Curve, major/Minor Ø

[[Cl...]]

I have an ID hexalobe (six sided star). I need the major, and minor diameters. Usually I scan a 2d curve around the star ID, and use 3 "minimum points" & 3 "maximum points" from the curve to create the circles. This method is working for the major Ø, but not the minor Ø. I have 4 secondary alignments at 30°/60°/120°150° choosing the Y axis, (Base Alignment 0°). The 60° & 120° & Base Alignment show the Min/Max points, and I get the Major Ø. The Min/Max points in the Y axis in alignments 30°/90°/150° show the points in the wrong locations.

[[Ch...]]

Here is what I do with supercharger rotors. Basically I scan the entire profile with a 3d curve, it could be a 2d curve I suppose. Then I recall feature points that curve into two circles. One with max inscribed and one with min circumscribed. Those two circles then output outer diameter and what we call root diameter.

male_coated_profile Curve Evaluation.PNG

[[Cl...]]

Great idea, thanks!