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which EDM machine?

Mark Winsor

Aluminum
Joined
Feb 4, 2013
Location
Hartford, CT, USA
Hello, My shop currently does not have a wire EDM, but I'd like to add one in the near future.

It does not need to be large, 4"x4" XY travel is enough for 90% of my work.
Accuracy would be nice, but for most work +/- .002" is good enough
It does need to accept CAD files of some kind and cut "complicated" splines, which can make longer programs
Auto-threading would be a bonus, as the cuts are largely discontinuous

What would a reasonable $ amount be for something like this, and what are some possible brands/models I could research? So far I have found the Hansvedt stuff, but it's not clear which models would work for the splines, and there don't seem to be many on the market.

Is it common for shops to sell "worn out" machines when they lose the tenths accuracy?


Thanks!
 
Hi Mark:
Are you looking for something cheap and used, or does your budget allow for a new machine?
Are you looking for a specific set of capabilities like large taper cutting ability or speed or precision?
Do you have the space in your shop to accommodate a large machine or are you restricted in size?
Are you good at fixing cranky CNC machines or will you be fully reliant on tech support to keep it running?
Are you looking for a project or a tool?
Will you accept uncertain reliability to get a cheap machine?
Are you by nature fussy and persnickety about your tools and your work or are you by nature reasonably relaxed about such things?

By way of some answers to your questions here's a summary of my experience:
I bought a reconditioned Sodick A320 vintage 1996 from EDM Network in Illinois in 2008; my introduction to wire EDM.
I bought a 3 day training course with it.
I had the machine until 2011 when I traded it in for a brand new Chmer which I still own.

The Sodick was a pretty simple machine with no power Z and no autothreader but I got it with a rotary axis which was necessary for my work.
I cut a lot of stuff on it, some of it quite fussy.
It was tired when I got it and its reliability (rather it's LACK of reliability) was a problem right from the outset despite the limited warranty I got with it when I bought it.
I had board failures, and computer failures, and drive system failures and discharge cable failures, always at inconvenient times.
Fortunately the Sodick was cheap to fix, and I had superb support from Larry Wetmore at EDM Network, so I was always able to get the old girl running again.
However, I also had accuracy issues and had to compensate for those with creative programming.
The machine cost me about 40 thousand Canadian dollars when the Canadian and American dollars were about at par.

I bought the Chmer to solve those problems with the Sodick.
Nice convenient machine (except for the horrible Chinglish manuals).
It's a mid class machine, not that accurate (tenths rather than split tenths) not that nicely fitted (think Chevy rather than Cadillac), and pretty basic in capabilities but pretty bulletproof too once the teething troubles were sorted out.
Those were mostly to do with getting it to talk properly with the rotary axis I bought for it, but EDM Network eventually sorted all that out too, and it's run reliably since then with almost no hiccups at all.

I paid about 120 thousand for it, so three times the price of the Sodick, but I got five times the machine, so it was worthwhile for me to do the upgrade since I had become pretty dependent on having the capability to hand whenever I need it.
It gets the second most use of all the machines I own, and has been a steady moneymaker for me.

I have seen equivalent machines to the Sodick on Fleabay for ten thousand dollars but with no rotary axis (they're EXPENSIVE) and no support.
If you get lucky they're good, simple easy to run and maintain machines; if not you'll likely have a similar experience to mine.
If you go this route, a tech who knows the guts really really well is essential unless you have tons of time to fart about diagnosing and fixing it.
Larry Wetmore was very good indeed, but I haven't been in contact with him for several years, and he was a Sodick guy, so he is most useful only if you go with that brand.
If you buy a Swiss monstrosity from that era, you'll get the remnants of a Ferrari, but with Ferrari prices for service and parts too, so be warned.

If you go new, what you can get depends on the size of your pocket book; my personal hard-on is for a Makino but I couldn't justify the price so I bought the Chmer for half the price.

Whatever you do, don't get an orphan...you'll likely never be able to keep it running, and the first board failure will leave you with a boat anchor.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
www.vancouverwireedm.com
 
Mark,

The one thing you don't want to forget about are the things that
come after you purchase a machine.

