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Hi Jonathan...
There's an art to creating models in Creo (and Pro/E). Part of that art is understanding how to make a robust model. There are times I would definitely disagree that sketches should be kept to 4-6 lines... or that chamfers and rounds shouldn't be added to a sketch. Sometimes I stick to these guidelines, sometimes I don't. It truly depends on what I'm trying to do.
A model could be built with extremely simplistic features and NOT be very robust at all. Yet I could combine several features into one more complex sketch and end up with a very robust model.
For newer users, PTC encourages making very simple features. I've seen new users make a simple flange that took over 20 features to create. They followed the guidelines to the letter... but the models were garbag. The word "robust" is thrown around without any real definition. Here are a few things I consider important when developing a "robust" model:
- Features and dimensions should capture the design intent of the model including tolerances
- Dimensioning schemes should be meaningful. Dimensions should originate from stable references.
- Build intelligence into your sketches
- Utilize sketcher constraints to minimize duplicate dimensions
- Take advantage of symmetry when possible (and when the design calls for it)
- Make use of construction lines, sketched points, and axis points when possible
- Manage your model tree
- Name features when practical
- Keep related features together
- Selectively use the Group option to collapse the model tree. Name your groups!
- In general, features should be kept simple... however...
- Be careful not to sacrifice flexibility for simplicity
- Refrain from making overly simplistic models to compensate for a other users' ignorance
- Don't be afraid to use chamfers or rounds in a sketch when circumstances merit them
- Make use of patterns when possible
- Minimize the number of features in the model when possible
- Make use of "on the fly" datums and internal sketches wherever possible.
- Document your model
- If you're using relations, add comments to explain their function
- Consider adding Secondary Content to your models in Windchill to document complex model
- Don't be afraid of annotations, parameters, notes, and embedded URLs to help document your model
- Plan/manage your references. Choose stable references for features:
- Name your datums to help explain their function
- Make only the datums you need... refrain from making extraneous datums when a surface will suffice.
- Rule of thumb- select a datum as a reference if available, then a surface, then an edge if nothing else is available (but again, don't go making datums everywhere... this is annoying)
- FLEX YOUR MODEL
- Try changing some dimensions and regenerating. Insure your model won't fail when making reasonable modifications.
- TIP: Use Dynamic Edit to see how your model can flex and change without failure. Back out the changes after you've flexed the model. (Check out the brief video below for a demonstration)
In my opinion, ALL of these factors go into making a robust model. A robust model will flex and update without falling apart. A robust model takes advantage of the powerful features of the software. A robust model is easy to use, easy to understand, and as lightweight as possible. It doesn't use complex features when a simple feature will suffice. However, it also doesn't use 8 simple features when one complex feature could do the job.
Balancing all of these factors is where the art comes in. The skill level of the modeler is always a factor. The best models come from the best modelers. And the best modelers are not created from taking training classes. The best modelers learn their craft by experience... by playing with the software... and by constantly refining their technique as they gather new knowledge.
It sounds very nebulous and certainly much more complex than the simple guidelines you've given in training class. That's because it is. Surely anyone with a set of paints and a canvas can slap down some shapes and colors and call it art... but a true artist paints using specific tools, colors, and techniques to create his work. Modeling in Creo is no different... there's definitely an art which takes time to learn and appreciate.
But... that's just my opinion. 
Regards,
-Brian
Whoa... LEGACY mode!!! I'm totally envious that I didn't think of that first. Legacy mode always available when you need to step back in time a bit. What a tremendous solution...
Aries Chen from the top rope... flattens everyone and solves the problem.
If this works (no reason to assume it doesn't) this is huge.
Thanks Aries!
-Brian
I just had to do 4 sweeps with "Add Inner Fcs" the other day, in fact. It saved me a ton of time. But then, I'm still choosing to use WF4 for my new designs. Unfortunately I've got to do some work in Creo today, so I'll check that out and see how it works.
The idea that it's somehow easier to "complete the model using fill surfaces" is ludicrous. Being able to ad the inner faces like that is great, whereas the "Fill" command is a pain to use. I hate the way you have to go about defining the sketching plane, especially if you have to create a datum on the fly. Ugh......
