Edm breaks wire

[Mark32]

Hello
I am working on a Brother HS-70Am bought at auction.
The wire feeds alright and the machine homes. I have been trying to use the programs in memory. As they likely have worked in the past.
I start the program and the water flows in and the wire starts feeding. I have a small piece of metal 1/16 or 1/8 strapped down.
the wire contacts the material and breaks. I see a small arc. I have tried adjusting feed and current to no avail.
I need to know what i am doing wrong. Or what is causing the break. Not enough power to cut? tension to tight?
I am hoping somebody sees this and can point me in the proper direction to get this machine started. Or point me in the direction of what needs to be fixed so i can go after that.
2nd question and not as important as the first. Communication. Has anybody attached a floppy to the machine successfully. I tried connecting a floppy emulator directly to the floppy port on the computer with no success. I tried to access the bios again with no success.
I did manage to get a usb floppy to work to a point. IE it will transfer but I cannot format and it doesnt like to finish so will hang. But it did transfer. Has anybody had better success than me. As you might know there is no support for these machine from brother which really sucks.
Thank you
Mark

 

[nlancaster]

There are lots of things it could be, program written for a different wire or thicker part.
I would suggest reading this book, as it gave me a huge hand in learning to run the Wire EDMs when i started 5 years ago.
It is not a cheap book, but it has huge amounts of helpful information.

Amazon.com

From my expierence going from thick to thin parts, I think you have too much ON time compared to your OFF time for the wire and power levels you are running.
On my Sodick EDMs I run stacks of parts and at times I have to vastly lower the ON time to cut only 1 part with the same program.

EDIT: Also another great source of information, EDM Today magazine. I have read most of the articles on running wire EDM several times and every now and then something I read helps me run our Wire EDM machines. And best of all the magazine and the digital copies are free!

https://www.edmtodaymagazine.com/edm-today-issue-archives/

 

[machineit2]

There are lots of things it could be, program written for a different wire or thicker part.
I would suggest reading this book, as it gave me a huge hand in learning to run the Wire EDMs when i started 5 years ago.
It is not a cheap book, but it has huge amounts of helpful information.

Amazon.com

From my expierence going from thick to thin parts, I think you have too much ON time compared to your OFF time for the wire and power levels you are running.
On my Sodick EDMs I run stacks of parts and at times I have to vastly lower the ON time to cut only 1 part with the same program.

EDIT: Also another great source of information, EDM Today magazine. I have read most of the articles on running wire EDM several times and every now and then something I read helps me run our Wire EDM machines. And best of all the magazine and the digital copies are free!

https://www.edmtodaymagazine.com/edm-today-issue-archives/

 

[machineit2]

Picture above is what I have set to do nearly 2 inch tall SS pieces.

Mike

 

[SteveEx30]

My first thought was program made made for much thicker part.

Also your not sure if your workpiece is 1/16 or 1/8 which is odd. Is it a clean pc of material or an old rusty washer you found on the floor...

 

[nlancaster]

Picture above is what I have set to do nearly 2 inch tall SS pieces.

Mike

Mike,
Sadly I don't run Brother Wire EDMs so I am not sure what that screen is telling us.
I was just giving some general information based on my experience with my Sodick machines and lots of reading.

Another thing I thought of, how is the resistivity of your water?

 

[bob]

How far away from the part before it starts to cut? My antique will do that if I am less than atleast 20 thou away.

 

[Mark32]

Thank you all for the replies. The piece I am trying to cut is a piece of clean scrap not rusty. At the time I was writing I was not in front of the machine so didnt remember how thick the part was.

 

[Mark32]

I am clear enough that it spins some wire through before it hits say 15 to 30 seconds maybe more.

 

[plastikdreams]

What's your programmed feed?

 

[PPE]

Hello
I am working on a Brother HS-70Am bought at auction.
The wire feeds alright and the machine homes. I have been trying to use the programs in memory. As they likely have worked in the past.
I start the program and the water flows in and the wire starts feeding. I have a small piece of metal 1/16 or 1/8 strapped down.
the wire contacts the material and breaks. I see a small arc. I have tried adjusting feed and current to no avail.
I need to know what i am doing wrong. Or what is causing the break. Not enough power to cut? tension to tight?
I am hoping somebody sees this and can point me in the proper direction to get this machine started. Or point me in the direction of what needs to be fixed so i can go after that.
2nd question and not as important as the first. Communication. Has anybody attached a floppy to the machine successfully. I tried connecting a floppy emulator directly to the floppy port on the computer with no success. I tried to access the bios again with no success.
I did manage to get a usb floppy to work to a point. IE it will transfer but I cannot format and it doesnt like to finish so will hang. But it did transfer. Has anybody had better success than me. As you might know there is no support for these machine from brother which really sucks.
Thank you
Mark

Hi Mark,
I use an HS-70A (and HS-3100) on a regular basis and agree it sucks there is no support. Several things can be causing the wire breaks as you know. We generally use .25mm Gamma Plus brand coated wire, and hard wire for some applications. What are you using? Check your water conductivity as well. I attached a picture of a few of our user tech settings in that range so you can compare.

As for the communications, I usually hand type my programs but use a communications program to backup everything to a laptop. I have the Brother Comm program running on a windows 7 virtual machine and connect to the machine with an RS-232 to USB cable. I tried connecting with Bobcad in the past, but it just never worked for me. I have procedures with screenshots written up as well (in word). Not sure if I can post them here.

Scott

 

[Steve9]

I bought an HS 70 new from Charmilles in '05
Lucky it's fairly reliable as it has been orphaned by both Charmilles and Brother. Yeh....I won't start

If the contacts, one upper and one lower are worn it WILL NOT CUT. Wire breaks. These are wear items.
I get about 100 hours per side. They have four sides, just turn them.
These are small carbide pc held by two screws-speaking of screws I was trying to source/price the two lower ground cables. They are just 30" of 6ga cable kinda like the battery cables on a small car. One flat connecter with 1/4" hole on one side the other side is some proprietary connecter that goes in the lower arm.
$380/$550 EACH were the prices that I got.

If anyone knows of a good service person near S FL I would be grateful.

Steve