Need ideas for EDM topic

Hi EDM'ers!

I need suggestions from this readership for an EDM-related topic for EDM TODAY magazine.

For 27 years, we have covered every aspect of EDM more than once - with updates, of course, but without being too redundant, I'd like some guidance on what you'd like to read about next. You can go into our archives to see past articles if it will give you ideas.

Thanking you in advance.

Bud Guitrau
EDM Today Magazine

Hi Bud!

How about an article about finding and calculating cutting conditions those venturing into the world of turn and burn?

That's a great idea Zahnrad Kopf; there's almost nothing out there of any technical value.

Bud, if you could focus your attention on "Spin-and-Burn" that would be a big bonus, because that's obviously the hard one from the POV of how to set up the cutting conditions.
I farted about for a long time before I got a notion of why it wasn't working for me; so I, for one, would love to get the benefit of your knowledge and experience.
Please also be sure to link to your article from a PM post; otherwise I'll forget to look for it when the time comes.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

implmex said:

That's a great idea Zahnrad Kopf; there's almost nothing out there of any technical value.

Bud, if you could focus your attention on "Spin-and-Burn" that would be a big bonus, because that's obviously the hard one from the POV of how to set up the cutting conditions.

Click to expand...

Thanks, Marcus. To be clear, your "Spin-and-Burn" is exactly what I meant by "Turn and Burn". I could have specified it a bit more clearly. The reason I asked for it is that I have faced the exact same issues - Absolutely ZERO for information, guidelines, or even starting guesses for how to start and what to consider.

For those not otherwise aware, the cutting conditions or wire speed all have to be adjusted a HUGE amount, oft to the point of being in completely uncharted or otherwise recorded waters. Suddenly, the part's spinning has a similar mandate to be considered in much the same way as turning on a lathe does, but now with the added restriction of figuring out how to adjust one's wire speed to deal with it. As well, actual cut conditions will be affected GREATLY as new material is being introduced rapidly and constantly as the part spins. It's not for the scheduled constrained to be experimenting with and has single-handedly been the benefactor of increased Scotch sales and consumption in this area of the country...

Frankly, you have gotten farther along than I have, I suspect. Bud should stop by your place and do a feature. Maybe with one of those large titanium cylindrical parts as an example piece? LOL! Okay... maybe not...

Hi again Zahnrad Kopf:
You wrote "Maybe with one of those large titanium cylindrical parts ".

I don't know; is EDM Today Magazine a family friendly publication???
(For those of you who have no idea what ZK and I are babbling about, I make a lot of parts for a high end sex shop and they are ...you guessed it...titanium and roughly cylindrical .)

Fortunately none of them are "Spin and Burn" parts so Bud, you're off the hook on that one and don't have to go there!

But if it will help you, I do have a few "turn-while-burn" parts and "index and burn" parts that I've taken photos of over the years.
You are most welcome to them if you want them for your article...just ask!

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

Hi Marcus and Zahnrad,

Thanks for your input and you are both correct; there is virtually no canned technology available for turn and burn applications.

I touched on this in "Turn and Burn Explained" in the Spring issue of 2013. After the rough cuts called "slabbing" are completed, there are no suggested settings from any OEM for rotary machining. This is because of the minuscule amount of surface area engaged compared to any straight-walled cut as shown in the diagram. Following the EDM rule of; "Area = Amperage", and with almost zero surface area engaged, this makes creating generator and servo settings a shot-in-the-dark.

If anyone has other suggestions or experience on the topic of "settings", I'll run with it if I can, but I suspect this aspect of turn and burn will be quite difficult to document and will probably remain a "cut and try" challenge.



With the picture in view, I'll use this opportunity to expand a bit upon the direction of rotation. In this example, CCW rotation will effectively decrease the actual wire speed, while CW rotation will effectively increase wire speed. This directional choice and the speed of part rotation will broaden your wire speed range without changing the true wire speed at the control. However, without doing a lot of math, recording the true wire speed for documentation (future settings) would be difficult.

Except for roughing, nothing about rotary machining is easy. Just ask anyone here who has already slogged through this the hard way. From those of you who have done it the hard way, I'd appreciate your guidance if this subject can be properly addressed. Personally, I suspect that this is probably too large a study for a periodical such as EDM Today. To give you an idea of how difficult this would be (and despite the small niche-market of rotary machining in EDM), there is no EDM builder (even with all of their knowledge and resources), who has developed (let alone published), this technology for their rotary-machining customers.

Which brings us back to the main reason for your suggestions, thanks.

Tough subject... anyone else?

Bud Guitrau

Bud Guitrau said:

Thanks for your input and you are both correct; there is virtually no canned technology available for turn and burn applications.

< SNIPPAGE >

If anyone has other suggestions or experience on the topic of "settings", I'll run with it if I can, but I suspect this aspect of turn and burn will be quite difficult to document and will probably remain a "cut and try" challenge.

