| Directions: |
|
Enter a master speed command in percent, as
whole numbers. Maximum speed is 100%.
Click "Master Line Speed" to
enter the command.
Enter
cut length, between 1 and 100 as
whole numbers.
Click "Enter Cut Length" to store your entry.
|
| System
Basics |
|
This
system uses two digital speed controls for a cut-to-length process. A
continuous process such as extruding pipe is an example. Using the above
design, the follower drive will synchronize its speed with the master drive
for enough time for a cut to be performed. After the cut operation, the
follower rapidly moves back to be in position to make the next cut. Speed command outputs to each drive or entered via a keypad,
and the usual parameters of speed signal level, and scaling can be displayed. Speed sensing feedback from each motor (or
driven machine shaft) provides position references. The key feature in
this system is the ability to parallel connect the master speed feedback to
the follower control as an "auxiliary" feedback. Digital outputs can
be used to clamp and unclamp, or simply start and stop a saw, drill, ink
printer, etc.
|
| Benefits
of this system |
-
Drives
can be mixed ie DC, eddy current or AC.
-
Entering
the cut length is easy and flexible.
-
The
follower cut speed is automatically adjusted when the master line speed is
set.
-
Very
flexible. Can be used to paint parts, drill holes, cut off operations,
fill containers, etc.
|
| Drawbacks
and Pitfalls of this system |
-
Product
slippage or misalignment is not accommodated in this design.
-
Scaling
of each drive speed can require running product for a considerable time.
-
The
programming of the controllers on startup can be complicated.
-
Troubleshooting
speed control of each drive can be difficult.
-
Dwell,
advace and retard functions can take time to set up. (Not shown in demo).
|
| Basic
Bill of Materials for the system shown (excluding power transmission, etc.) |
|
|