Today, more than ever, a machine shop must possess the flexibility to quickly respond to the changing needs of its customers. Leadtimes are shortening, lot sizes are shrinking and the supply of skilled shopfloor workers is depleting. Recognizing these trends, machine builders are developing equipment that will improve a shop’s customer-response time and allow inexperienced workers to effectively operate new-technology equipment.
An example of this is the Agietron Spirit ram EDM from Agie (Lincolnshire, Illinois). This compact machine was designed with a number of EDM “reduction” trends in mind—reduced floorspace requirements, rate of electrode wear and operation learning curve. The Spirit is said to be ready for operation in less than 1 hour, after leveling, connection of electrical and air lines, and filling with dielectric fluid. The machine and control/power supply unit fit within a 6-square-foot work area.
According to Don McMillan, applied technology manager for Agie, the Spirit “targets tool and die and production environments in which more than one person will operate the machine, or there isn’t a dedicated EDM operator.” To perform effectively in these situations, a machine must be easy to operate. The Spirit’s Windows XT-based control has an icon-driven interface that simplifies complex job programming for multi-cavity, planetary, helical-shape, deep-rib and four-axis erosion. This is especially helpful for inexperienced EDM operators.
Mr. McMillan points out that because electrode production is the most costly component of ram EDM, reducing the rate of electrode wear is important. “To help overall burn speeds, many EDM manufacturers focus on improving the machine’s Z-axis jump speeds to help better flush the burn area with dielectric oil. Agie also works to quicken system servo response, which is the time in milliseconds that the machine senses the relative position of the workpiece to the electrode so that the two do not contact each other during erosion.” A fast response time enables the machine to be more sensitive to changing burn gap conditions, which reduces the risk that the electrode will abrade against the workpiece and wear too quickly. Accurate power supply components and fiber-optic feedback to the servo system are said to assist in speeding the response time.
The Spirit’s four-electrode tool magazine is compatible with many common toolholder styles, allowing unattended production and more efficient use of labor. In addition to production work, the Spirit can perform simple repairs and rework when used in its manual positioning and erosion mode. An operator can jog the electrode into position within the damaged cavity to perform repair jobs that might normally be performed on a dedicated manual machine.