CNC Wire EDF Project

Hey all! I’m in the beginning stages to build an Electric Discharge Machining system. If you don’t know what this is EDF is a method used to basically erode two metal parts that are near each other. For Wire EDF this means a wire which is charged with high current passes near a piece of metal. By constantly replenishing the cutting wire, the part to be machined is cut, and the wire is replaced before it can be completely eroded. When done well, this is a highly accurate cut with extremely small kerf and very good surface finish. It can also cut very tight corners, and will cut anything conductive. Think hardened steel, Titanium, Tungsten etc.

I’m posting here because I plan to use Smoothieware for the main control board, with a few modifications to the software. The challenge is to create a variable feed rate that reacts to voltage at the cutting interface. I hope to start with the config setup of a laser table, and find help modifying the firmware to accept an input indicating voltage level then control the cutting speed based on this.

Another project, which I have someone working on now is creating the Arc Generator. This will control power to the cutting wire and will be controlled with pulses from an Arduino DUE board. This Arduino will also have a WIFI shield, and run an HTML page to allow the user to change pulse settings. This will control the timing, and power of the pulses. Other ARC generators use custom software running on a PC and connected with an serial interface. I want to simplify this, and eliminate some wires. Minimizing wires is important, because the ARC generator, creates a lot of EMF, and the cutting wire transmits it well. I may sell ARC Generators, or the circuit board & parts list so anyone interested can create their own.

Later I may consider selling machines, but for now I’m focusing on making one machine that works. I may make a youtube series when I start building. Right now it’s in the planning stage. I have about 5 pages of documentation based on what i’ve learned from 3 different youtube series. Applied Science is the first one I ever saw & he learned some of his stuff from BaxEDM.

Another big part of the wire EDM process is cooling, and flushing material from the cutting location using water. So this machine will have high power electronics & water in contact with each other. How could it get more dangerous? Well I’m not the first one to do this, and Electricity and Water can be mixed of you’re careful. Need I mention SAFETY is a big priority! I plan to have the ability to start & stop the machine from a safe distance & it will have a big red warning light to remind people not to touch the machine while it’s running.

I have lots of experience with 3d printers, aquariums, electronics & welding. So why not use all that to make a large EDM station? I built a 3d printer that has a working area up to 25X25X20 inches. It uses linear rails, and ballscrews so to save money I’ll probably use parts from that to make the X-Y movement system.

Later when things are a little more ironed out I may post my features list. It outlines the tasks for each
sub-system, and a rough description of how each works. It also helps me avoid feature creep. The tendency to add too many features which can make a product too expensive and too complicated.

Any ideas from this forum are welcome. Especially for now I’d love ideas on how to get Smoothieware to adjust the movement speed of the X-Y table based on the actual arc voltage once metal (almost) meets metal. It needs to even move backwards on case of a short circuit. This can sometimes result in recovering a difficult cut.

I’ll try to check back here frequently. I drive a truck for a living, so sometimes I can’t get to the internet, but this project is very high priority for me, as is sharing what I’m learning so others can learn from me.
In the words of John C Maxwell " “It’s said that a wise person learns from his mistakes. A wiser one learns from others’ mistakes. But the wisest person of all learns from other’s successes.” I hope we can learn from each other here & create a success to inspire others.

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One of these has been in the back of my mind torturing me for a while, as is a water jet cutter.

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