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Machine issues


Sep 8, 2021
Got a question I already know the answer to (i think?)

Running a Mazak QTN 260-II MY. Awesome machine, and probably the reason I now love Mazak. Started running it back in December after years of misuse from previous operators. Problems have been getting worse over time, and have reached absolute shit show levels within the past month.

So, multiple problems I'm having are the chuck will not hold a part properly. Anything over 1000 RPM, .01 IPR, and .05DOC will cause the part to be pushed back in the chuck, and will cause the jaws to start opening mid run. Tore the chuck apart, cleaned it out and noticed alot of bluing in the chuck body itself. Slapped it all back together, greased the absolute dog shit out of it, and it didn't fix it. Now, I have a good 1/16 of vertical play, and some decent wiggle from side to side, as well as some bulge(?) When it clamps. I've already brought this issue up to management, and they're response has been basically not their problem. Even when it has been brought up that it's a safety issue, and a part may end up going into low earth orbit. Now, im 100% sure the chuck needs to be replaced. Is there anything else that I could do to keep this from going to complete shit, or am I just gonna be in for a wild ride?
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That big round heavy thing is no longer a chuck. 1/16 wiggle is a useless worn out chuck. For fooks sake I have a 10" Kita that is 22 years old. Cannot feel any play. Grease it with JB Weld, should stop any wiggle. Just my opinion.
Crash the dog shit out of it and say a part came loose. You have to smuck it up enough that it must be replaced. Or just refuse to run it because it will eventually damage something or injure someone. A new 8 inch Kitigawa is only about 2800. Peanuts compared to how much damage a 3 lb piece of material can cause when ejected from the chuck at 3500 rpm. Believe me, I have seen it.