I have completed a Direction vector interactive calculator as an Excel spreadsheet. All you need to do is enter the number of points you wish to use for your circle measurement and hit enter. The spreadsheet lists the angle of each arc-to movement along with the I-J-K and L-M-N vector of each Go-meas point for the circle. It is great for gear shaped parts. If you would like a copy, e-mail me rcmetrology@yahoo.com, I'd like your feedback on it.