Mitsubishi MELDAS MDS-C1 Instruction Manual page 228

(3) Adjusting the variable current loop gain
In most cases, problems will not occur when the default value is used. This loop gain must be
adjusted if fine vibration occurs while the spindle motor is rotating at a high speed. Adjust the
current loop gain at the high-speed range, so that the output current to the spindle motor is stable.
•
If fine vibration occurs at high-speed range
•
When speed fluctuates (is unstable) at high-speed range : Increase SP069 in increments of
No. Abbr. Parameter name
Target value of variable
SP069 VIGN*
current loop gain
5. Spindle Adjustment
Details
Set the magnification of current loop gain (torque
component and excitation component) for a change
ending speed defined in SP068 (VIGWB).
When this parameter is set to "0", the magnification is 1.
SP069×(1/16)-fold
1-fold
SP067
SP017 (TSP)
SP067
Maximum
(VIGWA)
motor speed
0 to 6000 0
6001 to 8000 5000
8001 or more 5000
5 - 18
: Decrease SP069 in increments of
approx. 8
approx. 8
Setting range Standard
Speed
SP068 SP017
SP068 SP069
(VIGWB) (VIGN)
0 0
8000 45
10000 64
0 to 32767
0
(1/16-fold)