Spindle plunges through material at start of program

[Killerpiraat]

Hello, seems like more people have this problem. But im wondering if this happenes due to Mach3 or its a problem in the G-code.

This started to happen to me last week. The spindle plunges into my workpiece, before starting what it should do. I have a feeling it has to do something with this:

But this never happened to me before. It always worked good.
But even if a zero the Z axis, it still wants to another Z axis position way below the Z0 i just set.
I checked out some G-code from the past, (when it worked good), and they all have this piece of line where it goes to z0.

So what has changed? Why is my spindle moving so far down at the beginning of the program?

[engineguy]

@Killerpiraat 

That is your CNC Machine Z Zero that you should set by jogging your CNC Machine to a safe location, usually with the X and Y at for example the lower Left corner of it`s travel and the Z axis at it`s highest point or what you consider a safe height, maybe say 6in/150mm, depending on your CNC Machine Z available travel.

The line of code that you refer to will move your CNC Machine to those coordinates where it is out of the way and can also more easily facilitate Manual Tool Changes.

So, it is down to the way that you are using your CNC Machine, you must have changed your CNC Machine Z0 at some point so  that it is going to the Table Z0 height or the Part Z0 height instead of the "safe" Z height.

It is nothing to do with either Fusion or Mach3, they appear to be both working correctly.