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Help with an EDM machine

jddfuentes

Plastic
Joined
Apr 12, 2022
Hello! Greetings from Argentina.
I'm a student in Mechanics Engineering and I'm currently doing a internship at CNC Lab (the University has mill, lathe, EDM). I'm having some questions about a machine which model is SHENZHEN FIRST DK7740FZXM (it's rebranded but I figured out to find the real name). The questions are:

-Does this controller have a code similar to G00? In the manual doesn't say anything (only G01 moves) but the movement is very slow when it's not cutting (40 μm/s is configured because if it's faster than 60μm/s may break the wire)
-What kind of electrode uses this machine? I'm searching for a replace because the wire is cutting also the electrode and the manual doesn't say anything either.

I'm new in this forum and I'm sorry if I broke any rule.

Anyways, thanks for your time and I'm hoping for your answers.

Goodbye. Have a nice day.

Edit: I forgot to upload a picture of the electrode.

WhatsApp Image 2022-05-16 at 2.23.39 PM.jpg

And there is a picture of the machine itself

WhatsApp Image 2022-05-16 at 2.23.38 PM.jpg
 
Last edited:
Hi jdfuentes:
Your question doesn't give us much to work with but I will try anyway:

I am guessing from some of what you say that you have a wire EDM machine, not a sinker EDM machine...is that correct?
If that is true, you can use several kinds of electrode wire but the most common is hard brass wire, and the most common diameter is 0.25mm.
You need to know what wire guides you have...each size of wire needs the correct guides.

The traverse rate you are describing is typical for wire EDM machines when they are cutting 50 mm of steel...around 2.4 mm per minute.
Your rapid traverse rates (G00) should be around 500 times that so about 1200 mm per minute.
It is different for every machine, but these are common traverse rates.

Your G00 speed should be about the same as the speed when you jog an axis.
If your machine is a wire EDM Cutoff machine, then you will most likely be using a molybdenum wire, and I do not know what the rapid traverse speed should be or if the machine will even accept a G00 command.

Hopefully that is helpful.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining
 
Yes, correct, this machine uses a molybdenum wire. In the manual doesn't show anything about G00 command so I suppose it doesn't accept that command but the manual isn't very clear in some aspects, so I tried to asking here if someone knows about this machine.

I am not very good explaining but what I was trying to ask about the object is beneath the wire. I think it's an electrode just like some hand-drills or tools with graphite/carbon. I attach another pic of what I was trying to ask.

Anyways, thank you so much for your response and sorry for the mistakes I've made writing this haha.
 

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Hi again jddfuentes:
The wire is the electrode on a wire EDM machine.
Most use the wire only one time and then throw it away.
The newer wire EDM cutoff machines use the same wire over and over, running it from one spool to another and then back again.

The ones that use the wire only one time are much more accurate and can do many more things, some very sophisticated.
They use disposable brass wire partly to permit that super accuracy...so the wire is very round and very consistent in diameter...within microns.
But it is damaged as soon as it has been used, so it cannot be used again.

The cutoff machines use and re-use molybdenum wire and accept the loss of accuracy.
The wire eventually gets too weak to use and must also be replaced, but it will last a long time so these machines are much cheaper to use.
They can only do very limited things...mostly straight cuts so they are used for cutting hard or fragile material to length, to cut 3D metal printed parts from their build platforms and other similar tasks.

Cheers

Marcus
www.implant-mechanix.com
www.vancouverwireedm.com.
 
Thanks, I was looking for the carbide. In the manual in some "tiny letters", I found the carbide's type. It's a YG6 (FCC3), a tungsten carbide.

Thanks for your help, it was useful to learn new things about this machine!
Cheers.
 
Hi again jddfuentes:
The "carbide" you're referring to is a part that's most commonly called a "power contact" or some similar phrase in EDM language.
Its job is to transfer the electric current from the spark generator to the wire so the wire is energized and can cut.
On all of the wire EDM machines I am familiar with, there are two...an upper(above the workpiece) and a lower (below the workpiece).
These will contact the wire above and below the wire guides.
They are consumable parts...the sliding wire together with the electric current will wear grooves into the contacts until they don't touch the wire properly anymore.
Commonly they are moved to a different position (indexed) when that happens, and when all the usable surface is ruined, they are replaced with new ones.

Cheers

Marcus
www.implant-mechanix.com
www.vancouverwireedm.com
 








 
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