There is some dielectric material inside of workpiece, everything looks normal from outside, but suddenly, short circuit happens; It doesn’t work no matter whatever we try. It is likely some impurities in the workpiece while forging or stamping, these impurities is not conductive, and make short circuit happen, and break the wire finally. It is advised to use good quality material, or enlarge cooling liquid to flush impurities.
Normally, material processed by wire cut EDM had already been machined by grinding machine in advance, according to normal technology, material need to be demagnetized after grinding. If on demagnetization, metal chips of wire EDM cutting will absorb in the wall of gap, especially for large thickness cutting. Demagnetization will make cutting feed is not even, and worse surface quality, short circuit and wire broken.
For auto-centering of wire cut EDM, if surface of workpiece is not clean, and there is some oil, burr, dielectric material. When molybdenum wire feed to wall and haven’t started to discharge, but machine can’t change direction automatically, workpiece will bend wire and break it eventually. So it is advised to clean workpiece before cutting.
Recent Comments