New to WEDM - Suggestions?

Hello all,

I have been sub'ing out a fair amount of WEDM work (also not quoting work that requires it) and I am starting to consider the idea of getting into an older machine to keep this process in house.

The one major hurdle is, I've never run a WEDM before and I'm looking for some resources to get more familiar with it Are there any good books outlining basic operating principles, procedures, techniques, workflow, setup, etc? There is a lot less info out there on the internet compared to milling!

Are there any specific brands or models of machines that are more forgiving for a newb like me? There seem to be a lot of used Brother, Fanuc, Mits, etc available online and I was wondering if there are any I should look closer at and any I should avoid...

I am not looking for utmost precision (0.0005" - 0.001" is acceptable) and a working area of ~12"x12" would be ideal. Most parts are usually from sheet material (<0.100" thick), and occasional flat bar up to ~2" thick. I would hope to be able get into a capable machine for <$20k, but please tell me if I'm way off on this!

Cheers

Hi,

Things to consider:

Tooling can be very expensive, if you buy a $20K machine you
could easily pay that much for good tooling - many people make
their own.

You will want a machine that you can still get support for locally.
Paying for a guy to fly from LA and stay in a hotel $$$.

For Mitsubishi machines you have to pay for an annual fee ($2,000 or so)
before they will even talk to you about support issues.

Brother machines were great, but brother sold their EDM line to Charmilles,
and they no longer support the brand.

I know nothing about the Sodick machines.

I have an older Charmilles robofil 500F, and their local support has been great.

Makino has some of the best machines but they are very expensive.

Wire EDMs are very fussy about maintenance, it needs a lot and often.

If you want to make money you will want a machine that has a good
reliable wire threader.

A submerged tank WEDM will the best over all, but just a jet spray will
work just fine for what you describe your work to be.

If you want to do fussy work (medical, aerospace, etc.) , that is sensitive to
recaste, then you will need a machine that has a modern power generator that
does not produce much Heat Affected Zone (HAZ). This will be most likely be found
in a early to mid 2000s (and later)machines. These power generators are called by
many names AC, and non electrolytic (no electrolysis)...etc.

A book, by Bud Guitrau, The EDM Handbook, is a good place to start learning.

The cost of expendables, like wire guides ($800 to $1000s), wire cutters, and
carbide electrical wire contact.

Good luck - Paul

just my 2 cents. charmilles machines have collision protection. this can be a life saver for newbies! Also,they do not charge for phone support. if machine is still supported all calls are free. im not saying others dont offer this but i KNOW Charmilles does.

Ive worked with a few different machines and the makino was a good machine but I'd say mits is the better as it's what I'm most familiar with. If you can find a mits fa10s for a decent price I'd go for it. It doesn't have touch screen but it's still easily navigable. As long as you keep up with basic maintenance especially powerfeeders and diamond guides threading will be fairly uneventful...it's not 100% fool proof though, none of them are. Consumables are wire, powerfeeders, diamond guides, resin bottles, filters, and rollers. Wire is by far the most common.

It's an expensive hobby to get into but it can make some good money too.

plastikdreams said:

Ive worked with a few different machines and the makino was a good machine but I'd say mits is the better as it's what I'm most familiar with. If you can find a mits fa10s for a decent price I'd go for it. It doesn't have touch screen but it's still easily navigable. As long as you keep up with basic maintenance especially powerfeeders and diamond guides threading will be fairly uneventful...it's not 100% fool proof though, none of them are. Consumables are wire, powerfeeders, diamond guides, resin bottles, filters, and rollers. Wire is by far the most common.

It's an expensive hobby to get into but it can make some good money too.

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And whatever you do, have the factory rep come out at least once a year to do a pm. It's costs a bit and can take a few days but it's worth it to make sure everything is in the up and up.

This was supposed to be an edit to my first post...oops

I'm the OP and bumping this up again. Covid put my WEDM plans on the backburner, but I am starting to get serious about this again....

Just to re-define my intended use (to perhaps guide the choice of machine)... The bulk of the work I plan to put through this machine is not necessarily "wire" work. It will primarily be the outer profile / gauge section of tensile specimens. Very easy, relatively low tolerance (+/- 0.001"). The reason for doing this on a WEDM and not the mill is to allow the machine to run unattended (i.e. overnight) so that I can increase my throughput. Load up a bunch of different geometries, and push the green button (easy as that, right?). I'm a one-man show, and with my low cycle-time parts I could not efficiently run two mills at the same time.

There is a '99 Fanuc Robocut α-1iA for sale near me (southern Ontario, Canada), and I am going to have a look at it. Having no experience standing in front of one of these... Is there anything I should be asking the owner? Apparently it has been "very well maintained". Is this machine going to have a reliable AWT? Can I restart at the breakpoint and thread through the kerf (seen that advertised by a few companies...). The price on this is $30k USD, which seems expensive, but who knows....

Thanks for the insight.

With tensile specimens, there are some potential issues with edge condition from thermal/chemical effects of EDM. It might be worth investigating that before spending money on a machine.

