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Wire EDM machine

Mcgyver

Ultra Member
BAXEDM is really targeting retrofits though, of commercial machines that have antiquated or failed eletronics.

What is your view of the complexity and challenges of his controller? What are the tough mountains to climb?

I can see how it would be in constant use if I had one, but its just not happening at say $7000. But that rational economic thought doesn't dispel the burning want for a machine I don't have :oops: (yes its like a disease)

I probably don't have enough electronics skill to design the controller (probably as I'm not sure what the challenges are) but would gladly be part of the mob following along :).
 

gerritv

Gerrit
Based on my reading of papers and patents, the pulse is stepped. At 70vdc, and a variable duty high pulse rate. Lots of mosfets so that everything is controlled by software, no toggle switches. Add in current measuring so you can manage the gap and also use the wire for touch probing the edges.
There is a Polish machining forum where they are also experimenting. One person posted his linuxcnc config files, he at the time wasn''t backing out of the cut on a short, just waited until the wire cleared the short. A bit slower but no magic reversing code required.

My analog skills are mediocre, but my brother is great at it so he will get tapped at some point to help me, once I get going.

Most of the research papers in recent years are from China, an indication of what they see as a critical machining capability for precision work:
 

Attachments

  • Pulsed Power Supply for Micro-EDM Triode Avalanche.pdf
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historicalarms

Ultra Member
Damn someone's gonna want to shoot me...3 weeks ago I turfed about 10 yrs of Home Shop Machinist magazines in a "basement/gunroom cleanup and that whole EDM build series was in there....I offered them up to two aspiring hobby shop friend (Calgary & RD) but both refused, shipping was too much to make it worth while so just thought that would be the same answer on here....and out they went, damn again.
 
Based on my reading of papers and patents, the pulse is stepped. At 70vdc, and a variable duty high pulse rate. Lots of mosfets so that everything is controlled by software, no toggle switches. Add in current measuring so you can manage the gap and also use the wire for touch probing the edges.
There is a Polish machining forum where they are also experimenting. One person posted his linuxcnc config files, he at the time wasn''t backing out of the cut on a short, just waited until the wire cleared the short. A bit slower but no magic reversing code required.

My analog skills are mediocre, but my brother is great at it so he will get tapped at some point to help me, once I get going.

Most of the research papers in recent years are from China, an indication of what they see as a critical machining capability for precision work:
Wow! I think we are going down a rabbit hole here!

Polish is my second language but you can just as easily translate with Google if you want to know what is being said on the Polish forum. I'm wondering tho if its really necessary to be reading the latest research papers on the subject. EDM was already being used in industry for decades. We just want a smaller simpler and cheaper version for the home shop.
 

gerritv

Gerrit
The problem/issue is that wire edm has differrent generator requirements from plunge edm. The wire is thin, breaks easily and is subject to erosion. And it is slow if using the simple RC type generator. So a more sophisticated generator design is beneficial to improve cut performance as well as not breaking/zapping the wire.
The mechanical part is relatively simple, although again wire tension control is important.
The amateur power supplies is wrapped in secrecy, lots of hints but no schematics. If/when I go ahead I plan to contact one of the 'originals' directly, at one time they shared freely on a Yahoo group, long lost.

If you are going to the trouble of designing and building the meachnics, it would be lovely to have something that performs well, not a constant irritation. Hence te desire to get it mostly right at the start.
 

gerritv

Gerrit
Damn someone's gonna want to shoot me...3 weeks ago I turfed about 10 yrs of Home Shop Machinist magazines in a "basement/gunroom cleanup and that whole EDM build series was in there....I offered them up to two aspiring hobby shop friend (Calgary & RD) but both refused, shipping was too much to make it worth while so just thought that would be the same answer on here....and out they went, damn again.
Those articles are all archived on someone's pc, i'm sure :) However none show Wire EDM, a bit different animal.
 

gerritv

Gerrit
for a good overview/comparison. For one thing, in plunge edm you have to make a master, wire edm you can cut any shape. And cut at angles, such as for punching dies.
 

