Cycle 892 CHECK UNBALANCE

ISO programming

G892

Application

 
Machine

Refer to your machine manual.

This function must be enabled and adapted by the machine manufacturer.

Unwucht

An unbalance can occur when turning an unsymmetrical workpiece, such as a pump body. This may cause a high load on the machine, depending on the rotational speed, mass and shape of the workpiece. With Cycle 892 CHECK UNBALANCE, the control checks the unbalance of the turning spindle. This cycle uses two parameters. Q450 describes the maximum unbalance and Q451 the maximum spindle speed. If the maximum unbalance is exceeded, an error message is displayed and the NC program is aborted. If the maximum unbalance is not exceeded, the control executes the NC program without interruption. This function protects the machine mechanics. It enables you to take action if an excessive unbalance is detected.

Notes

 
Machine

Your machine manufacturer configures Cycle 892.

Your machine manufacturer defines the function of Cycle 892.

The turning spindle rotates during the unbalance check.

This function can also be run on machines with more than one turning spindle. Contact the machine manufacturer for further information.

You need to check the applicability of the control's internal unbalance functionality for each of your machine types. If the unbalance amplitude of the turning spindle has very little effect on the adjoining axes, it might not be possible to calculate useful unbalance values from the determined results. In this case, you will have to use a system with external sensors for unbalance monitoring.

 
Notice
Danger of collision!
Check the unbalance whenever you clamp a new workpiece. If required, use balancing weights to compensate any imbalance. If high unbalance loads are not compensated for, then this may lead to defects on the machine.
  1. Before starting a new machining cycle, run Cycle 892.
  2. If required, use balancing weights to compensate for any unbalance.
 
Notice
Danger of collision!
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. If high unbalance loads are not compensated, then this may lead to defects on the machine
  1. Make sure to also run Cycle 892 between the machining steps.
  2. If required, use balancing weights to compensate for any unbalance.
 
Notice
Danger of collision!
High unbalance loads, especially in combination with a high mass, may damage the machine. Consider the mass and unbalance of the workpiece when choosing the speed.
  1. Do not program high speeds with heavy workpieces or high unbalance loads.
  • This cycle can only be executed in the FUNCTION MODE TURN machining mode.
  • If Cycle 892 CHECK UNBALANCE has aborted the NC program, then we recommend that you use the manual MEASURE UNBALANCE cycle. With this cycle, the control determines the unbalance and calculates the mass and position of a balancing weight.
  • Unbalance in turning operations

Cycle parameters

Help graphic

Parameter

892_2

Q450 Max. permissible runout?

Specifies the maximum runout of a sinusoidal unbalance signal in millimeters (mm). The signal results from the following error of the measuring axis and from the spindle revolutions.

Input: 0...99999.9999

Q451 Rotational speed?

Enter the rotational speed in revolutions per minute. The test for an unbalance begins with a low initial speed (e.g., 50 rpm). It is then automatically increased by specified increments (e.g., 25 rpm). until the maximum speed defined in parameter Q451 is reached. Spindle speed override is disabled.

Input: 0...99999

NC programs contained in this User's Manual are suggestions for solutions. The NC programs or individual NC blocks must be adapted before being used on a machine.

  • Change the following contents as needed:
  • Tools
  • Cutting parameters
  • Feed rates
  • Clearance height or safe position
  • Machine-specific positions, e.g. with M91
  • Paths of program calls

Some NC programs depend on the machine kinematics. Adapt these NC programs to your machine kinematics before the first test run.

In addition, test the NC programs using the simulation before the actual program run.

 
Tip

With a program test you determine whether the NC program can be used with the available software options, the active machine kinematics and the current machine configuration.

Example

11 CYCL DEF 892 CHECK UNBALANCE ~

Q450=+0

;MAXIMUM RUNOUT ~

Q451=+50

;SPEED