Similar to multitask machining in the macro world, doing all micromachining operations in one machine enhances part precision and improves production efficiency. New to North America, the standard Model DT-110 Hybrid µEDM from Mikrotools Pte. Ltd. performs sinker EDMing, EDM milling, electrical-discharge grinding (EDGing), turning, milling, drilling and part inspection. Options include attachments for wire EDMing and wire EDGing. According to Mervyn Fathianathan, CEO of Mikrotools, every machine purchased so far has included the optional attachments.

Mikrotools' Model DT-110 Hybrid µEDM (above) can perform seven machining operations. Below: Users can directly turn electrodes, such as this 19µm-dia. shaft, on the machine with PCD tools.

Because the machine has a turning capability, users can produce microelectrodes on the same machine in which they are applied. Fathianathan explained that the patented microturning process reduces the time needed to produce an electrode from hours to minutes.

In addition, turning electrodes on the machine prevents setup errors that can occur when an electrode is fabricated on another machine, according to Fathianathan. "With microturning in place, we can automatically fabricate electrodes, perform the EDM operation and refabricate the electrode without human intervention," he said.

Fathianathan said the company developed the enhanced microturning technology specifically for on-machine electrode fabrication. "For example, it is very difficult to achieve straight shafts below 70µm in diameter. In many cases, the electrode will either break or start to wobble due to excessive radial cutting forces on the microshaft."

In addition, Mikrotools developed a process to fabricate ultrasharp PCD tools, via microEDMing, on the machine. "With the ultrasharp tool, we have microturned shafts to less than 20µm," Fathianathan said.

Although Mikrotools offers an optional 60,000-rpm spindle and users tend to prefer it for running tools with tiny diameters, Fathianathan noted the standard 3,000-rpm spindle can be more effective. This is because the chip load on a microtool's cutting edge is small when high-speed machining, so the tool ploughs the material instead of cutting it, which imparts a poor surface finish. "Moreover, at high speeds, vibration is very high and that further aggravates the surface finish," he said. "On the contrary, if the spindle speed is low, chip loading on the cutting edge is reasonable, the vibration level is low and the surface finish is good."

Mikrotools announced that Global Specialty Machines LLC will distribute the Model DT-110 Hybrid µEDM in the U.S. and Canada. Average lead time for acquiring the machine in North America is 8 to 10 weeks, according to Charles Quillen, executive vice president of Global Specialty Machines. He added that the base machine will sell for about $75,000 less than microEDMs from competing builders.

For more information about Singa-pore-based Mikrotools Pte. Ltd., call +65-6776-9013 or visit www.mi krotools.com. For more information about Global Specialty Machines LLC, Mason, Ohio, call (513) 701-0441 or visit www.globalsmsas.com. CTE