Here's how I use this technique and it's quick too. I set a carriage stop on my ways at the beginning point of the thread (in the gutter) and the carriage against the stop, then rotate the chuck by hand until a number lines up on the dial and engage the threading lever. At the end of a cut after disengaging the threading lever I back my cross feed out exactly 1 turn, return the carriage until against the stop, rotate the chuck by hand until that same number comes up on the dial and engage the threading lever, run the crossfeed back in exactly 1 turn (helps to set a zero on the dial), increase my depth of cut with the compound and start the lathe for the next cut. Easy peasy and no destroyed tools or anxiety over hitting the number.