Mitsubishi MELDAS MDS-C1 Instruction Manual page 184

(4) Variable speed loop gain
If vibration occurs when the motor is rotating at a high speed, such during rapid traverse, or if
disturbing noise occurs, the state can be improved by lowering the speed loop gain during
high-speed rotation. The low-speed region speed loop gain used for cutting feed (G1 feed), etc., is
maintained at a high level, so the vibration can be improved without dropping the machining
accuracy.
No. Abbrev. Parameter name
SV005 VGN1 Speed loop gain 1
SV006 VGN2 Speed loop gain 2
Speed at the change
SV029 VCS
of speed loop gain
4. Servo Adjustment
Set the speed loop gain.
Set this according to the load inertia size.
The higher the setting value is, the more accurate the control will be,
however, vibration tends to occur.
If vibration occurs, adjust by lowering by 20 to 30%.
The value should be determined to be 70 to 80% of the value at the
time when the vibration stops.
If the noise is bothersome at high
speed during rapid traverse, etc, lower
the speed loop gain.
As in the right figure, set the speed
loop gain of the speed 1.2 times as
fast as the motor's rated speed, and
use this with SV029 (VCS).
When not using, set to "0".
If the noise is bothersome at high speed during rapid traverse, etc,
lower the speed loop gain.
Set the speed at which the speed loop gain changes, and use this with
SV006 (VGN2). (Refer to SV006.)
When not using, set to "0".
4 - 13
Explanation
VGN1
VGN2
0 VCS
(Rated speed × 1.2)
Setting range
1 to 999
-1000 to 1000
VLMT
0 to 9999
(r/min)