I just came across someone that did a DIY EDM machine built into a 3D printer machine. I wonder how beneficial this would be as an Add-On to your AVID CNC.
The water tank/flow could hang between extrusions or you could create a vat with part/piece holder. I searched the site for EDM and didn’t see an entry so I thought I would add it.
How does this EDM method compare with the plasma cutter that is currently available.
They both cut conductive metal?
And that is about it… 
You will not find wire EDM on a machine like this without a serious amount of customization.
I would do the smaller DIY projects because when they are small they work great. When you get larger things don’t scale as you would hope.
EDM will always be higher quality than plasma. Plasma produces a dirty, ragged, tapered edge. The parts I cut with EDM are nearly perfect.
Another thing most folks don’t realize about EDM is that wire runs from top to bottom and out to a rewind spool.
So if you want to cut a shape in the center of the piece you have to first drill a hole through the work piece and then thread the wire through that hole and back out to the rewinder reel (or chopper).
That is why I don’t think I have even seen a larger moving gantry style EDM. The cutting head and wire stays stationary on the machines I have used while the stock is moved around in the X and Y on a platform under the water. So the tank is much larger than the cutting envelop with the wire entering from the top in the center and exiting from the gland nut and port on the bottom where its either rewound onto a waste reel or chopped into bits.
Oh, and that wire reel moves pretty darn fast. It is single use… and you think end mills are expensive 
A lot of the die-sinker style EDM machines have at least an X-Y table on them. One of the first electrical contract jobs I did was to build a 3-axis stepper motor control system with closed loop feedback to attach to the lead screws on just such a machine. The customer had these small ~2in x 2in parts that they wante to go in and brun some crazy “S” shaped Tee slots into. These parts were pre-hardened steel that they did not want to anneal and re-harden. The beautiful thing about that is that if the sampling rate and filtering rates are high enough on the ADC (challenging back in '91~'92 when I did this work) one can dial in a spark gap and maintain a very good finish. The hard part about that job, was of course, all the back up steps to open the erosion face for flusing have to back track the path the electrode was falling. Just like with any old Tee slot cutter on a mill, there is no simple retract. This was just complicated by the tracks not being straight, so backup was a curve back in the direction things had just come from.
I would put this form of machining definitely in the “advanced” category. Even today its a total pain in the pants. But the results are scary perfect when it goes right.
I use to have a sample in a tiny bottle of mineral oil and the core of it would slide out and back as you tilted the bottle. When it was upright you could not see the palm tree cutout in the center. When you leaned it over the core or palm tree with slowly slide out and stop at the top of the bottle. Really cool.
Oh, I just got time to watched the video. Kickstarter. Its a brass rod electrode and its cutting 1mm aluminum at 10mm per minute.
Its cool. It is but I wouldn’t swap it for the 400 ipm or better I already have.
Once that electrode meets thicker material it will not last very long which is why they use the continuous wire for big commercial projects.