Peeps.
Having massive issues with chatter on our lathe.
Machine is Daewoo 10hc with 1600 hours on it. 10inch chuck. Material is mild steel
I have to back turn a bearing bore. I have done hundreds of these parts and have had various degrees of success over the years.
The back turning op some batches runs great. 44.25mm bore. 1000rpm .12mm/rev dcmt insert finisher. 0.5mm depth of cut
Holds great size good tip life. Nowdays I may run 10 parts then chatter turns up. Real bad chatter. Tune it out by dropping to 400rpm and .22mm/rev but surface finish suffers. New tips don't help 25mm boring bar sticking out 95mm. Have just gone up to a 32mm bar same stick out but chatter even worse. Down to 200rpm to tune it out.
I have pulled all my hair out trying to get this right.
Next step is to recut the soft jaws. If that doesn't help then I will put the boring bar on another tool station. If that doesn't work then I will put the job on another machine and try it.

Anything I may have missed?