Wire breaking on mitsubishi FX10K

Hello,
We recently got a Mitsubishi FX10K and I have no experience with wire EDM at all. I got the machine up and running and software loaded etc. and got it to do a few test cuts. It seemed to be working ok. But now no matter what I do it breaks the wire after cutting a short distance. The wire is not breaking in the part but in the lower wire guide. I keep trying different epacks but nothing works. Does it sound like a need new wire guides. Any suggestions would be appreciated.

Dave

First thing I would look at if it was me, the lower roller ,check those bearings then the pinch rollers in the back ,check for wear and bearings .if you can check the tension of your wire and a good ultrasonic cleaning of the guides may even help.
Hope this helps
Paul

Are you using the right e pack from the manual for the thickness and material type of the part ? Are there any voids in the part and do you have the flush cups within a few thousandths of the top and bottom of the part? If those conditions are met(meaning you have good flush conditions) then I agree with Dave.

Thanks for the replies. I'm going check all of the suggestions.

Dave

This is probably resolved but try indexing your power feeders as well, they are the carbide inserts that energize the wire. They need indexed around every 80 hours of machining time. There will be an upper and lower one. When they are ready to index I always pull a scale out and slide them over about .06 or so from the previous position after cleaning them.

Another suggestion incase someone else needs help with this is to check the WT on your monitor for the epac you are using. If is to be cutting into the part, make sure it is on an EPAC# ending in 1 and that you have set the PM cut type to the right setting. (I usually have it set to Varying Condition). You can do this from the Monitor screen that you start the program in. If you are taking a good size cut and you are using say a E1002, E1003, or E1004 EPAC it needs a lot more power than these settings are set to. Also with your rough cuts, the feed rate is very low depending on the thickness and type of material. When in doubt I will set it to F.04 to be safe and then adjust it. On tall parts I have gone as slow as F.008 at times.

**If by chance there is either some kind of coating on the material, it happens to be CAST, it will break wire. You must remove heavy rust as well before trying to cut.** (I learned the hard way and was pulling my hair out).

Hope this helps,
Tvalen1432