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Note: This article is based on Ron’s 2003 PTC/USER World Event presentation, which conference attendees voted as Best Overall.
This presents several concepts and techniques that can help you be more productive when modeling high feature-count models. While most users are familiar with the ideas covered here, the trick is to implement a methodology that helps to put all of the pieces together. I would liken the results to hearing a fully orchestrated song rather just individual instruments.
Being organized takes discipline and practice. While some of these techniques may seem to take a lot of time up front, they will pay large dividends in the end.
The foundation for model organization starts with creating and using company best practices. What you are trying to achieve with these best practices is a clearly defined and organized model. This concept means that all models must contain certain things. Once you establish your best practices, make sure that both internal users and contractors who work for your company apply them.
Figure 1. Document your best practices and make them widely available
While a complete list of best practices is beyond the scope of this article, here are a few to get you started.
Template and Start Part Files
All sorts of standards can be accomplished with these files. They give each part consistency no matter who creates the file. A few examples are:
- Pro/E parameters used in drawings, Pro/INTRALINK, and other functions
- Standard relationships
- Units
- Layers
Standard Layers
Organizing your model is very important. You want common layers for items such as datums, rounds and drafts. This enables all users to easily adjust the viewing status to individual needs
- Use standard layer names
- Apply layer properties for feature type assignments
- Predefine the blank status for layers
Part Features
When modeling, the outcome is more than just a design. A good model contains features that allow anyone to make modifications. Here are some suggestions to make that happen.
- Avoid suppressed features. Suppressed features may be confusing and cause problems if they are resumed. (This rule may not, however, apply to parts with family tables.)
- Keep features organized in logical sequences. (More about this later.)
- Keep feature parent/child relations organized. (This is extremely important)
- Keep drafts and rounds at the end of you model when possible.
- Use intent features when possible.
- Know your depth options, use through next instead of up to surface when possible.
- Avoid geometry checks.
- Make use of draft check on molded parts that require draft.
- Know your pattern options and when best to use them.
Assemblies
It’s just as important to control assemblies as it is to control parts. Assembly best practices will help ensure that components and assembly features do not fail.
- Avoid suppressed components. (Family tables may override this rule.)
- Avoid frozen, unplaced or packaged components.
- Avoid ghost objects (caused by external references to models that no longer exist) for Pro/INTRALINK.
- Be sure to run a global interference check.
- Develop standard simplified reps.
Data Management
While the information presented here assumes you use Pro/INTRALINK, most of these rules apply to any data management system.
- Establish standard file names.
- Designate parameters for descriptive fields.
- Develop custom searches (Pro/LOCATE).
- Enforce authorizations (who has access to what).
- Implement a revision-tracking scheme.
The next step to greater productivity is to have an organized model. Once your standards are in place, it’s time to leverage them to help you work more efficiently.
Know your feature relationships.
Of all the best practices you might have, managing your parent/child relationships deserves special note. Poor reference control is one of the most common obstacles to productivity. I have seen model after model that cannot be drafted, modified, or redefined because of poor management of parent/child relationships. While I will offer some tips on how to help control unwanted relations, due diligence is the true key to successful modeling.
Figure 2. Keeping good feature relationships is imperative.
Keep features organized in a logical sequence.
A model feature is usually made up of a number of Pro/ENGINEER features. For example, a boss may be made from six features. All of these features should be in numerical order in the model tree. Say that the first of your features is number 11. In this case, you should find these features in order from 11 to 16. By keeping features grouped this way, you can suppress and resume them much more efficiently.
As you group your features in order, watch out for your feature relations. In most cases, you should be able to suppress and resume a set of features without having to also suppress or resume “unrelated” features.
Figures 3a and 3b. Keep a group of features in numerical order.
Assign features to a layer.
By adding features to a layer, you can use that layer assignment to select features to suppress and resume. (More on suppressing and resuming a group of features below.) Be sure to give the layers logical names that describe the set of features. These layer names are in addition to your standard layers.
Figure 4. Assigning features to a layer assists with suppressing and resuming functions.
Create “marker” features.
In the quest to keep features organized, it is helpful to know where the group of features starts and ends. The start is usually a no-brainer. When you start a new set of features, the first one is most likely to be the parent of the rest. It’s helpful to give that feature a name indicating it is a start of a set of features (e.g., start_boss).
The end of the set is a bit trickier. While it may be easy to name the last feature, what if you need to change the model and add more Pro/ENGINEER features to the set? To avoid multiple renames, I create what I call a “marker “ feature. I use a simple point because it regenerates quickly and is easy to create. I name the marker feature to indicate the end of the feature set. In this example, it would be end_boss. This marker feature becomes an important tool when you start to redefine or modify your model.
Figure 5. Use markers to help identify a grouping of features.
While working on a large feature-count model, people often want to modify a feature. Sometimes, there are several dimensions or it might take several attempts to get the correct geometry. I often see people make changes to feature 100 and then wait for another 500 features to regenerate, only to see that the change is not correct. They repeat this process several times and find out that a simple change takes a very long time.
If there are a number of features down stream from the modifications that have to regenerate, I use insert mode before I starting the modifications. By inserting close to the desired geometry, I avoid regenerating features that have no real bearing on what I am to do. The model then regenerates quickly for the specific changes. After the modification is done, I then resume the rest of the features.
You can also use insert mode when adding more features. Going back to the example off the boss, I will insert right before my marker feature indicating the end of the feature sequence. This way, I keep my features in a logical order. When inserting new features, remember to add them to your feature layers. (See Assign features to a layer section above.)
Generally speaking, you don’t need all of the features in your model all of the time. I recommend that you suppress features that you don’t currently need. This also keeps your parent/child references in check. If the features are suppressed, you cannot build unwanted relationships. It also reduces repaint and regeneration times.
I previously suggested that you place feature sets onto a layer. When suppressing and resuming features, having features on a layer becomes very handy. In Pro/ENGINEER 2001, you can use the Feature, Suppress, By Layer and Resume by Layer options. In Wildfire, you can use the search tool or layer tree functions to accomplish this. By assigning a group of features to a layer, you can easily suppress and resume only what you need.
Figure 6a. Working with all your features active slows you down.
Figure 6b. Suppressing features that you don’t need increases your productivity.
It’s easy to waste lots of time orienting and reorienting your model. I see people going through the motions of zoom, zoom, pan, rotate, zoom and pan to get the view they want. As soon as the modeler gets into sketcher mode, though, the orientation is easily lost. Once out of sketcher, they attempt to get back to that same orientation using the same old process.
What I recommend is creating saved views. If you are working on a particular area on your model, you will most likely get an orientation that best suits your needs. Why not save that view so that you can get back to it easily?
I also create mapkeys that save and retrieve these views. I have four saved views (named V1, V2, V3 and V4), and use mapkeys to save an orientation to the particular view and others to retrieve the orientations. Since these are “working” views, I change them to suit my needs. (For more details on this technique, see my previous article, Using Saved Views, available in the tips section of profilesmagazine.com.)
Figure 7. Saved views reduce reorient and repaint times.
Hopefully, you can use these ideas and methods to reduce the time you spend on modeling. If you watch what you are doing and find areas that just seem to take too long, take a good look at what you are doing and try to develop an approach that minimizes this behavior. As you do this, you can work smarter and not just harder. 
Ron Grabau is a mechanical CAE engineer at HP. He can be reached by email at ronald.grabau@hp.com.
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