SolidWorks and repeated patterns
Gavin McKeown
on handling large arrays of repeated features in SW99...?
I work in the biotech industry where our most common vessel is a
microtitre plate with either 96 (12x8), 384 (24x16) or 1536 (48x32)
wells. To model these plates in SW is _painfully_ slow on what was a
top-of-the-line computer last year (550Mhz Pentium III, 512Mb RAM, SCSI
Ultra 2 disks). I know I can suppress the repeat patterns, but that is
only avoiding the issue....
Is this just something I have to live with or is there something I can
do...?
Any help would be appreciated.
Thanks
Gavin McKeown
matt
every case, the "Geometry Pattern" switch can be used in the pattern
dialog. This essentially patterns dumb geometry rather than patterning any
parametricity/intelligence. It does speed it up some. It may also depend
some on the size of the features. If the holes are small (<.001"), you are
likely to take a bigger performance hit due to display issues, especially
in any wireframe/HLR modes. A cheap alternative would be to make a sketch
pattern to show on the drawing.
Which brings up something else. What are you using the actual geometry
for? If you are not doing something that requires the holes, there may be
no reason to include them in the CAD model. If the holes are small, they
would cause more problems than you need in a STL part, the process would
bog down and the usefullness would be questionable. If you're going to
CNC, the first hole would suffice, and use the CNC to program the pattern.
Any sort of analysis requiring mesh would also choke at the large number of
elements. My idea is to pick your battles wisely, and never fight against
yourself. Not knowing the product or the application (although it sounds
like a filtering app), I could be way off base.
Matt.
Gavin McKeown wrote:
--
Matt Lombard
CADimensions
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Gavin McKeown
I'll try the Geometry Pattern trick...thanks.
I've been doing them as feature patterns rather than sketch patterns
because I need to be able to go back and edit things like # of repeats
and spacing once the model has been built. Correct me if I'm wrong, but
sketch patterns don't seem to have any associated rules about how they
were generated - i.e. if you pattern a fully defined sketch, the added
sketch elements are not fully defined.
As a bit more background, the features are needed more for visualisation
with scientists than for machining data, although some of the time we
are machining our own 96,384 or 1536 patterns. The application is not
filtering however, these are individual 'wells' in a multi well plate
(either 96,384 or 1536 wells per plate). They are used to store and work
on biological reagents and samples. They are anywhere from 8mm dia to
1.5mm dia.
Gavin
John Picinich
I've been working with some rather large feature and sketch patterns
recently (38x38 linear patterns = 1,444). The rebuild performance time is
about 2 minutes on my PIII-600, NT SP6, VX1, 640 MB RAM.
FYI - SolidWorks 2000 will support parametric linear pattern definitions for
sketch patterns and feature patterns. Two additional feature patterning
types will also be available, Table Driven (Excel) and Sketch Driven. These
will provide easier ways of controlling irregular patterns.
Hope this information helps.
John Picinich
www.cadimensions.com
"Gavin McKeown" <mck...@mpi.com> wrote in message
news:38C444D9...@mpi.com...
Gavin McKeown
In that case, bring on SW2000...! Mind you, even with these other
options, will it rebuild any quicker..?
I've been trying the 'Geometry Pattern' option and I can't get it to
work. I just get loads of error messages saying the 'seed features can
not be used to create solid bodies' (or something like that).
It's not even that it's an irregular pattern, just that I need to be
able to make little tweaks to it as the end user sees it and evolves
their requirements.
Gavin
Edward T Eaton
When using a geometry pattern, the seed features error message comes because
your patterned feature hassome face that must merge with other faces in the
model. For instance, you can not pattern an extruded square if one of the
edges of the sketch for the square is coincident with an edge on the base it
is being extruded on, causing the face created by that extruded edge to
merge with the face of the base. If all of the edges of the square are
inset a hair (or overlap) the base it is being extruded on, the feature will
pattern with a geometry pattern. I think this restriction comes from how
SolidWorks has to name faces and edges that get created in models... since a
feature pattern with a 'seed feature...etc' problem doesn't create new faces
with each instance, but shares a face with existing geometry, SolidWorks
can't take the geometry pattern shortcut.
I'm sorry if the above description is hard to understand. This problem is
much easier to understand if you are looking at a part in front of you, but
is a real bear to describe (or diagnose... they really have to learn how to
give descriptive names to errors over at SolidWorks!!!).
-Ed
"Gavin McKeown" <mck...@mpi.com> wrote in message
news:38C55D4E...@mpi.com...
Edward T Eaton
If your pattern is just for visualization, you might consider using a
bump-map or decal in Photoworks to show this pattern in a rendering. We
have to make pegboard all the time, which is real slow to model but very
fast when done with a decal and looks the same in presentations.
kellne...@my-deja.com
want to get the notes.
As has been mentioned, face ownership makes all the difference. The
feature to be patterned must stand on its own in terms of owning its
faces. Also if the feature is constrained to reference geometry those
constraint will remain and strange results can ensue.
Sent via Deja.com http://www.deja.com/
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