Here's the math behind compensating for the radius on the end of the toolbit,
r represents the radius of the toolbit. Given r and the angle (30 degrees) we
know that sin(30) = r / h. So h = r / sin( 30 ). What we really want is c,
which is amount that we need to compensate for when using a radiused toolbit
versus a sharp pointed toolbit.
c = h  r = r / sin(30)  r = r / 0.5  r = 2r  r = r.
That was a lot of work to come up with a simple answer.
Smaller...
