Disable probe on plasmac

hi all 
im new here and i'm currently in school (mechanical engineering), we're making an plasma table for this semester project. as of right now we're almost done and during some test on it tho we cant figure out how to disable the probe when we start an test, we have made our setup so that it hits the material on the table and makes that the home, and then in the materials we have told it what hights it should cut it, so we dont need the probe, also atm. we dont have the waterbed on the table yet so we're trying to make the test up in the air.