Click to expand...

Bud,

I think it would be nearly impossible to address actual settings for cut conditions and other data, given the sheer multitude of machines and specific applications.

HOWEVER...

Where you might have some ground to anchor into is a detailed overview of the various considerations to be made, as well as some general guidelines for how to get to the matter of actually making such choices and decisions. Not unlike what you just posted, albeit a bit more comprehensively with possibly some guidance on just how those things will be affected so that Joe Burner can made some semi educated guesses at how to proceed.

For my own part, I figured out early on that full on roughing conditions were counter productive. As well, flushing concerns are abundant simply for the shape of the part and its ( usually ) counter optimal relationship to the nozzles and guides...

But wire speed and current amplitude and current density would be a great start! As in, comparing the spin and burn condition against that of static burning in both rough and finish conditions so that Joe Burner gets some manner of idea on how to possibly calculate the relationships for their own machines.

Maybe even how to diagnose a poorly performing spin and burn operation in effort to shed light on correcting or improving it... (?)

Hey Bud, that was a GREAT read; I got a ton of good stuff from that article!
Thanks very much for posting that link...you're the MAN!!

Regarding your comments on rotary wire work and its challenges; yeah I hear you, but the interesting thing is that the "simple" spin and burn" EDM turning is actually the most difficult by far as you alluded to in your article.
Much of what you write about came to me by trial and error and I came to pretty much the same conclusions you have.
I thought it was all some big secret because I could find nothing on the 'net about 10 years ago when I got my first wire with a rotary, and I have to confess I pretty much stopped looking after I participated in an article in Micro Machining that Al Richter wrote way back in 2011.
Here's a link if you're interested:
Rotary Burn: Rotary axis turns a wire EDM into a ‘lathe’ | MICROmanufacturing


So to move on back to your article; do you have a disciplined way you approach an EDM challenge where you are starting out from a position of "It's not frickin' WORKING!!!"
"Where do I start???"

I have a "mental map" that I follow because I confront this a lot, and that's because I take on all kinds of weird projects that cannot be cut conventionally so everyone turns it down and that's my opportunity.
Do you have a mental map of this sort too?
Kind of like "my wire's breaking, so do this first...look for that outcome, tweak this next" etc etc etc.
Would it make a good start point for an article?

It seems to me, that when posters on PM are asking questions about how to approach some EDM problem it's often for lack of such a mental map that they get stuck.
Modern machines and practices don't really encourage doodling about like this; much is canned that wasn't before.
I doubt all that many sinker guys listen for the sound of bacon frying anymore...they select an E Pack instead.
That only works when it works.
When it doesn't ...

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

Hey Zahnrad Kopf, you beat me to it again... you type faster than me!
MC

Bud Guitrau said:

Hi EDM'ers!

I need suggestions from this readership for an EDM-related topic for EDM TODAY magazine.

Click to expand...

Contemplating purchasing a Wire EDM machine - but EDM is new to me. I’m wondering if I should buy new or used - don’t know what age of machines are appropriate / cost effective for what I’m doing...

An article that discusses the timeline of EDM technology, when various innovations were added, how performance / cost has evolved, guides for what to expect from various era of machines, etc. would be very helpful.

Bud,

How about a basic... and I mean: VERY basic article on wire edm?

When I became interested in the process/industry, I literally scoured every possible source I could find, and found virtually nothing about wire edm. Simple questions like: "how does the process work?", or "how fast/slow is it?" were impossible to find plain English answers for. (for reference, this was early 2000's).

Then, by a total fluke I met "The Metal Doctor" (Marsh Syverson who was very active online in years after that). I drove to his shop in San Jose one weekend, and in a half a day I learned 100x as much as I'd been able to find in the past 6 months. (I was still only in the stage of deciding whether I wanted to purchase a machine).

I had a few pages of VERY basic information on my web site in the years when I was in the business, and I would point every customer who called me to get work done to those pages. My wire work was primarily prototypes and short-run work, and I'd say 95% of the people that called me for wire work had no idea how the process worked. Those few simple pages saved me a LOT of wasted time on the phone!

Of course times have changed, and there is a lot more information available online than there was 15+ years ago. However, I feel that simple, clear explanations of wire edm not only helps people that might be interested in getting into the business, but *absolutely* helps people that are either looking to get parts wire cut, or helps the people that may never even have considered wire edm as an alternative solution to a manufacturing problem they are having.

In my personal experience... there was a "threshold" that was crossed once I was a few years into the business... and at that point I was "off to the races", and resolving even the strangest of problems never seemed all that difficult or time consuming any more. I'm in no way saying that turn/burn or spin/burn is easy -- far from it. More information is always good! But I believe there is plenty to gain for the entire industry by writing articles for the absolute beginner, as well as for the potential customer of wire edm.

PM

Sinker EDM - when to use copper and when to use graphite electrodes. How to select graphite type.