Please tell me why...

[sadrok]

I am trying to give the benefit of the doubt and not assume my way is best. I am working on a model that consists of 475 features. 100 or so of which are cuts made to remove material that could have been easily been removed by editing a dimension. For example, A 2" long pin needed to be shortened to 1-3/4". Instead of changing the dim. to 1-3/4" they created another cut to remove 1/4"! I am told by the person who did it that in an effort to save time and not have to revamp the whole model, the cuts were used instead. Other features reference the top of the pin at 2", so if it's changed to 1-3/4" by dimension, the other features either fail or move 1/4". The model takes over 20 minutes to open, but no one wants to fix it because it's too involved now. Has anyone run into a situaton like this or something similar?

 

[Moroso]

I used to run in to it all the time, after years of btcnand trying to fix the models I just gave in and hacked away.


The only reasons I could come up with why people don't fix the models are:


1. The models were created over a long period of timeby several differentusers,which in turn have different skill sets and don't know how to either fix it or properly interrogate the model.


2. Laziness

 

[AHA-D]

3. Plain fear of resolve-mode-hell. If you're already in a shaky model then the tiniest change can bring the whole model down. If this is 475 features I would also be scared. Then again a model with that many features is most likely not very well conceived. I would rebuild it.


Alex

 

[Dell_Boy]

Another major barrier to fixing models is caused by inability to re-order features to a more suitable place in the menu tree. This is often caused by inexperienced users using totally irrelevant surfaces and edges to orient and reference sketches which generates frustrating parent-child relationships that block attempts to re-order.

I would bite the bullet and re-build it too; particularly if you have to use it more than once a month. I have received many badly built models over the years but yours sounds particularly nasty and a 20 minute open time for a single part is a bit of a joke. CAD is supposed to improve productivity.

One thing to especially watch out for is a general small fillet radius or big pattern early in the model tree. This can really slow the model down. Also, when the model is opening, watch the feature count as it is regenerating. See if you can identify where it slows down and if possible move that later in the tree. Another trick with big patterns is trying to sketch a cluster so you can reduce the number of pattern increments. Particularly useful with grille type patterns.

Before you rebuild it, consider exporting it as a step file so you have a relatively quickly loading reference model to compare you work to.

BTW resolve mode is a dream compared to what it used to be. Hands up those who remember seeing the menus Trim/Suppress, Clip/Suppress etc


DB


Edited by: Dell_Boy

 

[conrat]

We are running in to this on our complete product assembly for one our
largest products. We drive this model with over 100 input
statements. Because of the nature of the product, it must be
configurable to this extent.



Anyway, the guy who did the model basically just started assembling
parts. The entire model hinges on the very first part in the
assembly. It is like a house of cards, where nearly any changes
(redefine, removing cuts, etc.) made to the model causes a failure.



Every cut in the model is an assembly cut that was referenced from part
geometry of assembled parts. Because many of these parts are
often supressed through the input statements, other part placement
references constantly fail.



It is a perfect example of poor planning.



Needless to say, we are rebuilding this model, using top down and
skeletons. The use of skeletons provide nearly bullet proof
referencing entities which do not fail just because a part is supressed
or cut removed. It also allows you to place all of your geometric
refs in one place foreasy management.



Pro/E is a great tool, but it is not AutoCAD. Unfortunately, many
people using Pro/E are drafters who have worked in 2 their whole
life. I think many do not understand parent/child relationships
which is why they freak out as soon as the Failure mode kicks in.



One thing I do hate about skeletons is, when you publish geometry, you
cannot do reference patterns. And if you publish the entire
patterns, you still cannot reference pattern. The only way I have
been able to do it is with an inheritance feature. But that sort
of sucks if you are far along with a model, as rerouting all of the
features can be cumbersome.



I will get off of the soapbox now.

Jim

 

[Baptie]

Worst exampleI have seen was someone putting an assembly cut throughnearly 400 components so they would be left with a small fascia insert model that lined up to a printer - excuse was that theyhad created thefascia features in assembly mode and were too busy to redefine it when they finished.


Plenty of examples of holes filled in with protrusions, dimensions from a point in space that has been cut out the model and material cut of models then added back in later.


Tried to implement model check and set it to reject models with buried features - project managers forced CAD support to turn it off because it took so long to fix the models.

 

[design-engine]

That would take a long time to regen. Worst example I saw was
way back in 1994 at a major manufactuer. As a contractor I had to
take over the housing. 1400 features and almost half did
nothing. Well, say one feature added an extrude and another cut
it off. 700 of those gets old. I deleted almost 700
features and waided thru all those fails. Now I am the best at
fail mode.



Good comes from having a good attitude.

 

[conrat]

I must say, working through crappy models has helped me learn resolve
mode. I am very confident when entering into a failure now, as I
have worked through so many in the past. Maybe others poor
modeling practices have actually been a blessing. Though a huge
PITA.

 

[sadrok]

I'm glad to see it's not just me. I recently ran into another model created by
the same knucklehead and the drawing took 2.5 hours... That's right, I said
2.5 HOURS to open. The same person who created the original mess, created
another horribly inefficient model and then created multiple instances which
only adds to the regen time.

 

[conrat]

sadrok



I am sure "knucklehead" was not your first choice of labels. I
can think of about a dozen more colorful titles, but will refrain from
posting as to not upset the moderators.



Jim

 

[sadrok]

The "head" part is right, just insert a different word for knuckle.

 

[conrat]

Something like that...

 

[Dell_Boy]

I trust that the f**k-knuckle is now an ex-employee

Edited by: Dell_Boy

 

[Jacoolo]

just two cents more about repairing bad models


In such situation I used to use backup model option in Resolve mode, to see what was the lost references or other missing stuff


but since the Pdmlink with Workspaces was implemented I lost the advantage of making save as independent file


so then there is no chance to use backup model in Resolve mode while working on Workspaces

 

[sadrok]

I'm sorry to say that the "bad modeler" has everyone else convinced that he's
a wiz with Pro because he gets things done in no time. They don't
understand the mess he's creating because the "higher-up's" don't use Pro.
And if all else fails, and you do challenge his skills, he plays the race card.

 

[conrat]

When I told my bosses how long it would take for me to fix these
models, they couldn't believe it. But once they sat with me and
had me show them the problems, they quickly understood. Planning
is a big part of modeling, especially if you have a really dynamic
model that changes constantly. This time around, we are
doiong much more planning and are realizing a much more stable model.



Jim