7
7.0
Optional Dancer Optimization
After tuning of the dancer, the following method will usually optimize the stability and responsiveness of
the dancer. The method begins by placing the dancer in PD mode with a roll diameter near core and
reducing the gain to a level which the user may consider unacceptable. Gain will subsequently be
increased to a more desirable level. If using PID mode, the dancer is placed in PID mode with a roll
diameter near full roll and the integrator is reduced to a level which the user may consider unacceptable.
Then, the integrator will be increased to a more desirable level. Sometimes, it may be necessary to first
make the PD mode adjustment at a larger roll diameter, and then refine the adjustment near core.
Do not switch between PD/ PID while the machine is running since this may result in a large transient
jump in the output.
1) With a roll diameter near core and the machine stopped, set the switch to
PD
mode.
2) Run the machine and adjust the
POS1
pot to center the dancer arm.
3) Decrease the
P
pot by rotating Counter Clockwise until the dancer stabilizes. The
POS1
pot may
require readjustment several times in order to keep the dancer roll centered.
DEFINITION: In the following steps the user will have to determine if the dancer is overshooting. To do
this, move the stable dancer away from its set position by pushing on the dancer, by bumping the
unwind/rewind roll, or by some similar means. If the dancer goes past the set position before settling to
the set position, it is overshooting. If the dancer goes straight to the stable position without going past it,
the dancer is not overshooting.
4) Increase the
P
pot by rotating Clockwise in small steps checking for dancer overshoot at each step.
Do this until overshoot is obtained.
5) Adjust the
D
pot in small steps checking for dancer overshoot at each step. Do this until the
overshoot is eliminated. The direction to adjust
D
for no overshoot is system dependent.
6) Repeat steps (4) and (5) until the overshoot cannot be eliminated using the
D
pot, or until the
P
pot is
full Clockwise.
7) Decrease the
P
pot by the amount necessary to eliminate the overshoot.
Adjustment is now complete for the dancer operating in PD mode. The next steps complete the tuning of
the dancer operating in PID mode.
8) With a roll diameter near full roll and the machine stopped, set the mode switch to
PID
.
9) Run the machine and adjust the pot to center the dancer roll.
10) Decrease the pot by rotating Counter Clockwise in small steps checking for dancer overshoot at
each step. Do this until overshoot is obtained.
11) Increase the pot by the amount necessary to eliminate the overshoot.
Adjustment is now complete for the dancer operating in PID mode.
POS2
I
I
