Quote Originally Posted by bluesking View Post
I spent some time with a local CNC machine today which was using the Kress 1050 spindle - air cooled. Whilst not particularly loud (certainly compared to a router) it could certainly have been quieter.
Don't worry about the noise generated by air cooled spindles. It only makes a difference if you will be cutting air. ...and you'll be surprised how quiet an air cooled brushless spindle is compared to the Kress or a router...

I have been using air cooled spindle for some years now, though it is only 1.5kW, but it is that noisy before cutting starts. If it must be replaced I'll buy another air cooled spindle, that's for sure.