"Doctor, I have a pain, what could be wrong with me?"
"a pimple or cancer, take your pick"


* What's the machine,
* how is the z-axis driven (e.g. belt/pulley sizes, ballscrew/pitch, leadscrew/pitch?),
* what is the z-axis motor (NEMA size, torque, current rating.)
* what voltage/driver board/PSU
* What velocity/acceleration (original/new)
* what's the weight of the two spindles
* anything else that might be relevant