Diameter of inside cut, too small

[SVM]

Kiwi,

Man you are good!

You know .. thinking about the distortion of the resulting arc if I enlarge the profile diameter, and the fact that it is mainly the 1st cusp on each side that causes the problem, it might be better to create a toolpath which has a finer stepover near the rim and thereby knocking out the 2 offending cusps.
I'll have to code that by combining 2 files. I'll try that today and see how well that fits.

Thanks for the effort!!

Btw, I'll be passing through NZ in October and again in December.

Rgds
Steen

[Kiwi]

Steen
Making smaller step-overs at the top will make a truer shape.
This is how I calculated only the cusp at the top of the curve.
I used a different formula for the cusps that were not trimmed with the parallel part of the ball nose cutter.

The dimensions maked are all known.
L1 = Sqr(5^2 - 4^2)
L2 = Sqr(L1^2 + (45+4)^2)
L3 (Cusp Height) = (100/2) - L2

Cheers.

[SVM]

Kiwi,

Ah ... pretty simple when you think about it. Thanks for the illustration and the explanation!

Thanks
Steen

[Kiwi]

Steen
This is how I calculated the other cusp heights....a bit more involved.

The dimensions maked are all known.
L1 = (100/2) - 15
A1 = ASin(L1) * 45
L2 = (100/2) - 17
A2 = ASin(L2) * 45
A3 = (A1 + A2) / 2
A4 = A3 - A1
A5 = (45 * Sin(A4)) / 5
A6 = 180 - A4 - A5
L3 = (5 * Sin(A6)) / Sin(A4)
L4 (Cusp Height) = (100/2) - L3

[SVM]

Kiwi,

Certainly a bit more involved, but still fairly straight forward geometry. I see what you are doing and kick myself for not thinking through the problem before asking :-)

Thanks again!

Steen