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Charmilles E10-Isopulse P25 sinker EDM basics

Borealis

Aluminum
Joined
Jul 22, 2021
We took on a prototyping project involving some small punch-press dies. The female dies are roughly 1/4" across and have some small-radius internal corners. Because this is a short-term project and die-making isn't our bread-and-butter, I bought a mid-80s Charmilles E10. It's in beautiful condition and I've run a number of test burns with graphite electodes in A2 and O1. That said, I'm sure there's room for improvement. The max burn depth on these dies is less than 1/8".

The Charmilles factory manual contains almost no information about the Isopulse P25 generator settings and tradeoffs. I've found little information so far that pertains to 1980s-vintage sinker technology. A friend in LA said EDM in the 80s was a black art.

A few questions:
1. What drives the decision whether to run electrode-positive/part-negative, or vice versa?

2. How should the settings generally change as you go from roughing to finishing?

3. Any general advice?
 
You will want to be in positive for what your doing.

Oldschool hydraulic ram sinkers are a great way to learn EDM. Hopefully your shop is quiet because the best way to dial in that machine is just by listening to how its burning, and watching your readout for a steady drop....

Never ran that specific machine but generally speaking you dial down your IP (power) and ON as you approach your finish depth. Off times to adjust steady...

The last .005" should be powering down to improve the finish.
 
Do you have the manual “Practical Guide to EDM”? Lots of info but pretty technical.
Bob
 

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We took on a prototyping project involving some small punch-press dies. The female dies are roughly 1/4" across and have some small-radius internal corners. Because this is a short-term project and die-making isn't our bread-and-butter, I bought a mid-80s Charmilles E10. It's in beautiful condition and I've run a number of test burns with graphite electodes in A2 and O1. That said, I'm sure there's room for improvement. The max burn depth on these dies is less than 1/8".

The Charmilles factory manual contains almost no information about the Isopulse P25 generator settings and tradeoffs. I've found little information so far that pertains to 1980s-vintage sinker technology. A friend in LA said EDM in the 80s was a black art.

A few questions:
1. What drives the decision whether to run electrode-positive/part-negative, or vice versa?

2. How should the settings generally change as you go from roughing to finishing?

3. Any general advice?

Yo, I can`t say much as of now, it`s a bit too late and i`m a bit too lubed up to waddle two flights of stairs to my shop and check out my books, but i may have some Charmilles Isopulse texts... I give 0 guarantee, but i too snagged a gorgeous Charmilles EDM sinker from the good old days... She came with a major collection of Charmilles literature, now, i think it was mostly french, but what with modern picture to text translator apps, i`m sure you will manage... At any rate, electricity on EDM is pretty much similar to TIG settings... At least that`s how i perceive it...
Regarding polarity, it really works both ways, but it`s largely dependent on expertise or experience better said... I have 0, but i have years of tech study so i have some theoretical knowledge... To put it shortly, EDM sinker electrode polarity affects the speed of the burn/wear rate of the electrode... In case of positive electrode setup - the electrode wear slower and more even, however the burn takes longer, whereas the electrode negative setup burns faster but it burns the electrode faster aswell...
As the fine gentleman above me said, old school edm sinkers are an art, and as with tig, just listening to the arc or the burn can tell you all you need to know... You will quickly pick up how to fine tune your arc length or burn radius/depth by just sinking some copper pipe(thin copper pipes are the best drilling electrode, especially if you can plumb oil through them) into steel and using gauge pins to check exactly what the machine is doing at which setting, and you can fine tune it from there...
Regarding those potential texts, i really can`t vouch for them, i snagged the machine, unloaded everything at my shop, crammed it like a sardine can and ever since i have not really done anything with any of my machines... Gotta build a new shop, for now i just slather oil all over the beauties every so often and leave them be in peace... My machine is Charmilles D1T and the power module is Isopulse P3, but regardless of the machine and module itself, sinker settings are electricity, so as with tig, any machine does the same with same set-up in same material...


All the best and kind regards!
 








 
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