Wire EDM and what I've learned from it

A project log for Sinker EDM Machine

Like a hole puncher, but for metals. For your shelf or desktop.

dominik-meffertDominik Meffert 04/23/2022 at 12:200 Comments

Wire EDM Machine

I spent the last weeks and months learning how to build an EDM Drill and Wire EDM machine and although I could successfully build and test both machine setups they are both not what I want to achieve with this project.

The EDM Drill worked well, but I did not like the way the workpiece was clamped to the Y-axis, and because the electrodes that I used (4mm brass tubes) were not straight, but slightly bent, the rotation was wobbly like a bent drill.

The Wire EDM machine did also work very well - as long as the wire did not break - what happened randomly, no matter what I tried to prevent it from breaking.

The cuts were very clean and precise, but because I could not finish a single workpiece without at least one wire break, I think that no one of you would bother to work with such a system. I also spent around 100€ on a 10kg spool of EDM wire, which makes it quite expensive.

So, what should I do next.....

The goal of this project is to build a machine for cutting metals that you can use in your apartment at any time of the day without getting in trouble with the neighbors - So no noisy CNC mill/router or plasma cutter that needs a loud air compressor. 

The machine should also be cheap with no expensive consumables.

And the most important thing:

- It has to work!

The machine should be as reliable as a 3D printer, where you can start a printing job and leave for the next 8 hours, just to find a finished print on your machine when you come back.

To achieve this goal, the machine has to be fail-safe, which is easier to do with machines that did not apply force to the workpiece like a laser, plasma, water jet - cutters, and 3D printers and harder to do with CNC machines.

If everything works as it should EDM machines do also not apply force to the workpiece, but only because they can sense the current or voltage between electrode and workpiece to keep the right distance. If now the electrode or workpiece gets covered with some not conductive material from the cutting process, the machine can no longer keep the right distance to the workpiece and so the electrode or wire can crash into the workpiece which leads to a wire break, lost steps or incorrect positioning.

Because this error can happen at any time I have to build the machine in a way, that this error will not lead to a failed machining job.

More about that in the next build log.....