I believe that this is only a display issue, but it still worries me, Differencing my bas cyl like shape that lists as a closed polysurface seems to delete the lower cap, yet it still lists as a closed polysurface.
BSP-2B-PC IM 630-lid-lugs.3dm (2.9 MB)
“What” shows: “Geometry:
Valid polysurface.
closed solid polysurface with 49 surfaces…”
How did you create these polysurfaces?
Part of the problem could be a short segment on the boundary of your base surface.
outline->planarsrf=>delete outline curve->exrude surf->verify closedpolysurface.
Update, saved as stl shows it is closed
_ExtrudeSrfTapered ???
A straight extrusion works fine…
Injection molding requires a taper in order to remove from mold.
Yes but you cannot expect a short segment to extrude correctly…
Why not, it’s just math? It worked just fine on previous models.
What taper angle are you using?
3 degrees every time.
Ok. I see a short segment with a length of 0.008 inches.
To demonstrate the effect, I extruded a square surface with a side lenght of 0.008" with 3° taper.
0.004 / tan(3°) = 0.076… and then there’s tolerance
I was able to extrude square with the side length of 0.008 inches with 3° taper to a height of 0.0597, anything higher failed.
You will have to clean up the surface you extruded or add fillets after the extrusion.
Pure math.
Hi @KMAC,
The taper has resulted in one or more self-intersecting surfaces which will screw up your boolean:
HTH
Jeremy
EDIT: The odd semi-transparent display is a clue to the presence of a self-intersection.
thanks guys
I’m having the same issue. Making me crazy. Wasn’t happening last week. Any ideas?