Dear Michael,

Thank you very much for your reply. The separate sweeps are giving me almost exactly what I need but I cannot create the planar surfaces. If you have a moment to look at the attached I would be most grateful.

Thank you.

Philip

Hi Phililp, the sides you have there did not end up being planar, if you switch to the Right side view you can see:



Notice how the profile is kind of curved and shrinks inwards near the bottom?

It looks like your middle profile curve is not quite as wide as the others, so it does not end up tracing out a planar shape along the sides.


So instead of Construct > Planar for those particular areas you will need to use some other technique, like for example select these 2 edges and then run Construct > Loft :



Or you could also use sweep with those 2 edges as the rails and the little line as the profile curve, or you can use the other technique I showed above where you would cut in those side pieces with booleans instead.

- Michael

Michael,

Many thanks for all that information - problem solved and a few other subtleties that I hadn't appreciated highlighted too.

Regards,

Philip

Hi Philip,

Another option I sometime use when having to do a half shank like your example is to make the 3 profiles identical at the start.
Then with the middle Profile you can Scale 1D to adjust its height or switch on Points & move them to suit your needs.
Because all the Profiles have been made the same way, they'll then Sweep correctly.

HTH, Colin

Hi Philip,

I often use Colin's method when building the lower part of the shank on a signet ring.
Having the same number of control points in the profile curves helps to steer the sweep in the right direction.

I took another approach to build a shank that still has the flats on the sides at the base, but without the sharp creases.

I filleted 2 corners on the bottom profile curve just a little and then drew an arc
on the outer side of the shank. Then all the curves were used for a network surface.
I did a 0.2 mm fillet, but you may want to use a smaller fillet..it will still work.

When modeling a signet ring in two halves such as this, the lower shank must blend well into the top of the ring, so that must be considered
when drawing the outer arc. You can sometimes use the "cont" arc to make a good transition between the top of the ring and the shank
Hope this makes sense.

Jesse

In Michaels method, where he cuts the sides of the ring off, if you be carefull to keep the seam edge out of the cut, I like to use the "Blend" tool to create the "fillet". Just delete the flat face. Can almost make a variable fillet.