Tooling is a major factor. Where else could you spent $3,000 to $10,000 for a vise?
A new tooling ruler/rail for my machine is $13,000.

Consumables is another on-going cost - wire guides can cost $1,000+

If you don't like to do maintenance on your equipment don't buy a wire EDM.
Your fundamental success with a wire machine will depend on how meticulous
you are at doing the routine maintenance. Depending on the materials you
cut, maintenance, at a minimum, is a weekly requirement.

What Marcus didn't say was how expensive replacement parts can be if
you buy a well (not well) used machine.

Depending on what kind of work you do, you may not be able to buy
an older machine because the older machine didn't have AC generators.

If you want a good, but somewhat out of date book to read, get Bud
Guitrau's book "The EDM Handbook". He includes many topics that should
interest someone who wants to get into EDM.

On auto-threading - many older machines (mid 90's) have auto threaders, but
they tend to be finicky, slow, and not to work all the time. As you get into
the 2000's era machines they tend to have AC generators and their auto-threaders
generally work more reliably and faster, and some will even thread in the kerf.
In the kerf means you don't have to go back to the start hole, and retrace you path.

If you are going to do the cutting on pre-hardened steel you will need a EDM hole
drill/popper to make the start holes.

The next question, will you need a submerged cutting machine for the type of work you do?

If you get serious, before you buy you need to find out what local support there
is for the machine you are interested in, especially if you are thinking of buying
a used machine. Mitsubishi wants a $2,000+ service fee before you can even talk to them.

If you buy a real old machine, you better make sure you can still get all the parts.
Many manufactures don't provide support for some of their older machines.

I would say that all most all wire EDM machines will do splines as long as your CADF/CAM
program will generate the code for it. I would say the Hansvedt machine are at the bottom
of the spectrum of wire EDM machines out there and the Makino machines are at the top
of the spectrium. With many players in between.

That brings up another issue, will your machine be supported (can you get a Post for it)
by your CAD/CAM program.

There are so many issues to consider before jumping into wire EDM.

Do your due diligence and you will not be unhappily surprised.

Paul
 
I like the sodiks makinos and agies...used em all. For the last two years I've been involved with mits machines. We have some older, 10 years or more machines that still hold tenths and are worked 24/7 excluding holidays lol...granted we have 2 guys who's only job is weekly and monthly pm's...with a yearly pm done by mits. We have 32 sinkers and wires, 3 hole poppers.
 
Hi guys,

Are you looking for something cheap and used, or does your budget allow for a new machine? Cheap and used

Are you looking for a specific set of capabilities? Nothing unusual, just .002" accuracy (should be easy!) and autothreading

Do you have the space in your shop to accommodate a large machine or are you restricted in size? No size restriction, just was thinking smaller could be cheaper

Are you good at fixing cranky CNC machines or will you be fully reliant on tech support to keep it running? Tech support

Are you looking for a project or a tool? A tool

Will you accept uncertain reliability to get a cheap machine? I am accustomed to and happy with Haas tech support, as a benchmark

Are you fussy about machines? I am more interested in the finished parts than the machine in this case, and because I'm not trying to push accuracy or speed to the limits of technology, was hoping to find a cheaper (worn out?) machine that fails to meet someone else's needs, but would meet mine.

A lot of good points were made about maintenance, consumables, and service, thanks.

The options seem to be mid 90's machine for 10K vs. 30K for mid 00's. Is the auto-threading really that bad before 2000? I would be threading through pre-drilled holes that can be .250" diameter, if that matters. And cutting .030" wide slots in 3/4" thick steel.

Assuming I'm sticking with major brands, would getting a post for Mastercam be any different for a 90's machine vs. 00's?

Thanks for the advice so far, very helpful
 
auto thread is a curse and a godsend, basically maintenance needs to be kept up pretty well for it to keep working well. tensioners, power feeders, and the cutting mech all play a big roll in it. ive threaded through the kerf many times, .250 is like throwing a hotdog down a hall way. Fortunately when i started at zimmer i had enough operating experience that I was able to focus on the maintenance aspect a lot more. Wire machines can be finicky bitches, but its not hard to keep them going with a little guidance.

