Mits fx20k wire "backing up" in upper head

I started having problems last Monday with what I thought was the wire breaking. I went through all the normal maintenance, power feeders,cleaning every thing. Then the wire started "backing up in the upper unit. I was trying to cut Friday and it would run for a few minutes and I'd here a pop coming what it sounded like the back by the chopper. I took the plastic cover of the upper unit to watch what was happening. It would run for a few minutes, I'd hear this odd pop, and the wire would stop feeding and backup, or bunch up in the area of the pipe. Its not breaking the wire. The only thought I have is the bearing in the lower unit in the ceramic wheel or the rubber wheels in the back at the chopper. Those back rubber wheels that grip the wire do have a groove in them use over the years. One more thing. When it backs up in the top I can raise the head, hit the wire collect button, and manual feed and it will pull it through and make that sound that they do after threading is complete to the chopper and try and cut. It just does it again.


Hope this is not to wordy but I didn't want to leave out any information.

Thanx much for your help

Steve

I have a few preliminary questions.
How many hours since you rotated or replaced the chopper? We usually get a 1000 hrs out of one side (2000 per chopper).
Is the Chopper "locked up" when you remove it? This is usually a dull chopper.
I believe that you can rotate those rubber wheels in front of the chopper. I think the groove is "off center".

I just rotated the chopper when this problem first happened. I was able to cut. then the next day i did it again. How do you get those rubber wheels off? Looks like it takes a gear puller. I thought that minute groove was worn into the wheels and that the groove might be the problem. It shows in the manual that they can be removed and rotated just doesn't say how.

Here's some more info. That noise I'm hearing is not coming from the chopper. My next guess would be the control cabinet. maybe opening or closing. I sat in back while the wire was feeding and not cutting for about 5 min. nothing happened. so I started the program and returned to the chopper. when the wire made contact with the material to begin cutting I heard that pop noise and the machine shut down. BTW nothing shows on the af maintainence screen like when the wire breaks


Maybe it is an electrical problem. bout to pull my hair out

Does it sound like a wire break because it is pulling against an opposing force. In other words, is something locking up and the wire is getting torn loose?

Is it an electrical pop like something is grounded?

Will it run out in the open air without cutting anything?

The wire is not breaking it stops stops advancing and backs up in the area of the upper head that contains the pipe. yes it will run when not in contact with material. I cant come up with a way to describe the sound but its not a spark or the like. almost like a deep sound of a circuit breaker tripping.

What size wire are you using?

.01 standard brass

Please check if the tensile strength is 900n, i have seen this problem mainly with .008 wire and sometimes 500n .01 wire.

I had the same problem on our FX-10, I cleaned and flipped the take up rollers and changed the bearings and it has'nt done it since.