imported geometry

I imported a design created in Rhino. I use this design only for the
look. I am curious to know how others work from imported geometry. What
I do is try to re-create all features in SW. Sometimes due to complex
surfaces, I use the imported surface and create an offset of that
surface. Now my part is related to that file due to that surface. If I
break external references then I get errors in my SW file. I f I leave
it, I run the risk of someone losing the orig file that is made in
context. Can anyone suggest other alternatives to getting the surfaces
from the orig file without problems? Thanks

 

From your post, I gather the imported geometry is in one file, and the
coied/offset geometry is in another file, and they are linked in
context of an assembly.

Why not just work directly off the imported model?

I am finishing a project where exterior surfaces were determined by an
outside industrial designer using Ashlar-Vellum. I found that most of
the Vellum-generated surfaces could be reproduced as sweeps, usually an
arc or ellipse swept along a spline. I would offset and untrim a face
from the imported geometry and then use that surface to determine
curves for sweeps.

 

I tried working from the imported geometry but usually there is no
draft on the parts and I have to add that. Also, I like to re-create
the geometry so that I have the flexability to modify easily if
required.

I don't know what is worse, working from the original geometry or
offsetting some surfaces and then having to rely on another part/assy
for the in-context stuff.

 

Try ShapeWorks at www.baren-boym.com

ShapeWorks can extract all the surfaces to new or existing file. The new
surface model will not depent on the original.

Michael

 

I've had the time and ability to recreate everything from scratch. For
me, the imported file serves as a template to match up lines and
compare surfaces.

Remember that most faces you see on an imported model are trimmed
patches of surfaces with larger definitions. When these surfaces are
untrimmed, it's often not too difficult to divine the surface
construction and replicate the surface in SolidWorks.

It is important that this be done with untrimmmed surfaces (which are
then trimmed/knit as needed). Attempting to replicate a surface based
on trimmed edge geometry usually results in surfaces that are
overdefined, which results in odd wrinkles.

 

Here's been my experience. I've taken an original imported part and
used is once and added all my features. I didn't like that because I
want to be able to change all entities if required. I've successfully
re-created parts using (as you stated) the orig import as a template.
I've also created parts the same way but had to use offset of an
imported surface because I could not duplicate. The reason I am asking
how everyone does it now is because on this new project I have having
even more of a difficult time duplicating surfaces and I am finding
myself using the offset (in context) a lot more on this project. I am
just trying to avoid problems in the future with these parts. I guess I
need to work on creating original surfaces in SW and matching it up
with the import?

 

It's a tough call. All design is about context. You can make your best
educated guess, but sometimes design intent shfts in such a way as to
blow your foundation apart.

In my field, it is common to be dependent on imported geometry to
define a design. The risk is that the very foundation of the model may
change.

There are tools to cope with this. Imported feature can be redeifined
without creating a new file. Models can be structured to minimize the
damage done by replacing "foundation features". It is important to
learn how to repair features by adjusting/replacing their references.

 

I hear what you are saying. I've run into problems in the past where
the import changed and my design was in context with it. SW tech
services say not to build in context. Makes sense but does not at the
same time. I usually build in context and then break the associativity
and put my own dims in. My particular problem right now is I can't
define some surfaces without using imported surfaces. If I try to break
the context of the surface I get errors. Not sure how to handle that.

 

That's our theory. If we can't match the original ID in SW, then we change
the design enough to make it work in SW. Next project we are hoping to set
up tighter design rules (primarily minimum radii) with the ID firm before we
get started with the surfaces. Since our favorite ID firm also has SW, we
will probably ask them to give us shellable SW models.

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