Lofts fail after any rebuild,

I have a model with some semi-complex surfacing, nothing crazy. The
thing is, if I change a dim in one of the sketches to force a rebuild,
some of the lofts and what not get confused and I have to set up half
the model over again. Edges that were guide curves jump to profiles
and vice versa. Some edges just diseapear from the features.

Am I missing something, or does this completely defeat the purpose of
parametric modeling? If I have to go in and fix everything for the
tiniest change, then I might as well just be working with free form
nurbs surfaces in an art program. Is there any way around this?
Somehow force it to remember which curves I told the features to use?
I am using SW2007.

Kyle

 

Yes- I have this issue too. I am not sure how to stop edges from
jumping around so much. I suppose we need to rely on sketch geometry
for more stable geometry. i am trying to model more in Solids these
days if I can help it, as much as I hate it. Even worse is when a
features fail in alternative rebuilds. Sometimes I have to hit Ctrl-Q
twice and on each alternative rebuild the lofts sometimes snap back to
design intent. No rhyme or reason sometimes.

 

What really sucks is that I intended do use a design table to set up a
bunch of variations for FEA. Definitely not going to be fun fixing
all the features for each rebuild!

 

Consistently inconsistent is SW Corp's moto!

Over the years, per release and sp, this has been a on going problem
which SW Corp NOT solved.
So, remember to thank the developer/programmers which consistently
fail to solve this problem..

This inconsistent flipping problem shows me there is a MAJOR FLAW in
their programming and they NO INTEREST IN FIXING IT!

But, in trying too help,... look back at your sketches and see were
this could be failing...
Sometimes it's old splines which behaves badly...
Sometimes it's a tangency condition which flips...
Sometimes it's how you reorder your sketch that effects a condition of
direction...
Sometimes it's a shared sketch which effects a condition of
direction...
Sometimes I want a hammer to break this crappy code!!!

In my experience, it's something in the original file... a sketch or
feature legacy problem? So, no matter what you do, it will NOT go
away!

i.e.,.. a girlfriend (boyfriend) with baggage... no matter what you
try to do, the problem always seems to come back.. So, you dump the
bitch (bastard)!

With that said... what I'd suggest is you start over, redo the part
from scratch,.. do NOT use your old templates, use someone elses or
the latest version default template.
Or, do a sketch early in the feature tree which is not effected by
other parents.... and copy that sketch.... this does not always work
but it might..?
or, redo the sketch and feature and try to reassign the children,...
again, it does not always work but sometimes it does.


Good luck...