Characteristics Improvement; Optimal Adjustment Of Cycle Time - Mitsubishi Electric MELDAS MDS-R Series Technical Specification And Instruction Manual

9-3 Characteristics improvement

9-3-1 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 in areas near the maximum rotation speed, so
when adjusting, view 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 reciprocating cutting feed operation without 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
9. 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 speed, 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
HF44
HF74
HF53
HF103
HF153
HF203
HF353
Max. current value
350% or less
330% or less
380% or less
350% or less
380% or less
290% or less
250% or less
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