Bias Force The force required to overcome the force of gravity on the loop.
(3)
Drive Roll Diameter The diameter of the roll in direct contact with the strip, driven from the motor.
Total Roll Inertia
(2)
The total inertia of the strip material at the drive shaft.
Cut (Waiting) Time
The time during which the material must be stationary in an accurate position. This value is only required for Press Roll Feed -
Constant Time applications (refer to the red boxes in images above).
Cut (Waiting) Angle
The crank angle during which the material must be stationary in an accurate position. This value is only required for Press Roll
Feed - Constant Angle applications (refer to the red boxes in images above).
Critical Preferences
(1)
(label 2 in Figure 78 or
Figure 79 )
Max Average Line Speed
Select this option for data entry when the maximum design speed of the constant-speed sections of the line is known. This
speed does not refer to the peak velocity of the feeder section, which is determined by Motion Analyzer software.
Min. Cut length at
Max line speed
When you select the option to enter data based on Max Average Line Speed, this data is required. This is
the critical condition on which the sizing process is performed. To cut shorter lengths than this critical
length, the line speed must be reduced.
Cuts/min
Select this option for data entry when the number of cuts made by the system per minute is known.
Max. Cut length at
Cuts/min
When you select the option to enter data based on Cuts/min, this data is required. This is the critical
condition on which the sizing process is performed. To cut longer lengths than this critical length, the
line speed must be reduced.
System Properties
(label 3 in
Figure 78 or
Figure 79 )
Settling Time
This is the time required for the system to achieve the required position accuracy before the cut commences. The finer the
required accuracy, the longer the settling time value. This time is typically 20 to 75 ms for an A servo system.
Cosine Compensation
This option is only required for Press Cutter Knife Drive applications. The Cosine Compensation is used to make sure that while
the press cutter knife is in contact with the material being cut, the horizontal component of the knife’s velocity matches the
material speed.
Motion Type Properties
(label 4 in
Figure 78 or
Figure 79 )
Linear Select this option for standard linear acceleration and deceleration ramps.
S-Curve
Select this option for ‘S’ shaped acceleration and deceleration ramps that are used to produce smoother motion. You need to
enter the percent jerk value for this option.
Triangular Move
Select this option for a triangular load profile. This option is only required for Press Roll Feed - Constant Angle applications (see
red box in
Figure 79 ).
(1) At very long cut lengths, the limiting factor, determined by the design speed of the leveler rolls and unwinder, is the maximum line speed. As cut length is reduced, the servo has to index more and more
rapidly until the peak or RMS (root mean squared) torque limit is reached. To cut shorter lengths than this critical length, the line speed must be reduced. Sizing is based on this critical length, maximum
line speed and cut time, which are typically specified.
(2) Use the Inertia Calculator Template on page 105 to calculate the inertia value for your application, if the value is not readily available.
(3) You can enter this data manually or use the Loop Calculator on page 99 , to determine the value.