I needed an index wheel to flute some columns.  The index wheel is made from 3/4" phenolic covered plywood that is used in making concrete forms.   Using sharp point of dividers I scribed a 20", 18 1/5" and 16" circles.  Then 40, 24 and 10 points were located on the different scribed circles.  Using a 2 1/2" forester bit the recess for  washer was drilled and the 1 1/4" the center hole was drilled.   Wheel in locked to the spindle with the scroll chuck and the rope and stick exert enough holding pressure that the wheel can be turned by hand but it won't move when fluting the piece.