Zeroing bit from roughing cut to finishing cut

[boxerstoo]

I am using a Cut3D file with a Rockler Shark CNC that has me change bits between Roughing and Finishing.
I need to know when I reference the Rough Cut bit and zero out, do I have to make sure the end of the Finishing Cut bit is exactly the same place as the Rough Cut bit?
Or do I reference the Finishing bit to the new level before I zero out?

[scottp55]

TRY to Z-Zero in the same EXACT spot as your roughing tool.
scott

[davemartin88]

On my Shark, if your 3D object isn't covering the entire material, I found it was best to set the Z on a point outside the cutting area. This lets you make tool changes that result in a consistent starting point for the first outing and finishing bits.