Surfaces created using polygons, unable to shell after creating solid

bowl on2cook sandy.stp (1001.0 KB)

This is created using a polygon, and then surfaces using the scaled down polygon in the center, then raised height of the central portion. had difficulty in capping the bottom surface, had to trim and then cap, and now if i sheel, .6mm - it creates an open surface.
Eventually had to take it to solidworks to make it work. Frustrated.

Any ideas what is wrong??

Shell command works fine on the closed polysurface in the attached stp file.

When you do this on the step file, it works. When i am doing this on the rhino file (and not the reimpoted step file), this is what i get to see. Well i was trying to do .6mm shell towards inside…

Please find attached the Rhino file, where you cannot shell.
Please help me understand what is wrong with the geometry.
thanks in advance.
20221001-TOP BOWL PAN-V2 sandy cad for upload.3dm (74.1 KB)

This is your problem:

If you set a tolerance to something more reasonable for Rhino like 0.001, the shell works fine on this object. It even works at 0.0001.


Understood. Thanks a lot. The latest Rhino 7 trial version has this absolute tolerance .00001 as a standard value. So i did not bother to look at it.
I thought this is the new standard and they might have done so that export to most other software gives no problem. Earlier i would use 0.01 and sometimes it would show open edges in Solidworks.

Really? If that’s the case, then it’s a bug. Rhino doesn’t work well at that low a tolerance. The recommendation is not smaller than 0.0001, for mm/small I recommend 0.001 which should be standard in that template. Are you absolutely sure you haven’t accidentally modified yours?

the default should be .001…

did you import your model? if so it may have brought that higher tolerance with it.