Quote Originally Posted by Davek0974 View Post
its not too bad at the low speed end but my spindle is a 24,000rpm water cooled job, my machine was built for aluminium really so it needs the speed. Looking at £1600-£2300 on Aliexpress :(
Then you are going to struggle as once you go bigger on diameter to take a QC taper the bearings needed won't hold up to 24K

If you can get away with just two tools, roughing and finishing then think about another 24K spindle mounted on another set of rails on the Z axis that can pneumatically push the second cutter down lower than the roughing cutter. Software then calls up the respective offsets and runs the second spindle.

You can get a completer second spindle and inverter for as low at £175 on Ebay.