I wouldn't touch this job with a 10 foot pole!!! The only thing I've ever seen close to what you are proposing was done on a machine with a sub-spindle. The collet was left SLIGHTLY loose in the clamped position (more problems!) and the material was drawn out of the collet as the head moves in at the appropriate rate. Let me tell you honestly, this is a nightmare!!! This was a gov't job for feeder spindles in a 20mm gun feed system, and the spindles were only about 14 inches long. I can't imagine the headache on something 30 inches long with such a shallow taper and small diameter. Good Luck, I'll be watching this post also to see what other people come up with.