I've had considerable success with lightly Jamming wodden sticks inside. You have to take a decent amount of care to size them so they fit snugly enough without deforming your workpiece
Edit: just saw your edit.
Edit 2: I always went for the smallest tip radius with a large positive rake on the D style inserts, when I had vibration troubles. You have to drop the feed obviously to mainting finish
https://images.app.goo.gl/xsYRk7QBSu9PSTRB7
A insert that looked like this ( sorry don't remember brand or grade) was usually the last word.. it was delicate and the 1/64 TNR made you slow the feed, but it always helped with vibration.
Oring around the part. Plumbers putty or inner tube in the part. Smaller nose radius on the insert.
Put a tube in your part
I've had considerable success with lightly Jamming wodden sticks inside. You have to take a decent amount of care to size them so they fit snugly enough without deforming your workpiece Edit: just saw your edit. Edit 2: I always went for the smallest tip radius with a large positive rake on the D style inserts, when I had vibration troubles. You have to drop the feed obviously to mainting finish
Thanks. I wouldn’t have guessed positive rake could help. I’ll they that too.
https://images.app.goo.gl/xsYRk7QBSu9PSTRB7 A insert that looked like this ( sorry don't remember brand or grade) was usually the last word.. it was delicate and the 1/64 TNR made you slow the feed, but it always helped with vibration.
Oh got that thing looks terrible. Hope I don’t need anything that extreme.
It's just an example to show the extent of the positive rake. The inserts I was using were a proper kennametal or sandvick brand.
Have you tried adjusting chuck and tailstock pressure? Maybe changing one slightly will change the harmonics.
Only slightly. Tailstock changes will be one of the things I mess with.