I run a VMC with a Meldas 520 controller. The way I activate cutter comp is I call out G41 Dxx in between the height plane (rapid plane) and the first 'Z' move into the part. In other words, you need to use the G41 (for climb cutting) and a D for the tool you are using. EX. G41 D07. Now in the tool length offset page there is a column that is labeled wear. In this column, the cutter comp will be entered as a negative for the appropriate tool. EX. -.005. This will add a total of .010" of cutter comp. I hope this helps you. Shane.