Conventional EDM is commonly known as Spark EDM. This process is often used when the desired cut or design feature does not penetrate through the entire workpiece. Electrodes for Spark EDM are mostly manufactured from graphite or copper tungsten. RAM EDM electrodes utilize a negative-formed shape which contains all the detail of the final workpiece. Through CNC programming, the electrode is moved along the workpiece, never contacting the piece but creating an area between the electrode and workpiece referred to as Spark Gap. As the electrode moves along the x, y, c and z axes, complex indentations, shapes, vents and cavities are created. The intricacy that can be achieved with conventional EDM is unmatched by any other method of machining.
Typically RAM EDM applications are performed with the workpiece fully submerged in solution bath. This fluid serves various purposes including flushing away of the eroded material, cooling the heat affected zone and preventing damage to the workpiece, and acting as a conductor between the electrode and the workpiece. Spark EDM has become a standard method for machining production prototypes due to the precision and abstract cuts allowed by EDM that are not available through alternative machining systems.
HDT electrodes are created through a 4-axis high speed milling process. Our electrodes are milled to completion and incorporate all features of the final product with no hand-scraping required.
Small hole drilling EDM machining allows a 0.3mm-6.1mm diameter hole to be drilled through a 100mm piece of soft or hardened steel in about 10 seconds with an average wear rate of 50% to 80%. This process uses a long brass or copper electrode in the form of a tube. The electrode is held in a chuck and rotated as a flow of distilled water flows through the electrode and flushes away the eroded material.
Though small hole drilling EDM was initially used mainly for pre-drilling holes for wire EDM, its uses have since become more widely recognized. Mold and part manufacturing-injection nozzles, oil drain holes, hydraulic cylinders and dowel pins, as well as turbine blades, ball bearings and safety wire holes in hex nuts are just some of the manufacturing areas that benefit from the use of small hole drill EDM.
HDT has found that small hole drill EDM also has a place in venting, small ID work as well as workpieces with small diameters.