Mcgyver

Ultra Member
Why is wire EDM so desirable? Surely a lot of EDM advantages can be had with plunge EDM?

Plunge will make holes, or burn out a tap. With wire you can cut out shapes, internal or external, so long is the profile is all the way though the part (no pockets or blind holes). Really fancy ones even let you angle the wire. There is almost no similarity in what they'd be used for.... for me, a sinker is recovering from a mistake (broken tap) while a wire opens up new possibilities on what can be created, or at least created easily.

just skip to about 6:00 and you can see a simple example.
 
Plunge will make holes, or burn out a tap. With wire you can cut out shapes, internal or external, so long is the profile is all the way though the part (no pockets or blind holes). Really fancy ones even let you angle the wire. There is almost no similarity in what they'd be used for.... for me, a sinker is recovering from a mistake (broken tap) while a wire opens up new possibilities on what can be created, or at least created easily.

just skip to about 6:00 and you can see a simple example.
Ya I get it. Personally I would be happy enough with a plunge diy EDM. Other advantages of plunge EDM is that holes are very accurate and hardness of the target doesn't matter. So you can just as easily cut holes in HSS for example if need be. If I want to cut out shapes I will use my plasma cutter.
 
I agree with @gerritv that wire EDM does not yet appear to be in the viable zone as a useful DIY project. Its expensive, slow, and prone to down time. Plunge EDM on the other hand seems like potentially an entirely useful DIY project.
 

kstrauss

Well-Known Member
I agree with @gerritv that wire EDM does not yet appear to be in the viable zone as a useful DIY project. Its expensive, slow, and prone to down time. Plunge EDM on the other hand seems like potentially an entirely useful DIY project.
I would love a wire EDM for projects involving flexures (see
for the sort of things that I would like to be able to make). I doubt that a plasma cutter can provide the desired accuracy<G>.
 

Mcgyver

Ultra Member
If I want to cut out shapes I will use my plasma cutter.

I doubt one would be a very satisfactory substitute for the other :) You can get accuracy to a few 10ths with a wire EDM. I think something like the BAX is really close to a feasible DIY EDM....actually its more than feasible, its doable but just too bloody expensive for most us. If the expensive commercial controller challenge was cracked, I think I'd be building one.
 

Dan Dubeau

Ultra Member
We should all chip in and build one, as a time share project. I doubt any of us would use it frequently enough to justify the cost of full time ownership, but if you could book it for a month or two, and stack up projects, it could be feasible.... Of course there is a long list of negatives to doing something this way, but think of it like a library book, that happens to slice through steel very accurately. :D.

I'd love to have one, but also can't justify the cost. The few WEDM projects I've needed I've shoved to our vendors at work. $$$, but very good quality.
 

Mcgyver

Ultra Member
I'd volunteer to house it...but not sure if I could fit it in:)

I think I'd use it a lot. The home use dynamic is different than commercial. Its slow so is expensive so you only use it when you need to commercially. At home, I could care less if its slow, start it up and go do something else.

Currently I'm making some minature tripan style tool posts & holders. You wouldn't send it out, you'd mill it which is what I'll do, but man, would ever be nice to have a wire edm burn it while I did something else....that sort of thing, you'd use it if you had it.
 
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Dan Dubeau

Ultra Member
I agree 100% about not really caring about speed. Set it and forget it. Let it run overnight, as long as you're not dropping slugs, it'll be fine. If the wire breaks it will stop.

We'd all have multifix toolposts if we had WEDM :D. Mmmmm Dreamy.
 

kstrauss

Well-Known Member
Considering we're across the country a single shared machine wouldn't be reasonable. How about some of the electronics experts design/build a prototype pulse generator? There are many who could design/build the mechanical parts. Sort of a group build and rather like how 3d printers started. I'm certainly game to help.
 

Dan Dubeau

Ultra Member
I would gladly donate my mechanical/machining capability in exchange for the electrical portion. I think that idea has merit. If a design was made (and agreed upon), we could divide up the parts into small production runs each, and pool resources to build a bunch of machines.
 
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