extrude from planar curve

[smoker]

Hi, I am trying to extrude the attached plate.
All the holes (besides one) in the plate are OK.
But the big middle hole is never taken into account.
Does anybody know why?

David

[chmillman]

The big curve won't extrude because there are 3 little extra segments in there about 1mm coinciding with the joint of two bigger segments.

Ungroup your curves, find the little segments, delete those and then try extruding again. --ch

[smoker]

Hi, brilliant, it works now.

Just for my info, do you know why this did not work with those small segments?

David

[chmillman]

Yes - when you extrude solid, Rhino tries to find closed loops (all loops have to be closed for a solid). With the extra segments Rhino got confused about how to close the loop and I guess the programming is set to ignore ambiguous input, so it just pretended the whole loop wasn't there. You would have known as well if you had tried to join all the curves and checked to see if there were any open ones. But sometimes it's difficult to catch this stuff. When things don't extrude right, always go back and check the curves. --ch