weldments and in-context troubles

Hi all,

I've gotten myself into a bit of a corner with a project (due soon of
course!). It's a lot of SS and glass and a perfect application as a
weldment - so I modelled the whole thing as a weldment not realizing
at the beginning that the body count would get too high causing SW to
slow to crawl. I ended up with 929 bodies in the weldment - the part
was unusable it was so slow.

So, I started over (had revisions in any case) as an assembly,
inserting a lot of empty parts into the assm fixed to the assemblies
default plans, then geometry created in-context. This project sort
of demands either in-context modelling or a massive skeleton sketch to
establish all of the intersections.

Everything was going well in the assembly, nearly finished when I
encountered 2 major difficulties: First, sketch geometry that is set
to construction and 'at the intersection of 2 faces' continually is un-
checking the construction switch, causing lot's of errors - editing
the sketch and rechecking construction fixes it but only until the
next rebuild.

Second, at some point I ended up with a bunch of parts with rebuild
icons that will not clear - I'm pretty certain I don't have recursive
in-context relationships but these rebuilds wont clear at all.

Is there some diagnosis for understanding these non-clearing
rebuilds?

TIA

Zander

 

My guess as to why the construction geometry is being switched off is
this: Since the intersections are incontext they are being
recalculated each time you rebuild the assembly and therefore by
default are not construction. If this is so, then by the same token
you are always going to have rebuild icons.

Try locking external refs after you are done with a section of your
assembly. That may well confirm my hypothesis.

TOP

 

I'm with TOP - It sounds to me like the 'at intersection' is being
remade every rebuild. If you are finding the intersection of simple
planar faces, you might try removing the 'at intersection' and instead
just piercing the endpoints of the construction line to edges/sketches/
etc of the referenced component (or in a 3D sketch, make the line or
endpoitns of the line 'on surface' to both planar faces). If the
surfaces are not planar, you might have more robust results from
making a surface out of one faces and using the other face as a trim
tool to get the 3D curve you need - it is an unfortunate step, but it
is a LOT more stable than intersection curves, as you have found out.

How many of your components are in subassemblies? I am seeing much
less of the persistent rebuild icon since I have become a zealot about
subassemblies. I want as little to solve in the top level asm as
possible - mates, in-context, you name it.
Granted, I might have also changed something else in my methodology
that makes the persistent rebuild icons go away and the subassemblies
are just a red-herring, but my gut thinks it helped.

Anyway, good luck and hope this is helpful in some way.
Ed

BTW - good to meet you at SWx world. I tried sending an email to you
last Monday or Tuesday about that session I couldn't go to, but the
email got rejected by your server.

 

Hi,

I've solved most of my rebuild issues by transfering most incontext
information to a skeleton part. Interestingly the only persistant
rebuild icons I'm gettings are on mirrored parts that are mirrored in
the part file (pick a face, select 'mirror part' saveas new name
etc.). The mirrors that are in the assembly always want a rebuild
whereas the parents are fine. I note that if I mirror the part at the
assembly level, letting it save a new file then these do not have
persistant rebuilds.

It's a project that originally was a weldment but when I finished it
as a weldment (all stainless steel pieces) the performance got so bad
that the part has it's own spr now (SPR 363824) . Ultimately I could
have split it into several smaller weldments but then half of the
parts changed to sheet metal as a last minute design change.

Not sure what's up with the email? It was great to meet you as well.
Try emailing to my comp.cad address (gmail) and I'll follow up from
there.

Zander