The best way to set tool height is to take a narrow pc of thick lexan (.030) is good and GENTLY move the cutter against the com. See which way the lexan leans and go from there. I don't know which way your lathe goes but you can be "too far" off the way they tell you to be (above or below ctr) and it won't hurt anything. If you are off the other way the tool will drag instead of cut.
To see how this works take your tool and hold it against a tire as if you were cutting. Put it on ctr. (close is good) Notice how the tool cotacts the surface. Next, hold it way below. Notice how its going to try to cut with the wrog edge? Next, put it slightly above. See that with a properly sharpened tool how it cuts?If you have any questions you can e-mail rlj@nls,net