Intuitive Graphical Interface Characterizes New EDM

Another phrase for “intuitive graphical interface” would be “easy-to-figure-out pictures shown on the control screen,” and that’s exactly what most distinguishes the new Roboform 350 family of ram (sinker) electrical discharge machines (EDMs) being introduced by GFAGIECHilles Technologies (Lincolnshire, Illinois). The new control system is being called DPControl, which stands for Dynamic Process Control. It is dedicated to “die-sinking” applications, especially moldmaking. The 350 machine itself also represents a substantial upgrading of the Roboform 35P platform, with new mechanical features not to be overlooked. However, the control is likely to dominate impressions of the new models.

The control is based on an integrated PC using the standard Microsoft Windows interface, so the format of taskbars, navigational tools, and icons will be familiar (and welcome) to most users. Essentially, the operator interacts with the control system by stepping through the various sequences of setting up and running a job. The operator chooses from an array of pictures that best matches what the operator wants the machine to do. The system queries the operator for essential information about the workpiece material, facts about the electrode, and desired outcomes (surface finish, dimensional tolerances, cavity depth and so on). Responses can be entered with the keyboard or selected with a finger tap on the touch screen.

Recommendations are made to guide the operator’s choices based on a built-in database. For example, once the operator has indicated the type of electrode and other key parameters about the job, the system automatically suggests the optimal undersizing of the electrode, the best number of electrodes to use for roughing and finishing, the most effective orbital pattern, and other details that constitute a complete, prioritized production strategy. From here, the system goes on to develop machining sequences and generator settings for each operation. Accepted strategies become part of a database that allows the user to replicate and modify the process model for similar jobs in the future.

Some of the most important benefits of this move to a Windows-based system are new capabilities and options for communication. An on-board Ethernet communications card simplifies linking with a shop network. This feature will also make it much simpler to integrate the machine into a cell where the EDM must interact with robotic devices and other automated equipment. (An optional OCRi.2 system is available for integrating a robotic electrode and workpiece magazine for stand-alone automation.) The control system can also be set up to send messages to pagers, cell phones or Web sites for remote monitoring and responses to alarm conditions.

Other productivity tools offered by the control system include graphic simulation of axis moves and sequencing, job interruption and job prioritizing. Simulation eliminates the need to conduct a dry run before machining. Job interruption allows a job in operation to be halted and moved aside to allow another job to be set up and completed. The original job can then be restarted and the system will know at what precise point to resume, with all settings and parameters restored automatically. Job prioritizing allows shop planners to organize pending jobs according to scheduling demands and the need to expedite.

Mechanically, the Roboform 350 features a short, oversized C-frame to minimize droop and deflection. Linear glass scales and a dual loop positioning system have been incorporated to enhance precision. Truly rapid axis moves for positioning will speed setup procedures. Developers have also boosted pulse and acceleration speeds in the Z axis for deep cavity work, noting that this advance has been accomplished with ballscrew technology. Automatic electrode changing takes 45 seconds compared to 65 on former models.

The Roboform 350 has a bigger brother, the Roboform 550, for heavier and larger workpieces.