Preface
This machine was a running machine, but the older controls were very unreliable. The old CNC logic was traced to an indexing problem that looked like spacing error, but in fact was caused by the operational sequence of the older software. Upgrading to the newer Siemens 840D has completely corrected this issue.
Original Condition
This machine was fully recontrolled in its current location in the Eastern United States. It was a running machine, so there was little mechanical work required to complete the recontrol. However the customer requested that we replace the axial and radial ballscrews, plus the thrust bearing sets in the process of the recontrol. These two axes sustain a high number of repetitious motions during every cycle, and the replacement of the screws was an inexpensive and fiscally wise decision to increase the longevity of the machine and reduce future down time.
The Recontrol Process
As part of the recontrol project Machine Tool Builders designed and manufactured a completely new electrical cabinet and operator’s station. Since there were no complaints about the grinding spindle, we reused the original Kapp spindle motor, but replaced the drive with a new Siemens 611D unit. We replaced both the axial and radial scales with new Heidenhain absolute scales. We installed all new servo motors and new motor power and feedback cables. We engineered and manufactured the mechanical adaptations required to convert the machine from the old analog Bosch servo system into a fully digital servo control system.
The new control system was centered on a Siemens 840D CNC and a PCU 50 front end with Windows XP Pro and the drives were all changed to new Siemens 611D servos. This combination of controls was extremely cost efficient, offered short lead times and was very easy to implement, which translated into savings for the customer.
The Conversational Software
We installed our newest version of MTB GearCAM software which allows for very easy Windows based programming for the gear, wheel and process information. The software is structured around a database concept, where you can store multiple gears, wheel and processes files. Then at the click of a mouse, you can select any combination of gears, wheels and processes to be recalled and executed. Storage and retrieval of the completed programs is made easy due to the Windows XP environment and the PCU 50’s onboard hard drive.