If that's not a problem for the sort of testing you're doing, have at it. But I think I'd rather do them on a mill, with a sharp cutter for finish passes after the profile was roughed out.

Milland said:

With tensile specimens, there are some potential issues with edge condition from thermal/chemical effects of EDM. It might be worth investigating that before spending money on a machine.

If that's not a problem for the sort of testing you're doing, have at it. But I think I'd rather do them on a mill, with a sharp cutter for finish passes after the profile was roughed out.

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I assume this is the "recast" you are referring to? I see a lot of newer machines advertising advanced power supplies which minimize/eliminate this effect. Would this '99 Robocut be one of those?

Some of the complicated custom geometries have to be wire cut anyway (currently sent elsewhere), so I don't believe this has been shown to be an issue for this customer. But yes, definitely worth confirming this first!

e30ryan said:

I assume this is the "recast" you are referring to? I see a lot of newer machines advertising advanced power supplies which minimize/eliminate this effect. Would this '99 Robocut be one of those?

Some of the complicated custom geometries have to be wire cut anyway (currently sent elsewhere), so I don't believe this has been shown to be an issue for this customer. But yes, definitely worth confirming this first!

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I'm not an expert on EDM, so hopefully one of those guys will chime in, but yes, not just recast, but there's additional effects that less sophisticated controls can impart on the material. It wasn't until recently that some parts could be made by EDM for some Mil/Aerospace contracts for this reason.

But if you've already done such work for customers without complaint, then maybe you'll be fine with an older machine.

For what it's worth, over the years I've cut hundreds of tensile specimens for multiple customers on a wire.

As for that specific machine, I've run many of them over the years. There is still good tech and parts support, at least in the US. The threader works...okay. It was not the fastest or most reliable but it generally worked as long as it was maintained. Threading in the kerf isn't going to happen. The next generation Fanuc with the newer control and threader was a lot faster and more reliable, and the control was a lot better.

For your uses it's probably fine, as long as your seller demonstrates the AWT cutting and threading well that part should be good (if the machine isn't under power I'd stay away). Another thing I would look at is to fill the tank up with water and see if you are getting any big leaks around the arm or tank seal, that's probably a pretty good indication of how it was maintained.

I would also ask to see a test cut performed and make sure it cuts close to the rated speed with no wire breaks.

@wdevine thanks for the details. I definitely want to see it cutting, threading, etc. Thanks for the tip about checking for leaks on a full tank. I guess this '99 machine is now getting pretty old in terms of WEDM technology. I assume WEDM tech has improved much more over the last 20 years than milling/VMC tech has.... When you say the "next gen Fanuc" what years/models are you referring to? Just so I can keep an eye out to get an idea of the price point...

For shits and giggles I did get a ballpark quote for a new Robocut C400iC for $147k USD. A bit cheaper than I was expecting, really, but not attainable for me at this point.

I also have a quote from EDM Network (a few years old now...) for a new CHMER G32S for $102k USD. My gut is telling me I either should get into some new (warranty, performance, implied reliability, etc) or something really cheap (<$15k) and have a go at it.

Whatever you buy, you are going to need consumables (wire, guides, contacts, filters, resin) and occasionally parts. Stick with a brand name and make sure you have a distributor who can service and give you applications support. There is a whole lot more maintenance for wire work than chip making, and you will need help at some point. If you have a distributor who can furnish training (it won't be cheap) I highly recommend it. Not everything is intuitive with EDM, factory support is really helpful when you are getting started.

e30ryan said:

@wdevine thanks for the details. I definitely want to see it cutting, threading, etc. Thanks for the tip about checking for leaks on a full tank. I guess this '99 machine is now getting pretty old in terms of WEDM technology. I assume WEDM tech has improved much more over the last 20 years than milling/VMC tech has.... When you say the "next gen Fanuc" what years/models are you referring to? Just so I can keep an eye out to get an idea of the price point...

For shits and giggles I did get a ballpark quote for a new Robocut C400iC for $147k USD. A bit cheaper than I was expecting, really, but not attainable for me at this point.

I also have a quote from EDM Network (a few years old now...) for a new CHMER G32S for $102k USD. My gut is telling me I either should get into some new (warranty, performance, implied reliability, etc) or something really cheap (<$15k) and have a go at it.

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The generation Fanuc I'm referring to would be called a 1ib or 1ic, they would range from 2001-2006 or so. The next generation starts around 2007 with the 1id and then 1ie and it is another step up and is very close to the new C400 you had quoted. Used machines from this period are probably in the 30-50k USD range.

I also have a LOT of experience with Chmer, where I worked before we were one of the first companies to buy them from EDM Network back in like '98. They are pretty solid machines, however they are not nearly as user friendly for someone new to EDM than the bigger brands like Fanuc, Mits, Sodick and Makino.

I don't know if I can recommend spending as little as 15k on a used wire. They are much more sensitive to maintenance issues and something that cheap is going to be a giant pain in the ass for multiple reasons.