wow, here i am again requesting help. atached is my xlm file,   i think i had a brown out or automatic windows update.  i have been fiddeling with this for days. i do have  it working but things are off. x and y are ok except for shuttering in the curves even at low speeds.  the z way off!  i have been through the docs several times. and looked at many forum threads. it must be in the ball screw setup ?   don't know how it would have changed?  i think i have a standard acme screw 10" long .75 in diameter 9 tpi. direct drive to the servo.  also when i press the stop button, the bit does not raise, it stays in the work.  i think i have looked and changed everything.  what the heck am i missing.  thank you.  tony in indianapolis, indiana usa