Need some advanced surfacing tricks

I'm trying to remove some fillets from a complicated imported part that
we're making a mold for. We don't have FeatureWorks (not that it'd work on
a part like this) and we really can't ask the customer to do it at this
point. Here's an example of what I'm talking about:

http://www2.primushost.com/~jlmoore/images/Fillets.jpg

The fillets highlighted green are the type of thing I'm trying to remove.

I'm looking for suggestions from people who may have gone through this
already. I know how to use the surfacing tools in SW but to me this seems
like something it can't handle too well.

Thanks for any advice,

Joel Moore

 

Can you try importing the file to Rhino3D and doing the work there? It
really does surfacing much better than Solidworks.

'Sporky'

 

I had an eval of Rhino installed for a while but once we got SW 2004 I
stopped using it. I pretty much only used Rhino for untrimming surfaces
and now SW does that.

In general, Rhino frustrated the hell out of me so I never got too deep
into it. Maybe I'll put some more effort into it once I have the time.

 

seems to me that you would not need to use surfaces but then again I hardly
ever use surfaces but you might just draw a box where the vertical edges are
pierced to the tangent points of the fillet -- then use one tangent edge as
a sweep path & the other tangent edge as a guide curve. You will probably
have to create separate sketches for your path & guide curve by creating two
3d sketches & converting edges.

good luck

Steve Tietz

 

oop I just had another look at the image -- a box probably will not work
since the vertical edge would not match the curvature of that front face...
sorry

so you might try using offset surfaces with values of 0
then untrim all surfaces
& extend up to surfaces to get the edge to meet
then Knit all surfaces together

then try making those surfaces closed by offsetting & trimming with the
fillet & solidifying those surface & Join the solids
or just create the corner as surfaces & extrude a solid shape upto that
surface.

maybe that will help?

Hard to know without having the actual model
Steve Tietz

 

Joel,

So, deleting the blends and extending the faces and trimming does not
work?
Anyhow, try and delete the green highlighted blends and extend the
boundaries and trim.
Or, if it is faster, instead of deleting the blends, copy offset "0" the
faces you need and and extend them and trim/blend.
There are other ways you can also approach it if the surfaces are not
behaving but it means rebuilding those faces, such as, fill surface or
lofting.

Good luck.

...

 

First make sure you do a Tools, Check on the geometry, with validation
turned on. Next, I would run an import diagnosis, and ask it to
improve
the geometry. You can also use import diagnosis to remove faces, but I
would do that with the feature based tools, because diagnosis leaves no
history of what you did or way to undo it other than reimport.

Are you having problems deleting the faces or closing the gaps? Have
you tried to delete all the faces of the fillet and let SW close the
gaps on the solid (without leaving it a surface model) automatically?

http://users.adelphia.net/~mjlombard/filletsmatt.jpg

If you have to do this manually, the section where the smaller fillet
runs into the flat face (blue arrow) will need to be trimmed square
before it will knit solid. That combined with the fact that the edge
that feathers into the smaller fillet (red arrow) is likely to create
some very nasty small edges will give you some challenges. You may
need
to construct a new surface in this area instead of trying to extend the
green arrow face. The new surface will need to be an extension of the
face indicated by the black arrow, or it may be easier to delete the
black arrow face and just recreate it altogether, and trim it with the
flat face with the hole on it.

The larger fillet looks fairly easy from this distance.

If you get really desparate, email the part. It may take some
swearing,
but I think this can be done.

matt

 

If the model is solid or there are no gaps on the fillet edges, remove
the fillet faces using "Delete Faces". This will allow the adjacent
surfaces to grow back together. Then apply a matching fillet in SW
(be sure to save a backup copy to measure).

You will need to experiment to see how many faces you can delete at
once. Usually deleting an entire continuous face set works well.

 

if you knit the faces and have a good import you can also insert a thicken
feature to make it a solid and then do the same thing The Tick suggested

Corey

 

Thanks everyone for the replies. Most of what you're saying agrees with
how I figured I'd have to approach it.

Part of the problem is that the original import wasn't able to form a solid
due to several translation problems (the customer is using IDEAS).

So I essentially just peeled apart the model using the surface offset (0
offset) feature and exported the various sections into new models that
represented the various pieces of the mold. So the result is that none of
these fillets are solid.

I guess the thing that started driving me nuts is realizing that a surface
can't be extended up to or trimmed to itself. So replacing those missing
fillets requires a lot of face duplication at the least.

But at least I see now that this is pretty much the way to do it.

Thanks for the advice.

Joel Moore

 

I guess the thing that started driving me nuts is realizing that a surface

Not even with surface>untrim? I have had great luck with that, but I think
it has to be a BREP model (untrim modifies the boundary exposing the full,
untrimmed surface)

 

Joel, something you said here made me realize there's a trick that may
help you. In importing your file from IDEAS select Options (from the
bottom right of the "Open" dialog box) and select the radio button that
says "Do not knit". Doing so will import your surfaces separately so
that they CAN be knit later. If you don't select this option you get a
single COMPOSITE already-knit surface that cannot be knit to itself
(when you try to use the Knit command).

Mark 'Sporky' Stapleton
Charlotte, NC