Just started out making my own automatic tool changer spindle, I have based it loosly on a scaled down version of commercial taper tooling, I have elected to use an 8.5deg taper with conventional pull stud design, I have just finished the main spindle component. The spindle will run in a pair of angular contact bearings at the nose and plain radial bearing at the top end, drive will be via the side of the main housing via a toothed belt driveleaving the top of the spindle assembly free for the pneumatic cylinder to release the taper tooling.