my Axis is going crazy any assistance would be great

[kevtn]

So I am trying to do some coasters for a friend for his dad. but after 'two passes' the z axis tries to dig it's way to China. It is happening with every file I try. 

below are a couple of samples of what it is doing. 

well so much for uploading any pictures....I'm really trying to enjoy this purchase. 

[dadof4]

Totally isolate the wires to your Z axis from all other wires and see if that corrects the problem.