Manfred Weber
Metra Mess- und Frequenztechnik in Radebeul e.K.
PC Vibration Measurement System VibroMetra

Rotor data

These settings are important for specifying the rotor properties.
Rotor data

Number of planes

1. Number of planes
Factors for the decision between one or two plane balancing:
  • One-plane balancing saves time compared with two-plane balancing.
  • Two-plane balancing requires at least one additional balancing run and mass shifting in both planes.
  • One-plane balancing only compensates static unbalance.
  • Two-plane balancing compensates static and couple unbalances.
  • Disk shaped rotors can be usually balanced in one plane.
  • For longish rotors two-plane balancing is required in many cases.

Balancing radius

2. Balancing radius
This is the radius at the rotor where mass shifting will be done. It is not necessarily the outer rotor radius.
Simple balancing with the aim of reducing the unbalance mass with the methods of  adding or removing mass will also succeed without entering a balancing radius. For many other calculations, however, the balancing radius is needed. Therefore entering a radius is recommended.

Use complete circumference

3. Use complete circumference
This selection allows balancing at any angle position of the rotor circumference.

Use fixed positions

4. Use fixed positions
If the rotor only allows changes at a limited number of positions, e.g. when balancing propellers or crankshafts, choose this option.

Number of fixed positions

5. Number of fixed positions
You can enter here between 3 and 360 positions. VM-BAL assumes that the fixed positions are evenly distributed in the same angles at the rotor circumference.

Start angle

6. Start angle
For efficient balancing the zero angle should correspond to the angle of the rotation speed mark at the rotor. This will not always be the case when balancing at fixed positions, e.g. in two-plane balancing when there is an offset between the fixed positions of both planes. You may enter here an angle offset.

Additional data

7. Additional data
If rotor mass and rotation speed are known, it is recommended to enter them here. This data is not mandatory for balancing but it helps to determine the right test mass and to calculate balancing quality to ISO 1940.
Disable the checkboxes if the data is unknown.