Using the last wire on the reel....

Hi,
I am an inexperienced wire edm machine owner. Is it common to leave the last 1/5th of the wire on the reel and start a new one? I was given some reels of wire like this but find it problematic. The wire does not like to auto wire feed. I am thinking it has something to do with the smaller radius. Is this normal?

cheers,
James

It should be able to auto thread up until the last wrap comes off and tension cannot be sensed...what machine do you have?

It really depends on the machine's threader.
If the threading unit is just a simple cutter/threader, then the smaller spool dia will give problems.
OTOH if the threader has annealing - specially if programmable annealing even - then it should not pose a serious issue.

If I remember correctly, the Brother HS70 had a traveling annealer, where a powered carbide contact would move approx 8" up and down the wire to evenly anneal ( straighten )
the wire.
The Makino uses a mechanically simpler method with power contacts approx 12" apart and a stretch, but it only works if you use the Wire-Cut function to cut the wire.
The original Brother threader would anneal perhaps 2" or so of the wire and it was really unreliable.

With that said, how do you cut the wire manually?

A likely reason for the used rolls having 20% of the wire left on the spool could be the previous owner had a long running job that consumed 80% of the wire and he didn't want to run out of wire in the middle of a job.

Your 'short' ends should work fine; check all parts of the wire rethread system, something needs cleaning or replacing.

Hi James,

I can tell that depends on the threading system, in this case for Mitsubishi if the machine is well adjusted and in good conditions should be no problem, because when you change the spool must say to the machine which kind of wire it has and the weigh. Automatically machine shows the remain time in hours that wire has.

Best Regards.

Hi, I have a fanuc alpha-c400iB. Thanks! Definitely does not like the end of the reel..

FeinMecanix said:

Hi, I have a fanuc alpha-c400iB. Thanks! Definitely does not like the end of the reel..

Click to expand...

How are you cutting the wire manually?
My method is biting down on the end of the wire and gently holding the spool side between my palm as to not create a bend.
Then, using a cigarette lighter ( prefer Zippo as it always works ) move back and forth between my face and palm a few passes.
Then, hold the lighter a for a bit longer near my face and pull a bit harder until the wire breaks.

Result is an approx. 10" long dead straight wire with a bullet nose tip, absolutely no burr.

Works with all wires, even X-types.
Short of this, you will never thread a Brother machine.

Thanks for the great feedback guys!

cheers,
James

SeymourDumore said:

How are you cutting the wire manually?
My method is biting down on the end of the wire and gently holding the spool side between my palm as to not create a bend.
Then, using a cigarette lighter ( prefer Zippo as it always works ) move back and forth between my face and palm a few passes.
Then, hold the lighter a for a bit longer near my face and pull a bit harder until the wire breaks.

Result is an approx. 10" long dead straight wire with a bullet nose tip, absolutely no burr.

Works with all wires, even X-types.
Short of this, you will never thread a Brother machine.

Click to expand...

Yep, learned the lighter trick back in 1980 trying to rethread a 7 inch tall wind tunnel model.

"Never" is pretty strongly worded.

I normally keep everything "factory stock" on my wire EDM machines. The machines new from the factory
work really good. The one problem area that I found with the Brother wire EDMs was the power pin's contoured lead in.
That is why I make my own. By the hundreds! And they "very never" fail to autothread.
20 wire edms will go through a lot of power pins.

Regards,
John

Like Seymour said, zippo works best as it leaves both hands free.

As to leaving wire left on the reel, as others said, likely changed out before going home for the night to get more burn time.

Just remember that wire will go stale when/if you are trying to use up those old spools.

HS70A Brother said:

Yep, learned the lighter trick back in 1980 trying to rethread a 7 inch tall wind tunnel model.

"Never" is pretty strongly worded.

I normally keep everything "factory stock" on my wire EDM machines. The machines new from the factory
work really good. The one problem area that I found with the Brother wire EDMs was the power pin's contoured lead in.
That is why I make my own. By the hundreds! And they "very never" fail to autothread.
20 wire edms will go through a lot of power pins.

Regards,
John

Click to expand...

John, I don't know if the wire path on the 70A is different, but on the 3100 and 50A I have, the very first obstacle is the two Ruby wire cleaners before the upper head.
If your wire ain't straight, it ain't makin' it through. Period!
Then, you've got the upper wire guide, followed immediately by the lower wire guide.
None of them little b!tches will let anything through but a bullet nose wire. Scissors, sharp rolled cut, wire break etc ... Nope, it ain't goin' through!
Then you've got the turn roller, followed immediately by a ceramic guide and then the long, small dia steel tube.
If they are dead clean, they are nice.
Little debris on them: Better have a bullet tip or it ain't goin' through.
And, when the poor bastard does go through all of this, it now has the water/wire separator to deal with, sort of like the final challenge in a video game.
That wire - after all the hurdles of gettin' here - better still be straight AND have a nice bullet nose, else it isn't going through and it's Game Over!

Not joking, sometimes I doodle the Super Mario theme song while threading a not so pristine Brother.

The U3 Makino OTOH is amazingly forgiving for a wire tip condition.

Lol! Just heard super Mario brothers in my head!!!

FeinMecanix said:

Hi, I have a fanuc alpha-c400iB. Thanks! Definitely does not like the end of the reel..

Click to expand...

I've watch a factory demo of the fanuc wire. The operator was using 2 micron filters and every thing in the work tank was spotless.
The machine seemed to have a good wire annealer. You should be able to adjust yours for the type of wire you are using.
As others have said "keep things clean and repaired". Sonic cleaners work wonders for cleaning all those small parts.

Regards,
John