Tool rep told me to stop blaming the machine, he was right
Honestly, I spent months fighting chatter on a 5-axis job in Toledo, kept tweaking feeds and speeds. A tool rep watched one cycle and said my workholding was flexing, not the spindle. I switched to a dedicated fixture block and the finish went from 63 to 12 microinch, no program change. Anyone else had a rep catch something your gut kept missing?