Thanks simpson.
It`still hard for me to understand it, but I have only read your last post 10 times :-)
The first line you wrote about starting at the bottom - is it something you do with the CAM software or Mach3? The Gcodes starts at the bottom or the tool is touching the bottom when it´s zeroed?
Because I think that if I set the Z zero at the bottom of my material, the machine wil try to mill my table. But it can`t - thanks to limit switches.
I think my coordinates are always positiv, but I didn`t play enough with different settings.
I don`t know how the professional Cam software works, but I`m using Meshcam. If I generate the Gcodes, I can save them one by one. f.ex. first Rough and then Finish. When the rough pass is over with an endmill I load the Finish pass Gcodes, but I need to change tool to a ballmill first. The "start point" for both passes is the same, but my ballmill is maybe longer then my endmill.
And because the top surface is milled away during the roughing pass, I can`t zero the ballmill. The ballmill needs to be zeroed on top of the material surface, which is gone.
Thats where I am now, but I need to try this Zero at the bottom next time.
Adam