Siemens SINUMERIK 840C - Manual (Page 716)

10 Axis and Spindle Installation 12.93
10.4.1 Drive optimization
Overshooting may also have one of the following causes:
• Acceleration too great (current threshold is reached)
• Excessive rise time of speed circuit
• Fault in speed controller (re-optimization may be necessary)
• Mechanical backlash
• Displaced location of mechanical components
• Load fluctuations (vertical axis)
For safety reasons, select a K
v
factor that is at least 10 % lower than the maximum possible
factor.
Important:
Axes that operate together with continuous path control must have the same K
V
factor.
K
V
factor check
Refer to the service display for the individual axes (see diagnosis description for selection) to
determine the size of the following error. The displayed value is the same with both positive
and negative traverse directions if the drift is compensated.
Subsequently check the input K
V
factor of all axes on traversing with reference to the following
error display.
Exact continuous path control requires that the dynamic behaviour of the axes is the same, i.e.
the same following error must occur at the same speed.
In the event of discrepancies, the differences must be compensated at the multgain or speed
actual value potentiometer.
10.4.1.4 Acceleration NC MD 276*
The specified accelerations
b x 10 -2 [m/s 2 ]
are used to accelerate and decelerate the axes.
This enables the axes to accelerate to the relevant speed and assume position quickly,
accurately and with the least possible wear and tear on the machine.
The customer must be questioned as to the machine's suitability for continuous decelera-
tion/acceleration. This value (if it does not overtax the drive) is entered in NC MD 276*.
This value normally lies in the range from 0.3 m/s 2 to 2 m/s 2 .
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SINUMERIK 840C (IA)