HalfCosine Spacing will see sweep profiles without same point count


I am using the principle of half Cosine spacing to redraw profiles. An aerofoil profile to have 16 or 32 segments. This is as per article by skyg :-

However in my elevator I am sweeping parts of these profiles and each one is less and less of the entire full profile length.
Rail B being the chop line for them.
So consequently my half cosine redrawn sweep profiles will have less and less of the matching number and location of points required to meet correct sweeping rules.

I have redrawn one profile as can be seen so far using the article method and suggested 16 or 32segments and I have found that 16 advised for elevators doesnt allow InterpCrv to capture the leading edge, so I will try for 32.

I also placed my last click at end of the straight line and will split and re-use the eliptical edge as the method disallows capture of such shapes. I wonder if the semi circle template should end at that point and not at the extreme tip before starting to redraw the profile.

Why not sweep full profile then chop up the surface aft of the line, well one profile isnt full length, it doglegs and I dont have a shape for its straight profile. and another I only have as far as the line I am interested in anyway. Also I am trying to follow principle of keeping trims to a minimum, for when MatchSrf etc gets used.

So should I draw each partial profile with 32 segments ? That will see the distribution of the points along the profiles get more compact as they get smaller, is that ok ?

file attached (and yes one profile is not quite perfect CurvatureGraph wise as its impossible to fix without altering frame which then alters trailing edge structure and so on.)
WhatIfPartialProfilesInUse_PointCountPrinciple.3dm (60.0 KB)


Needing to progress I have opted for what I think is correct, and that is to ensure that each sweep (or loft) profile has same point count and deg and structure.

using skyg halfcosine method I create arc and divide 32, trace the profile with InterpCrv and get 35 control points.
deleting last control point before profile tip to maintain 32 segments as per article.

However, despite 32 segments the trace of station 2 sees a mismatch of curve.

trim and joining in the radiused tip and shape sees cp count and position mismatch.

Going back to the trace and nudging Cp’s up and down improves it a bit.

Any advice please on how to deal with this one ? Keeping point count and distribution yet obtaining a better trace ?

Oh if only one could just draw curves and sweep them without having to play to a rule of same cp count. As beginners to Rhino might assume.

32seg template InterpCrv trace stn2 dilemma.3dm (82.0 KB)