The key word here is DISCHARGE. This is how it all works.
The electric current flowing through the brass wire jumps across a tiny little gap through the deionized water and hits the metal workpiece. The power in the electric current then virtually vaporizes the metal to be removed. BUT, there’s one thing that has to take place before an operation like this can happen.
A hole through the workpiece has to be created in every single spot where a wire edm operation needs to remove metal. The wire needs to thread through the hole either manually for smaller jobs or automatically with auto-threading capabilities for production jobs that can run for days. This is where EDM hole drilling comes in. Whether it’s preparing production jobs to go into the machine or popping holes for customer’s parts, manual and CNC hole poppers, which use a program, are designed to do the trick. Many customers need holes in very hard materials or in places that are hard to make with conventional machining techniques. The hole poppers use precise brass tubing of a particular OD/ID that picked for the job. It’s held in a precision holder that spins and moves downward at the same time. The workpiece is constantly flooded with water while the electric current jumps and removes the desired metal. Some jobs require as little as one hole and some can require hundreds and hundreds of starter holes.
Like any equipment, there has to be trained operators that understand the subtleties of the operation. The size of the tubing, the speeds and feed rates, the amount of water, etc. can all contribute to a perfectly sized and located hole. If done right, the hole will run straight through the work piece and not “walk” even the slightest bit sideways.