i am trying to cut a 4" radius with a .375 end mill, when i set the part up i can offset the work and cut what i need to, in order to get the job done but i don't want to keep working this way.  i am trying to cut a counter clockwise arc with the tool to the left of the cut. i will post the code tomorrow and maybe we can figure this out.

That would be a g3. g41 which would cut the inside of your 4" radius.

Ed

Search on the forum - Graham Waterworth gave a comprehensive explanation of tool cutter compensation no more than 1 month ago which explained which code to use depending on your direction and left or right compensation.