Nomogram. To determine the RCF using a Nomogram, draw a straight line on the Nomogram connecting the known RPM (C) to the known rotor radius (A). The point where the straight line intersects the B scale is the approximate RCF.
Conversion Table. Draw a line from the known RPM to the column of the known rotor radius. Then draw a line from the known rotor radius to the line of the known RPM. Where the two intersect is the RCF.