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Wire EDM Arcing Damage Examples

SMorris

Plastic
Joined
Nov 18, 2019
Hi,

I'm new to the forum so I hope I've posted this correctly.

I am trying to find some images / examples of uncontrolled arcing damage at electrical contact points that I can use as training material for Wire EDM visual inspection.

I've tried searching the internet but I'm not really finding much at all.

Does anyone have any pointers on where I could find this kind of information?

Many Thanks
 
Hi SMorris:
Are you looking for examples where a slug has touched a workpiece and burned a divot before it fell free?
Are you looking for instances where a fixture arced against a workpiece or against the machine table?
Are you looking for a gouge caused by the wire as a part fell free?

Whatever you're hoping for, I doubt you'll find many photos, so you'll likely have to engineer your own.
Do you have access to a machine?
Can you figure out a way to reliably create the problem you want to illustrate?
For showing slug scars and gouged parts, stacking thin plates and cutting simple shapes through the stack without clamping the parts will likely give you a few fucked up ones you can photograph.

To arc a workpiece against a fixture you might have to get a bit more creative, but I have created this problem for myself in the past by making the fixture too loose.
A good way might be to take some skinny hypodermic tubing, wire a slicing fixture for it deliberately too loose, and then bend the tubing a bit so the fixture will hold the whole tube but the individual slices will rattle when they are cut.
That ought to fuck up the individual bits pretty good, and it'll really show on the smooth surface of the tubing slices.

Cheers

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

Thank you very much for the reply.

I'm looking for arcing on the workpiece and also the fixture arcing on the workpiece as examples.

I am in agreement about it being difficult finding any photos, so yes we may have to engineer some, although this may be difficult as I guess the machines we have may have arc suppressing systems that may cut the machine out before arcing takes place.

Thanks again for your help
Steve
 
Hi,

That would be really helpful, I'm assuming that secondary EDM is arcing? As you can tell I'm not that experienced in EDM :)

Thanks
Steve
 
Hi,

That would be really helpful, I'm assuming that secondary EDM is arcing? As you can tell I'm not that experienced in EDM :)

Thanks
Steve
This is secondary edm from the part being able to move a little bit, it was a 50k thick shim. Corrected by adding set screws in strategic places to aid in holding.

KIMG0299.jpg
1574169543089142031745.jpg
 
Thank you very much for that.

I have a few questions:

Is the secondary EDM the pitting that is evident in the fixture channel?
Is this the same as uncontrolled arcing?
Am I ok to use this photograph in one of our procedures?

Thanks again
Steve
 
The pittingn is the secondary edm, it's caused when something is loose and causes it to create an arc between the grounded side and the work side.

It could be considered uncontrolled arcing.

Sure go ahead.
 
you wont find much because "uncontrolled arcing damage" leads to wire breakage and stops the process. It will create a line in your piece most likely and hardly a good representation of arcing damage. look to die sinking EDM better pictures!
 
Sinkers can really get damage when the flushing is too low, the dirty oil will become saturated with cuttings and burnt electrode and cause errant arcs.
 
coolest i ever saw was about a 3in tall .5 in "tornado" growing out of a cavity. pre cell phone day or y'all would see a picture!
 
Here is a picture of a Carbide Energizing Contact Plate and the Brass Energizing Block that are mating assemblies. Notice the extreme wear on both items from secondary discharging...this is the result of forgetting to lock down the Energizer Plate after indexing.

- BrianMVC-684F.jpg
 








 
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