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
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.