Turn to Tungsten
EDMing is typically a slow process, and that holds true when it is used for microdrilling. cnc milling machine “It’s very slow, and the finer the details, the slower it is,” said , president and owner of Optimation Inc. The Midvale, Utah, company builds Profile 24 Piezo EDMs for micromachining and also performs microEDMing on a contract-machining basis.
Optimation produces tungsten electrodes using a reverse-polarity process and machines and ring-laps them to as small as 10μm in diameter with 0.000020" roundness. cnc milling machine Applying a 10μm-dia. electrode produces a hole about 10.5μm to 11μm in diameter, and blind-holes are possible with the company’s EDM. The workpiece thickness for the smallest holes is up to 0.002", and the thickness can be up to 0.04" for 50μm holes.
After working with lasers and then with a former EDM builder to find a better way to produce precise microholes, Jorgensen decided the best approach was DIY. “We literally started with a clean sheet of paper and did all the electronics, all the software and the whole machine from scratch,” he said. Including the software, the machine costs in the neighborhood of $180,000 to $200,000.
Much of the company’s contract work, which is provided at a shop rate of $100 per hour, involves microEDMing exotic metals, such as gold and platinum for X-ray apertures, stainless steel for optical applications and tantalum and tungsten for the electron-beam industry. cnc milling machine Jorgensen said the process is also appropriate for EDMing partially electrically conductive materials, such as PCD. “The customer normally doesn’t care too much about the cost,” he said. “We’ve done parts where there’s $20,000 [in time and material] involved, and you can put the whole job underneath a fingernail. We do everything under a microscope.”