I dont have a post for the machines at work, so I program in mastercam as if it was a mill with a custom tool the size of the wire plus overburn. I then cut and paste it into a random program I have. I do have to manually enter things like wire cut/thread epack changes and stuff like that...but its simple enough. If you are going to do multi axis taper programming having the post is a must.
 
Hi again Mark:
There are some contradictions in your requirements that you will have to resolve to get to your decision on what to buy.
First, be aware that wire EDM's typically do not "wear out" mechanically like most chipmaking machinery does; everything happens at a stately pace or slower on a wire.
Rapids might be 50 IPM or so, cutting happens at small fractions of an inch per minute, and cutting forces are essentially zero.
So the motion guts last a long time unless the machine is crashed, dropped in transit, starved of lube or otherwise mistreated.
Subsystems like pumps and wire transport mechanisms do shit the bed, but these are typically more easily fixable and can be cobbled together from non OEM parts if necessary
The overall outcome of this is that wires typically either work or do not work when you flip on the power...there is no "worn out that fails to meet someone else's needs but meets mine"

What makes the screen stay black when you flip the switch is the electronics.
I have a personal theory that the management of high currents in a nasty wet environment take their toll, also components like capacitors have finite lifespans, so boards go and computers go and hard drives go etc etc.

Old machines are not typically re-buildable by just calling the OEM and demanding replacement parts: most parts are long out of stock so you're looking for good used or rebuilt parts and that means your machine has to be popular enough that someone cares to keep parts and know how available, AND YOU HAVE TO FIND THEM while your machine is down and your customers scream at you.

My oldie Sodick was maintainable only because Mr Wetmore had been a Sodick tech and felt he could sell enough machines to guys like you and me to justify stocking parts and keep his electronics guys in milk and cookies with repair work.
The same is true for machines like the older Agies and the Charmilles machines; there is a grey market around that keeps these brands going even for twenty year old machines because they were the cream of the crop in their day and there's enough interest in them still to keep the parts market alive.
Some comes from old codgers who bought them new and see no need to upgrade and some comes from guys like you and me who want into the game without shelling out the big coin

However, when you want cheap, serviceable and reliable you're asking for the equivalent of fast good and cheap, and everyone in the machining business knows you only get to pick two of the three.

I was not able to get "reliable" for a 40 grand investment, and EDM Network is a good reputable company that does its best for its customers.
But it was a ten year old dinosaur when I bought it and no promises or warranties can overcome that reality.
Now the same machine is a twenty year old dinosaur!!

A ten grand Fleabay special is a crapshoot, and will always be a crapshoot.

So resign yourself to accepting either a large capital cost or a project rather than a tool; you'll get a great machine for cheap only if you luck out bigtime, and you'll never know what you got until ten years have elapsed.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
www.vancouverwireedm.com
 
this is very true, in the past year some of our machines have needed boards, some old and some new...these repair bills are easily into the 20k+ range at times, plus the machine down times. there is nothing cheap about edm...my company is a multi billion dollar company, they can throw that money at the machines...can you?

to break it down...
improper control working:
control pc board: 11k
mits tech: 120 an hour
trouble shoot maybe 1 or 2 hours
repair maybe 3 or 4 hours
testing: maybe 2 or 4 hours

heres another...
wire keeps breaking in the cut, no matter how we change the current etc:
mits tech 120 an hour:
initial Troubleshoot/cleaning: 8 hours
Replace rollers: 3000 dollars and 4 hours, doesnt fix it
rebuild upper and lower heads: 6000 and 8 hours, doesent fix it
test electronics: 7 hours
New power supply: 30k and shipping, and 6 hour install, and 4 hours testing and adjusting, fixed it

again, for us its a drop in the bucket, we can move product to other machines and afford it...can a small business?

i love edm it does what other machine tools just cant efficiently and effectively...if you need it, you need it...if you can farm it out, do it.
 








 
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