Hi All, thought I'd post some stuff about my Drill Mill conversion.
The machine turned out great and works as expected. Please feel free to ask me any questions about this machine as others were there to help along the way so I'm more than happy to reciprocate.

Some Specs:
Ball screws 16mm x 5mm pitch X and Y axis
Z axis has anti-backlash air ram with no springs. Works good.
Z axis 3:2 belt reduction
XY 2:1 belt reduction.
XYZ All DC servos from old robot.Sanyo Denki 75V
A axis closed loop stepper with 1000 PPR encoder
XYZ Drives are DGS4-8020 (DC servos)
A Axis leadshine (copy) closed loop stepper drive
NPN proximity switches on ALL 4 axis for limit and homing.
Power supply are 240VAC / 48 volt DC / 12 volt DC / 75 volt DC
Motion Control: Mach3 and USB Smooth Stepper
AUX: Coolant, Spindle control all via mach 2 control

See pics attached and also a short movie of the machine running on it first job. Paul CNC Drill Mill 10 2014 - YouTube