what would the offset be for a 6.35 mm diameter ball nose?

machine is off 1 cm in the z - axis when drilling. I.e. the drill is 1cm higher than it should be on z - axis.

I am trying to cut out cars for F-1 schools. The VR Milling 2D/3D simulation shows the car being cut out perfectly. There is also plenty of buffer room between the cut path and the metal fork/metal claw in the 2600 Router. However when I go to actually cut out the car with the 2600 Router. The tool ...