HEIDENHAIN iTNC 530 Service Manual page 69

There are peaks in the Pos.Diff. signal when the direction is changed during braking and
acceleration. Between the rotary encoder in the motor and the scanning head at the table there
are coupling systems (belts, gears, couplings) and the mechanics (recirculating ball nut,
guideways, etc.)
The machine at which the recording was made features a belt drive.
It can also be seen that the Pos.Diff signal increases and decreases depending on the traverse
direction. This behavior is due to an inaccuracy in the transmission ratio of the drive (e.g. belt,
ball screw).
Ideally, you have older recordings of the machine which you can now compare with the new
Conclusion
ones.
If the position difference has increased, in most cases rectifications of the mechanics or the
coupling system are required.
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