Importing STL file difficulties

I have been reading lots of past posts but am still confused about
solidworks cababilities. I have imported an STL file into Solidworks
2004. I was not sure whether I wanted to import it as a 'Solid Body '
or a 'Surface Body'. So I tried both. The 'Solid Body' option
imported to a blank screen. So I tried the 'Surface Body' option. An
ominous warning appeared "a facet normal problem was found on one of
the facets. Check your STL file." but it seems to import ok. Now for
the real question. I want to be able to cut holes into this model. Is
this possible? I can extrude bosses from the surface but the cut
options are not available to me. Am I doing something wrong or is this
just not possible? Thank you for any help.

 

I haven't played with importing STL files, but the fact that you didn't get
a solid body is probably an indication that the surfaces weren't closed, so
SW couldn't build a solid. When importing other file types, like Parasolid,
IGES and STEP, it usually brings in the surface, but perhaps it doesn't for
STL.

That bad facet (surface) normal could be the reason that it couldn't build a
solid. As I recall, the surface normals determine what's inside and what's
outside the body. When all the surface normals don't face the inside or
outside, it can't make up its mind what's in and what's out.

You might be able to use the import diagnostic tools to fix the bad surface
normal. Alternatively, you could remove the bad face and replace it with a
planar or fill surface. If that is the only problem, so that the surface is
now closed, you can thicken it to make a solid.

Surfaces, being the ugly stepchildren in the SW world, their user interface
is different. You have to "trim" a surface, not "cut" it.

If you really want a hole, with sides and a bottom, you will either have to
make those surfaces or turn the STL part into a solid and then cut the hole.

Jerry Steiger
Tripod Data Systems
"take the garbage out, dear"

 

Although you "can" import and solidify an error free STL, their true
usefullness in Solidworks is pretty much limited to visualisation.
STL's are polygonal approximations. They don't contain any real geometric
information at all. You certainly wouldn't want to use them as part of a
real documented assembly.

What would be really nice is if SW provided tools for smoothing and
rendering polymesh files (al-la Iron Cad) for use as props in renderings.
There are sooooo,,, many of these available for free. It would save some
people allot of time. As it is, rendered STL's look like something you'd see
in the Flintstones.


Regards

Mark