Just wanted to clarify a little on clearance plane , rapid plane , feed plane , and top of part .

The clearance plane should always be higher than your rapid plane . This is an initial move at the start of a program and also between features .

The rapid plane is the lift used during the feature for rapid movements .

The feed plane should always be a positive number . This doesn't matter if the top of part is a positive or negative value .this is a distance to the top of cutting that the tool will start to feed .


The top of part should be the distance from were you touch off your tools to the top of the surface you are cutting. this could be a positive or negative value.
If you are trying to cut down in an area that is already cleared . Then your top of part will be a minus value from were you touched your tools.


Example :

If I have a part that I touched my tools off on the top of my part and zeroed them there, and there was a pocket already cut in it to 1/2" deep .
I want to cut a smaller pocket down in there that goes another 1/4" deep.

Then my top of part would be -0.5 , clearance plane could be 1.0 , rapid plane if I wanted to come out of the pocket would be .6 to get .1 above part for rapid moves.
and feed plane could be maybe .05 to start the feed just before cutting into the material.


Hope this helps.

MikeG