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how to erodate helix ?

NewToEDM

Plastic
Joined
Oct 26, 2018
I have an old sinking edm machine and i have to erodate with a cylinder shaped electrode in a helix pattern , is it possible ?
 
Hi NewToEDM:
When you say "I have an OLD sinking EDM" just how old are we talking about?
Is it a CNC sinker?
Does it have a C axis? (controlled electrode rotation on the ram).
Are you talking about following a helical path in Z to create a thread or a helical spline or do you want to make a bunch of holes around the periphery of a cylinder in a helical pattern?

All is possible, but depending on what you want and what you have, it can be complicated to do or very simple.
Easiest is with a CNC sinker that has a C axis, but you can do it even with an old hydraulic ram manual machine if you're willing to make special attachments for it.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining
 
Hi
Its a CNC machine , Exeron 312 from 2005.
I have a round electrode cylindrical shape with diameter of 40 , i have worked with it at 0 and at 180 degrees but i have some insertion in the part that are not eroded properly , and i was thinking that instead of working with electrode at various angles would be better to spin it , it would be one job.
 
If i would do a job on 3 axes and use the same X and Y and on C axis i start with 0 degrees at start Z and end with 360 degrees on end Z it would work ? Theoretical seems achievable.
 
Hi again NewToEDM:
It sounds from your description, like you want to make a cylindrical hole with a cylindrical electrode...is that correct?
It also sounds like you have a C axis on your machine.
So, if my understanding is correct, you want to spin the electrode one full rotation as it goes to depth to make your hole.

Why do you want to do that if your goal is simply to make a cylindrical hole?

You can just spin the electrode at say 100 RPM and then burn it down to depth while it's spinning.
You will get a better, rounder hole and it will flush better too, especially if you add some orbit in X and Y as you spin and burn.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining
 
Thank you Marcus , but i never worked a job like that. I will figure it out.

I am pretty sure that was obvious that i am not an english native speaker before you pointed this mistake, if you have time to spare you can check my other posts for more grammatical mistakes.Even so i will take it as a correction for improving my english language, thank you for that steve-l.


I have figure it out after i tested few times , i will check if it stays in tolerance when it spins.
Thank you :)
 
Last edited:
Hi again NewToEDM:
Don't apologize for your English...your English is at least as good as my German for sure, and with a bit of probing, I was able to understand what you meant.

Going back to your problem, you need to be able to make the C axis spin, and there will be a G code command to do that.
Then you need to be able to lower the ram and burn while keeping the C axis spinning.
That is a super common EDM function, so I cannot imagine that yours cannot do it...you just have to figure out how.
Third, if your machine supports it, figure out how to make X and Y orbit while all of the other motions are going on.
So the goal is to have the electrode spinning while the workpiece wobbles around the C axis by 0.15mm or so and burns downward in Z.
The wobble makes the gap between workpiece and electrode constantly change so it acts almost like a gear pump and will force the dirty dielectric oil out of the gap and bring in fresh dielectric oil.
That keeps the burn stable and avoids arcing.

The roundness of the result comes from the accuracy of the wobble, so the machine must be in good condition to get a nice round burn from an orbiting path with a spinning trode.
The spinning electrode distributes electrode wear so it averages out roundness errors in the trode and it enhances the pumping action.

So that's it...that's what you're trying to make the machine do.

Cheers

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








 
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