Unbalance compensation in turning operations
Application
In a turning operation, the tool is in a fixed position, whereas the rotary table and the clamped workpiece rotate. Depending on the size of the workpiece, the mass that is set in rotation can be very large. As the workpiece rotates, it creates an outward centrifugal force.
The control offers functions to detect the unbalance and support you in compensating for it.
Related topics
- Determining the unbalance of the current fixture
- Cycle 892 CHECK UNBALANCE
- Cycle 239 ASCERTAIN THE LOAD (option 143)
Description of function
Refer to your machine manual.
Unbalance functions are not required and available on all machine tool types.
The centrifugal force that occurs basically depends on the rotational speed, the mass and the unbalance of the workpiece. A body with an uneven mass distribution that is put into rotary motion produces an unbalance. If the mass object is rotating, this creates outward-acting centrifugal forces. If the rotating mass is evenly distributed, the centrifugal forces cancel each other out. You compensate for the arising centrifugal forces by attaching compensation weights.
The control provides the MEASURE UNBALANCE cycle for this purpose. The cycle determines the existing unbalance and calculates the mass and position of the required balancing mass.
Measure unbalance (#50 / #4-03-1)
With Cycle 892 CHECK UNBALANCE you define the maximum permissible unbalance and the maximum shaft speed. The control monitors these entries.
Cycle 892 CHECK UNBALANCE (#50 / #4-03-1)
Unbalance monitor
The Unbalance Monitor function monitors the unbalance of a workpiece in turning mode. If a maximum unbalance limit specified by the machine manufacturer is exceeded, the control issues an error message and initiates an emergency stop.
The control automatically activates the Unbalance Monitor function when you switch to turning mode. The unbalance monitor is active until you switch back to milling mode.
Notes
- Clamp the workpiece in the spindle center
- Clamp workpiece securely
- Program low spindle speeds (increase as required)
- Limit the spindle speed (increase as required)
- Eliminate unbalance (calibrate)
- The rotation of the workpiece creates centrifugal forces that lead to vibration (resonance), depending on the unbalance. This vibration has a negative effect on the machining process and reduces the tool life.
- The removal of material during machining will change the mass distribution within the workpiece. This generates the unbalance, which is why an unbalance test is recommended even between the machining steps.