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Help with wire breaking on round part

Jvizzi

Aluminum
Joined
Jun 15, 2011
Location
Florida
I'm new to Wire EDM and am having trouble with a roughing cut on this part. It is a lathe part that I am trying to cut a series of "U" shaped notches into a lathe turned part.

The cut is approaching perpendicularly to the axis of the part so engagement of the wire is very thin at the beginning of the cut, and gets thicker as it gets toward the middle of the part.

Under the current cut conditions, the wire broke almost immediately 3 times in a row.

This is on a Sodick ALN600G, .25mm brass wire

The material is Stavax with a diameter of 6.7mm

These are the conditions I was given by the controller:
(-----------ON--OFF---IP-HRP-MAO----SV---V---SF--C-PIK-CTRL--WK--WT--WS--WP---PC-----SK-----BSA);
C0001 = 0009 015 2215 000 271 +040.0 8.0 0037 0 000 0000 025 160 101 035 000000 000000 250099;

it seems like the varying thickness of the cut is what is causing the problem. I have a whole family of parts like this. Any recommendations?
 

JZ.

Aluminum
Joined
Sep 26, 2018
Location
pa usa
I'm new to Wire EDM and am having trouble with a roughing cut on this part. It is a lathe part that I am trying to cut a series of "U" shaped notches into a lathe turned part.

The cut is approaching perpendicularly to the axis of the part so engagement of the wire is very thin at the beginning of the cut, and gets thicker as it gets toward the middle of the part.

Under the current cut conditions, the wire broke almost immediately 3 times in a row.

This is on a Sodick ALN600G, .25mm brass wire

The material is Stavax with a diameter of 6.7mm

These are the conditions I was given by the controller:
(-----------ON--OFF---IP-HRP-MAO----SV---V---SF--C-PIK-CTRL--WK--WT--WS--WP---PC-----SK-----BSA);
C0001 = 0009 015 2215 000 271 +040.0 8.0 0037 0 000 0000 025 160 101 035 000000 000000 250099;

it seems like the varying thickness of the cut is what is causing the problem. I have a whole family of parts like this. Any recommendations?

So I am understanding this, you are cutting this on the face of the 6.7mm diameter? I have the same machine. Are those the conditions it's giving you? Probably poor flushing.
Try taking your MAO 282, go down to 0025 on SF and put your WP at 40. You have ALN so if your AUTO TC is active you can go that route or use the C555 condition and let machine do the thinking for you. You can also go -1 or -2 on your EPA for easy adjustment.
 

Jvizzi

Aluminum
Joined
Jun 15, 2011
Location
Florida
So I am understanding this, you are cutting this on the face of the 6.7mm diameter?

No, I am approaching perpendicular to the axis of the part, so the wire is beginning the cut at the tangency point of the outer diameter.
 

JZ.

Aluminum
Joined
Sep 26, 2018
Location
pa usa
No, I am approaching perpendicular to the axis of the part, so the wire is beginning the cut at the tangency point of the outer diameter.

Try slowing it down a little and more flushing. What are your guide positions and are you turning on High Pressure?
 

Jvizzi

Aluminum
Joined
Jun 15, 2011
Location
Florida
So after speaking with Sodick apps, I decided to just do some testing on a blank Ø.375 of the same material and just take a few slices off of it.

This cut was successful 2 times in a row:
C0001 = 0009 015 2215 000 261 +040.0 8.0 0031 0 000 0000 025 160 096 045 000000 000000 250000;

And this one failed like before, took about 5 break/re-tries to get thru:
C0001 = 0012 015 2215 000 251 +040.0 8.0 0047 0 000 0000 025 160 100 045 000000 000000 250115;

But I don't know enough to understand what was the biggest factor between them. I see the SF was the largest numerical difference.
 

Shane030173

Aluminum
Joined
May 21, 2013
Location
PA
So after speaking with Sodick apps, I decided to just do some testing on a blank Ø.375 of the same material and just take a few slices off of it.

This cut was successful 2 times in a row:
C0001 = 0009 015 2215 000 261 +040.0 8.0 0031 0 000 0000 025 160 096 045 000000 000000 250000;

And this one failed like before, took about 5 break/re-tries to get thru:
C0001 = 0012 015 2215 000 251 +040.0 8.0 0047 0 000 0000 025 160 100 045 000000 000000 250115;

But I don't know enough to understand what was the biggest factor between them. I see the SF was the largest numerical difference.


The successful header has a slower feedrate with less on time. Try changing your off time to 115. This will cut a little slower but will be a much more stable cut in open cutting conditions.
 

Jvizzi

Aluminum
Joined
Jun 15, 2011
Location
Florida
I ended up going with the first cut conditions with an edit to the SV of 50.0 and seems to be making it through all the cuts without any breaks
 

Luke.kerbey

Cast Iron
Joined
Mar 2, 2019
If I ever have a job that I really can’t cut, like a rusty lump or an 50mm cut at some ridiculous degrees. I use condition 0555. Cuts slow as hell but it will not break.

That really is a last resort but sometimes gets me out the shit.

What nozzles are you using? What flushing rate have you got? Is your part in supported or high from the deck?

I’m wondering if your part is vibrating slightly. I’ve had that before.
 








 
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