Actrually, the machine does the computations and crowning while the guitar is strung up to tension thus making the correct tweaks on the neck per the correct bow or imperfections under load. I've had three guitars done at Joe Glaser's shop ( He's the guy who worked with the inventor beta testing this original design and also helped Gibson set up their machines) here in NashVegas and they were as perfectly adjusted as I have ever experienced! Joe used me as one of his test monkey's because I use extremely low action (I've been the brunt of his jokes for many years!) to see if mine would play and sound accurately without buzzing or fretting out. In the beginning I worked with him back in forth to get a proper compound radius to my liking and the machine did a flawless job on a paticularly nasty ole 57' Strat that had alot humps and divots on the fretboard surface. The machine compensated for all the uneven spots and the fret dress was perfect! It's also very eye opening to see the computer graph of your baby before the work with all the heights of the frets shown in their worn and uneven glory! There is no way a human can do as a fret job this accurate and the minute you play it afterwards you will never go back!
