marknabia,
I'll toss in a bit of information since I was in the wire edm business for a good while (semi retired now).
As jmullett said: a wire edm machine really has to be treated very differently from most/all other machines in the shop. A wire machine will generally require the most preventative maintenance of any machine you own. They are typically not a machine you ... decide to use on a particular day, walk up and hit the ON button and be cutting a part 15 minutes later.
If you want very good accuracy, you really need climate control. Cleanliness is everything. That little wire usually runs through a bunch of guides, rollers and tubes both on its way to your workpiece and on its way out of the machine. The tiniest little piece of debris lodged somewhere can cause a short circuit and the machine will refuse to cut. Fanatical cleanliness will make your life easier -- I can't stress that enough.
You mentioned the materials you were cutting, and plain carbon steel and tungsten are about the dirtiest materials to cut. You will go through filters fairly frequently, especially if you are doing "tall" cuts with 0.25mm wire.
Another thing to be aware of is tooling costs (work holding). If you're not familiar with them, look up the names "Erowa" and "System 3R". This is probably the cream of the crop in work holding. Can you do without high end tooling and/or make your own?... yes, it's possible, but the nice tooling spoils you if you plan on doing very accurate work. I've used both extensively, and prefer Erowa... primarily because if you have parts that get worked on in a CNC mill *and* in a wire machine, Erowa builds really great work holding tools for both. Transitioning from one machine to the other can be extremely simple and accurate, as a "holder" can be taken from a wire machine and moved right into a mill (or visa versa). All depends on what you're going to be doing.
One last "word of warning" (for this message at least, haha!) -- wire edm can be frustrating. There is not a lot of information out there. It takes a while until one gets used to thinking "inside out" some of the time (at least that's what I call it). The learning curve is steep... at least if the desire is to get really comfortable and good at it. Machine crashes can be >VERY< espensive, so double and triple checking everything before hitting that green button is important. Wire machines don't really give you the ability to just...'comp the Z up a few inches and dry run the part. Extreme caution is a good thing when starting out.
Fire away if you have questions.
PM
