Z Axis Mechanical Layout Options - Bridgeport M Head

Well, I got my new (to me!) BP M head mill. I have already started
taking it apart for the clean up, ball screws, etc. One of the
things I have not resolved is the best way to accomodate the Z axis
travel. I am hoping someone can shed some light on the best way to
accomplish this.

If I move the quil, it appears there are a couple ways to do this.
1) mount a motor to turn the same shaft as the hand lever. This to
me has a problem of very long travel for a given rotational travel of
the motor, unless I severly under drive the pulley which still might
not be enough?
2) mount a motor to turn the fine feed shaft and worm gear. This
would fix the long travel per motor rotaion in 1 but the worm gear
isn't fixed to the shaft, it works on friction. I could key-way the
worm gear onto the shaft? This, to me, seems like the best approach
for moving the quil.

If I move the knee I would need a bigger motor and could still under
drive to address the higher torque required. However, there doesn't
appear to be any good mounting locations for this method.

Can anybody shed some light on this? I know people have done this
many times and would love to hear some insight. Thanks a bunch.

Mark
mark@...
www.mark.hargett.com