[Frogblender]

its probably a bad idea in the long term. the spindle uses roller bearings, which typically dont like high speed.

if you pulled the lower bearing and replaced it with a decent quality AC bearing, it might hold up much better at that speed.

youll also need to make sure you have a good belt and balanced pulleys or youll find the BELT heating up and failing. the smaller the pulley on the spindle shaft the better.

Aye, I think I'll put the 9K rpm on hold for a bit; I have a spare spindle which I might try to rebuild with better bearings.

Also still struggling with runout - at the tip of the tool it can be up to .001". Which is not good when trying to run a 2-flute at a chipload of .001" per tooth. I'm considering an on-the-mill R8 spindle grinding operation....

[ihavenofish]

Aye, I think I'll put the 9K rpm on hold for a bit; I have a spare spindle which I might try to rebuild with better bearings.

Also still struggling with runout - at the tip of the tool it can be up to .001". Which is not good when trying to run a 2-flute at a chipload of .001" per tooth. I'm considering an on-the-mill R8 spindle grinding operation....

the runout on my nm145 spindle is unmeasurable.

the runout on my COLLETS, well thats a different subject

so make sure you figure out what the actual source of runout is or youll be chasing your tail.

cheap r8 collets and ER chucks/collets can be terrible and often have burrs. also any dirt on the collet or taper can throw out a long tool by a large amount.