Shell Warning question

Just got a warning when using the Shell command - never had this
wording before in 7 years.
However it is the first time I have used a curvature continous fillet
is a part.
Sw2005 sp3
" To allow shell to complete, an internal tolerance has been relaxed.
Downstream operastions that use this shell's geometry may have
problems."
Is this something to worry about ? What tolerance has been relaxed?
The model then rebuilds fine and no further errors even though there
are about 30 features after the shell.
Anyone seen this before.
Regards
Jonathan Stedman
Reply to
jjs
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Yes seen it often with swoopy stuff. It usually means the shell has a pinch point somewhere where the new surface struggles to offset sweetly. Rather than have the shell fail there the geometric conditions have been relaxed to allow the shell operation to work anyway. Sometimes if you run a section view through it or use the curvature display you can actually see a warped, knotted or distorted region. At a guess in your case a nice offset of the curvature continuous fillet probably cannot be maintained exactly inside because it is slightly too sharp there after taking the thickness into account -so what's been created by SW doing it's best, may be thinned or thickened there or not particularly tangent or smooth. If your mission is critical you can often perform some surfacing surgery or it for better results. Do a Ctrl Q on it before you say it rebuilds fine though because the errors may be not apparent at the moment. HTH neil
Reply to
neil
Ditto to what Neil said and I'll add this:
1. I have seen this with legacy models. SW has changed the shell algorithm over the years. It is possibly more stringent now than it was.
2. In addition to CTRL-Q rebuilds keep Verification with Rebuild turned on as this is a very stringent test of the geometry.
3. Run the check command often. Found in TOOLS/CHECK
4. Check into what Ed Eaton has written about shelling in his Curvy Stuff series. Search google to find it.
Reply to
TOP
Neil & Paul
Thanks for this - I'll defiantely turn the verification on for this model.
Jonathan
Reply to
jjs

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