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914paul t1_isbs3cc wrote

Reply to comment by chocki305 in Trimming hardened linear shafts by Patex_

Totally agree. But if the shafts were 40mm, it would be money very well spent.

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chocki305 t1_isbssnn wrote

No it wouldn't.. as the cost of EDM would also go up.

You are ignoring a very important word.

precision

That is what an EDM does.

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914paul t1_isbwuyw wrote

Then I stand corrected.

Edit: I’ve had parts made by wire EDM (cutting dies), and had very high aspect ratio holes (50:1 or so) drilled by EDM. But never sinker, which is a truly fascinating process. You do any of that?

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chocki305 t1_isc4k75 wrote

I do wire EDM. As well as ProtoTrak milling. (ProtoTrak is kinda a half way between manual mill and CNC)

Sinker EDM functions on the same principle. And EDM drilling is just sinker with a round electrode. But allows for a smaller machine.

(all measurements are in imperial, as it is what I am use to)

Punch and dies are the bread and butter of EDM because of the level of precision. Normal machining, you deal with +/- .005.. good manual mill guys can hold .001. With an EDM you can hold .0001.

When I was taught, we made Punch and Die sets out of the same block using a very small wire .002 wire. One cut, and you have both parts ready to roll. But a pain in the ass to actually set up. As everything has to be perfectly straight.. as in less then a tenth of a thousands run out over 6 inches.

I would consider EDM way above any DIY work. It is akin to the posts you see on here where someone DIY a part using a half million dollar CNC mill with thousands of dollars in tooling. Nothing that I would expect from an at home DIY.

On average, I spend at least 30 minutes doing setup (mounting the part and stops on the machine table), and then another 30 minutes writing the program. So it feels like a big waste of time when the job is 1 part, and only takes 10 minutes to cut. But the customer pays for all that time.

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914paul t1_iscaegk wrote

Thanks for the thoughtful response. My original comment was really suggesting waterjet. Probably should have left the EDM out. I get the sense you feel your trade was undervalued - and that was not my intention at all. I have the highest respect.

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chocki305 t1_iscg1xj wrote

> I get the sense you feel your trade was undervalued

Not at all. It is more of a "right tool for the right job".. or as they say... application is everything. No sense using a highly precise cutting method when a saw will do.

My issues are more with this DIY sub then anything. I feel that many don't like a professional giving advice, or commenting on what is inaccurate.. despite many posts using professional equipment and then claiming it is DIY.

I wouldn't post what I do at work here, because it isn't fit for this sub. I am a professional using specialized tools and equipment. Despite me "doing it myself". But if I did an at home fix, where I didn't use my $100k+ machinery and tools, that would be fitting for this sub. And from what I have noticed, people want to make themselves look professional despite not being.. as if saying "yeah, I'm not a pro" is a bad thing.

Edit: I can honestly say our interaction.. has been the best I have had on this sub. I normally get a very negative reaction / attitude because I know what I am doing when it comes to metal work. I suck at wood, and am not afraid to admit it. I hope you have a wonderful weekend.

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914paul t1_isd8ope wrote

Have a great weekend. I’ll be trying to make a 6x8 array of very small holes in glass using hydrofluoric acid, 600 grit garnet, and gentle drilling. So…much cursing, probable lung damage, and quite possibly my garage declared uninhabitable. Hope you have something similarly fun planned!

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chocki305 t1_isdwl9k wrote

Oh my...

Stay safe, be careful.. I have used hydrochloric acid before. Lots of ventilation. Be careful with metals downwind.

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Patex_ OP t1_ise99rg wrote

Your comments have been appreciated. While EDM surely isn't applicable to my use case, I still pulled up google yesterday and learned something new about a topic I didn't even know existed :)

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