in calculating the tool path

[Grumpy Mike]

Thanks routercnc, that is in essence what the solution posted by irving actually is, only the equations have been bashed about already to give the solution. The only difference being that instead of using:-
The equation for a circle (x^2 + y^2 = r^2)
then you use the parametric equation for a circle of :-
x = r SIN(theta)
y = r COS(theta)

[Wobblybootie]

Well, my contribution to this thread will be about as much use as tits on a kipper.

Reading it has seriously damaged my belief that I will ever master the maths involved in rudimentary CNC :sad:. I am beginning to think I should have listened to my old teacher instead of getting stuck into some practical human biology!!

Panic stricken in darkest Dorset!!