Tangency issues

Hi All,
I am having trouble with the tangency on this part i am working
on. i am not sure if i have approched the problem in the best way. The
swirl repeats itself 3 times around the cylinder, so i cut the cylinder
down to a 1/6th segment. Created the splines on a 3D surface and then
mirrored the body to give me a 3rd, it is here that you can see a
crease in the swirl where the mirror line is and i am not sure how to
make it smooth. Then circular pattern the body 3 times to make it whole
again (although it is 3 seperate bodies?). Have i gone about this
totally wrong is there an easier way? Any help or tips would be very
much appreciated.

www.michael.lynn.net/tangency-help-ml01.zip

Thanking you all

Michael

 

Several things ...

The arrows at the ends of your guide curve splines nearest the symmetry
plane are not perpendicular to the symm plane. If you check them out,
they have a small angle, such as .01 deg or some such. Deviation
analysis shows a max non-tangency at the mirrored edge of a bit over 3
deg. Fixing the spline angle brings the dev analysis down to just over
1 deg.

Also, you might try using a pierce relation to locate the profile from
the gc.

You're better off lofting all the way across the plane of symmetry if
you really want it to be smooth. Slightly more involved set up, but the
results would be worth it.

It's not at all clear to me why your profile sketch has two non-
concentric circles. If I were doing this, I think I would use a full
circle, give it a relation to the GC, but make a sweep instead of a
loft, using the GC as a path and setting the twist to 0 turns, and
create the whole thing rather than counting on a pattern/mirror doing
the trick for you.