need help with my bridgeport series one . i am useing a 1/8 th inch carbide end mill running it at 6 inchs a minute at .034 a pass with flood coolant. i just installed a new hybrid nema 42 motor for the y axis, table is running smooth. but the spindle motor is still running rough. i replaced the timen belt and at 3000 rpms it runs good but still breaking tools. i am breaking the head down tomorrow for the 3rd time and going to put some plastic spacers in the varible speed pully.

thanks alex