HEIDENHAIN TNC 640 (34059x-01) - Manual (Page 434)

434 Programming: Turning Operations
13.3 Unbalance F
unctions
Unbalance is significantly influenced by the structural shape of the
workpiece (e.g. nonsymmetrical pump body) and by the chucking
equipment. As these factors frequently cannot be changed, you
should compensate any existing unbalance by means of balancing
weights. The TNC provides the "Measure Unbalance" cycle for this
purpose. The cycle determines the existing unbalance and calculates
the mass and position of the required balancing weight.
The rotation of the workpiece creates centrifugal forces
that can cause vibration (resonance), depending on the
unbalance. This vibration has a negative effect on the
machining process and reduces the tool life. High
centrifugal forces can damage the machine or push the
workpiece out of the fixture.
Check the unbalance whenever you clamp a new
workpiece. If required, use balancing weights to
compensate any unbalance.
The removal of material during machining will change the
mass distribution within the workpiece. This may also have
an influence on workpiece unbalance. Therefore,
unbalance checks should also be carried out between
machining steps.
Keep in mind the mass and unbalance of the workpiece
when choosing the speed. Do not use high speeds with
heavy workpieces or high unbalance loads.