Mitsubishi Electric MDS-E Series Instruction Manual page 360

MDS-E/EH Series Instruction Manual
6 Spindle Adjustment
(2) Measuring the acceleration/deceleration waveforms
Measure the speed feedback and current feedback output by setting the monitor output data on "Time-series data
measurement" with NC Analyzer, and check if theoretical acceleration/deceleration time is within ±15%. Refer to
"NC Analyzer Instruction Manual (IB-1501086)" for details on setting the monitor output data.
Speed feedback
Current feedback
When acceleration/deceleration time does not match the theoretical value (an error rate 15% or more), check the
following items.
[1] There may be an error in calculating load inertia for the motor axis conversion used when calculating the
theoretical acceleration/deceleration time. Check the load inertia again.
[2] When acceleration time is long and deceleration time is short, friction torque is thought to be large. Check load
meter value at the maximum speed (spindle monitor screen). If the load is 10% or more, friction torque is
thought to be relatively large. Mechanical friction, such as bearing friction or timing belt friction, is assumed to
be large. Measure the acceleration/deceleration time again following trial run.
[3] Even if the problems above are not found, when acceleration/deceleration time does not match, there may be
a possibility of using spindle motor and spindle drive unit that are not specified, or using wrong parameters.
Check the spindle motor type and spindle drive unit type again, as well as the spindle parameter settings.
POINT
There are cases where acceleration/deceleration waveforms change depending on the spindle temperature.
Check the waveforms when the spindle temperature is high (after continuous operation) and when it is low.
CAUTION
Vibration or sudden acceleration/deceleration may occur during adjustment. When performing measurement with a
workpiece or tool installed, pay careful attention for the safety during adjustment.
Acceleration Deceleration
time:ta time:td
Acceleration/deceleration characteristics of spindle motor
329
Measure the time from current rise
to current fall.
IB-1501229-F