z axis shoots up at start of operations. G43? G54?

[benjaminsettili]

Good morning, 

I'm very new to CNC and I have a problem. In the beginning of my Gcode my CNC wants to drive the Z axis into heaven. I'm using Fusion 360 with the Stepcraft UCCNC Postprozessor and UCCNC. My CNC is a Stepcraft M.1000. If you have any idea where this problem comes from, I would be very happy about your help. 

Thank you

Benni

[seth.madore]

It's the G53 Z0. line of code, that is telling it to "Go Home" in the Z. If you don't have limit switches, it's going to behave exactly as you are seeing.

What you want to do is change your Post settings, changing your "Safe Retracts" to "Clearance Height".

Do be aware though, you will need to ensure that your cutting tool is ABOVE the surface of your stock, otherwise the tool will just gouge across the face.