Allow entering V-bit as degrees + length

[jcoffland]

I have noticed when I wish to input a V Bit into OpenScam that I have to enter the length of the width and length of the cutting bit.
In a perfect world I'd love to simply enter in
"90 Degree Conical Cutter .125" shank"

[jcoffland]

In the meantime, given the tool diameter in either inches or mm and the tool angle in degrees, you can calculate the length of the cutting part of the tool as follows:

length = (diameter * tan((180 - angle) / 2)) / 2

E.g. if the tool diameter is 12.7mm and the angle is 60 degrees then:

length = (12.7mm * tan((180 - 60) / 2)) / 2 ~= 11mm

Make sure you calculator is in degrees mode not radians!