Preface
This machine started out life as a mechanical Michigan Gear Grinder. At some point in time, Carl Hoglund had converted the machine to a quasi CNC machine using stepper control on all the axes, and a PC to run the machine. Due to the machines often unreliable and inflexible operation scheme, MTB was asked to recontrol the machine using our latest generation of gear grinding software.
Original Condition
This machine was fully recontrolled in its current location in the western United States. It was a running machine, so there was little mechanical work required to complete the recontrol. However due the dressers repeatability issues we exchanged the original Hoglund dresser system with a new Normac two axis dresser.
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 was no complaints about the grinding spindle, we reused the Precise spindle motor and drive for economy reasons. We replaced both the axial and radial scales with new Heidenhain absolute scales. We installed a new Heidenhain absolute angular encoder on the work head to measure the index angle. 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 stepper 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.