Avoiding vibration in slewing gear pieces

When machining long and slender workpieces which are often very sensitive to vibrations, the speed in critical areas should be set to a harmonic oscillation in a controlled manner during the machining process. The aim should be to change the spindle speed such that the machining process is not impaired and no chatter marks are formed on the rotating surface. To avoid this and to ensure a continuous working process, critical areas need to be overcome as quickly as possible. This application provides an option of how such a vibration occurring at the workpiece can be avoided.

The figure above shows an example of a workpiece, which is set to vibration by the unfavorable tension condition during the rotating process.

Change in speed of the master spindle can eliminate any vibrations

Permanent change in speed of the master spindle can eliminate any vibrations occurring in the slewing gear piece. When manually changing the spindle speed by using the override, it is very difficult to create a harmonious vibration speed of the master spindle. Therefore, a cycle which consists of two part subprograms (.SPF files) should be created. By selectively switching the cycle on and off, a harmonic vibration speed of the master spindle is forced. Both subprograms of the cycle form the basis for future use of the "OSZI" command, which can be safely used in the program GUIDE (G-code).

This application provides the following benefits:

• Avoiding chatter marks on the workpiece

• Precision turning process on the workpiece is still possible

The subprograms OSZI.SPF and OSZIOFF.SPF, which are used to turn the harmonic vibration at set speed on and off will be stored in the passwordprotected area of the system data / user cycles. This area is accessible only to authorized, qualified personnel. The end-user should be responsible, act deliberately and cautiously, as the cycles described require changes to system data.

Application