The Web Machinist Manual Machine Calculators include a Lathe Cross Slide Calculator
where you can calculate the actual infeed of the cross slide when positioned at an
angle to the work piece. There also is a Lathe Tailstock Offset Calculator to calculate
how much live center offset you need in order to manually turn a taper or angle on
a lathe part. The Hex Pocket Endmill Calculator calculates the interior corners
of a hex based on the tool diameter.