Characteristics Improvement; Optimal Adjustment Of Cycle Time - Mitsubishi MELDAS MDS-C1 Instruction Manual

4-3

Characteristics improvement

4-3-1

Optimal adjustment of cycle time

The following items must be adjusted to adjust the cycle time. Refer to the Instruction Manuals provided
with each CNC for the acceleration/deceleration pattern.
<1> Rapid traverse rate (rapid)
<2> Clamp speed (clamp)
<3> Acceleration/deceleration time : Set the time to reach the feedrate.
constant (G0t∗, G1t∗)
<4> In-position width (SV024)
<5> Position loop gain (SV003)
(1) Adjusting the rapid traverse
To adjust the rapid traverse, the CNC axis specification parameter rapid traverse rate (rapid) and
acceleration/deceleration time constant (G0t∗) are adjusted. The rapid traverse rate is set so that
the motor speed matches the machine specifications in the range below the maximum speed in the
motor specifications. For the acceleration/deceleration time constants, carry out rapid traverse
reciprocation operation, and set so that the maximum current command value at acceleration/
deceleration is within the range shown below. The output torque is limited at areas near the
maximum speed, so monitor the current FB waveform during acceleration/deceleration and adjust
so that the torque is within the specified range.
If the drive unit's input voltage is less than the rated voltage, the torque will easily become
insufficient, and excessive errors will occur easily during acceleration/deceleration.
(2) Adjusting the cutting feed
To adjust the cutting rate, the NC axis specification parameter clamp speed (clamp) and
acceleration/deceleration time constant (G1t∗) are adjusted. The in-position width at this time must
be set to the same value as actual cutting.
• Determining the clamp rate and adjusting the acceleration/deceleration time constant
(Features)
(Adjustment) Carry out cutting feed reciprocation operation with no dwell at the maximum
• Setting the step acceleration/deceleration and adjusting the clamp speed
(Features)
(Adjustment) Set 1 (step) for the acceleration/deceleration time constant and carry out cutting
Maximum current command value when adjusting acceleration/deceleration time constant
Max. current
Motor model
command value
HC52 Within 388%
HC102 Within 340%
HC152 Within 380%
HC202 Within 275%
HC352 Within 251%
HC452 Within 189%
HC702 Within 221%
HC902 Within 228%
HC53 Within 264%
HC103 Within 257%
HC153 Within 266%
HC203 Within 257%
HC353 Within 230%
HC453 Within 177%
HC703 Within 189%
(Note) The motor indicated with an asterisk indicates the combination with the S-type drive unit.
4. Servo Adjustment
: This will affect the maximum speed during positioning.
: This will affect the maximum speed during cutting.
: This will affect each block's movement command end time.
: This will affect each block's movement command settling time.
The maximum cutting rate (clamp speed) can be determined freely.
cutting rate and adjust the acceleration/deceleration time constant so that the
maximum current command value during acceleration/deceleration is within the
range shown below.
The acceleration/deceleration time constant is determined with the position loop
in the servo, so the acceleration/deceleration F∆T can be reduced.
feed reciprocation operation with no dwell. Adjust the cutting feed rate so that the
maximum current command value during acceleration/deceleration is within the
range shown below, and then set the value in the clamp speed.
Motor model
HA053N
HA13N
HA23N
HA33N
HA-LF11K2
HA-LF15K2
HC452*
HC702*
HC902*
HC353*
HC453*
HC703*
Max. current
command value
Within 240%
Within 240%
Within 230%
Within 230%
Within 215%
Within 240%
Within 242%
Within 248%
Within 228%
Within 242%
Within 248%
Within 228%
4 - 9
Max. current
Motor model
command value
HA40N Within 400%
HA80N Within 365%
HA100N Within 260%
HA200N Within 225%
HA300N Within 200%
HA700N Within 205%
HA900N Within 220%
HA43N Within 295%
HA83N Within 275%
HA103N Within 245%
HA203N Within 210%
HA303N Within 180%
HA703N Within 180%