b'Wired for SuccessTurn out the lights on wire EDMing.By Kip HansonO f all machining processes, wire EDMing is perhaps best suited for lights-out manufacturing. No chips get in the way. There are no worries about cutting tool wear or breakage. And if a wire breaks or shorts out, the machine tries to rectify the problem before notifying a human that it needs help. This allows tool and die makers and an increasing number of tra-ditional machine shopsespecially those serving the aerospace and medical industries, where wire EDMing is used to cut oth-erwise unmachinable part featuresto significantly boost avail-able machine time while reducing labor costs.Tap, TapUnfortunately, the one thing that can go wrong might actu-ally break the machine tool. When a slug comes loose, it can fall into the lower nozzle and cause damage or become jammed between the head and workpiece. One inelegant solution is so-called slugless EDMing, in which the wire vaporizes the slug, but this eats up huge amounts of time, wire and electricity. Small metal tabs can be left to support the slug until the next morning, but removing them requires additional processing and human intervention.Steve Raucci, EDM product manager at Methods Machine Tools Inc., Sudbury, Massachusetts, offers a solution. He said the Core Stitch function on FANUC RoboCut -CiB series wire EDMs retains slugs in the workpiece via a reverse discharge brass ad-hesion process, leaving small islands of soft material that hold slugs in place. After roughing, a few light taps with a plastic or 28JULY 2019EDM.indd 28 6/18/19 9:56 AM'