Recommended Best Practices in Pro/ENGINEER These are RECOMMENDED and not required. You do not have to follow them to the letter. Suggested techniques discussed in this document will help in creating stable models and assemblies and will make it easier to fix failures as they occur.

1. Always start with a plan Before you begin have a modeling plan or strategy in mind. This plan should include the design intent of the model. It is not necessary to have the plan fully developed before you begin. It is, however, very important to have a plan. The plan will undoubtedly change as the project matures. This is precisely why a preliminary plan is so important. It will be very easy to change the wrong plan into the right plan. It will be very difficult to change no plan into the right plan. Create features individually by not creating what should be multiple features as one feature. Example: When creating a shaft with flanges and grooves create the base shaft as one feature and each flange and groove as separate features. The idea is to be able to suppress any combination of features. If the model is created as one feature you are doomed to an all or nothing scenario. Example: Do not sketch multiple closed sections in sketcher. Each closed section should be a separate feature. Create only Parent/Child relationships that are necessary to the model design intent. Whenever you create a feature you MUST be aware of what you reference to constrain that feature. This is not optional. Whenever you are picking a reference do so in a 3-D view. This will make it easier to see exactly what you are picking. Always keep an eye on the message window. The message window tells you what you have picked.

2. Sketcher

a. Use sketched centerlines and construction circles to help you achieve the desired dimensioning scheme.

b. If possible always use REPLACE (Under Edit); instead of deleting a sketched entity.

i. Note: even if you have not referenced a sketched entity that you want to change

someone else (working in Pro/ASSEMBLY, Pro/PIPING Pro/MANUFACTURE, etc.) might have a reference to that entity.

ii. Note: REPLACE will give the new entity the same entity id number as the old entity.

This will result in rerouting all the children of the old entity to the new entity.

c. Keep the number of dimensions in a section down to eight. If you need more than eight use a datum feature to help layout the feature first then reference the datum feature when you are in sketcher. This technique will result in a robust model as well as eliminate future battles with the sketcher.

3. Use layers

a. In part mode use default layers which have been established in the default start part to automatically put various feature types on specified layers.

4. Checklist to Good Pro/Engineer Models:

a. Standard datums. b. Standard views: (correct orientation). c. Layers: (correctly shown and blanked datums etc.). d. Delete suppressed features before submitting to PDM system. e. Assign descriptive names to features in the Model Tree where possible. f. Proper Units systems: (inch/lb/sec). g. Similar features compacted: (patterned/repeated features - grouped). h. Parameters entered. i. Standard relations (if needed). j. Input Correct Density or Material (not required but could be useful). k. Correct Part Numbers/Titles.

5. Basic guidelines for a good part model

a. Features shall be created such that another user can readily modify them at any time. i. This can be accomplished by:

1. Following the standards laid out in this and other Pro/Engineer guidelines. 2. Using the Standard Start Parts when beginning a new part. 3. Consciously setting up your feature parent/child relationships. 4. Create a simple base feature. 5. Create simple sketches. 6. Don't sketch rounds or fillets. 7. If possible use default datums for sketcher view orientation. 8. Don't add material to just to cut it off. 9. Align sketches to surfaces whenever possible. Do not to use edges if it is

possible. 10. If you use the menu "use edge" to create a sketched entity, unalign it from

the edge and realign it to a surface. 11. Add and descriptive comment relations. 12. Dimension the part as needed in order to ease the use of Show True

Dimensions. 13. Create drafts, rounds and chamfers last.

6. Guidelines for New Drawing Creation a. No errors upon regeneration. b. No erased views in drawings, delete unused or unneeded views. c. Relate draft entities to views, check for detached text. d. Make sure views do not overlap. e. Use only named views in the drawing created from datum planes in the model. f. Check for line width and text size uniformity. g. Delete all unused "set models" from drawing dataset. There is no need to create extra load

1

DOCUMENTATIONHELPFULHINTS

Standards ThepartnumbermustberequestedfromDocumentationControl. ThepartnumberneedstobeloadedintheAS400beforeitisreleased PartnumbersshouldbeintheStrykerInstrumentstendigitformat. ThenextassemblypartnumbermustberequestedfromDoc.Con. AlltitlesshouldmatchincludingAccess,AS400,prints,labelsandWindchill

(StartingwithDocumentControltakingoutanumber) Thenamesofanymockassemblies,assemblyrepresentationsusingthesamepart

numberwithunderscores,musthavematchingtitlesandrevisions. Additionaldocumentationcalledoutonadrawing(SOE,QIP,MAP,ES,SK,Items

inAssembly,etc.)mustbereleasedthroughdocumentcontrolandWindchill.Additionaldocumentationmustbeatcurrentrevisionandaccompanynewprints.

AllnewdocumentsmusthaveNONEincludedintheRevBlock. Forreleaseuse05tiOO8forreference. FollowANSIY14.5M1994standardsseedocumentcontrolforreference. FollowStrykerdraftingstandardsanduse05tiOO3forreference. MustbeoncorrectandcurrentStrykerform.

o 05FM005,PurchasedComponentsSpecificationFormato 05FM006,StandardPartSpecificationFormato 05FM009,PackagingSpecificationsFlexiblePackagingo 05FM010,PackagingSpecificationsRigidThermoformso 05FM011,PackagingSpecificationsSecondaryComponentso 05FM017,RawMaterialSpecificationFormato 05FM035,CompressionSpringSpecificationo 05FM036,TorsionSpringSpecificationo 05FM100,ProductComponentDrawingFormato 05FM101,ElectricalComponentDrawingFormato 05FM034FixturePurchasedComponentSpecificationo 09FM108MechanicalFixtureSpecification

Views Alldetached,nonprojectedviewsmusthavephantomlinesaroundthemexcept

Isometricviews AssemblyprintBOMsshouldreflectthepartsthatareactuallyintheassemblyand

viceversa. TheProEassemblymodelBOM,thedrawingBOM,Windchillhierarchyandthe

AS400BOMallmustmatch Drawingviewsshouldonlyreflectgeometryofthepartorassembliesmodel(do

notfakeinedges,crosssections,etc.).

2

Donotcosmeticallyenhancemodeledgesthroughcreationofdrawinggeometry(buildallnecessarygeometryintheparametricallycontrolledmodel).

Donotcosmeticallyeraseedgesoutofviews.Doappropriateenvironmentsettingperviewtoachievedesiredresults.

Centerlinesshouldbeshownforpartsorassemblies,(Show>Axis). Donoteraseviewsthatarenotneeded(deletetheview).Showndimensionsin

erasedviewscannotbeshownagain. Donotorientviewsbypickinginsignificantpartorassemblysurfaces(usedatums

1,2,or3).Theviewmaybecomeinvalid.

Notes TextshouldbeinALLCAPS(exceptions:standardcalloutabbreviationsexample:

mm). TextheightofnotesanddimensionsonBSizeprintsshouldbe.156font

(default). ViewssuchasSections,Details,andOptionalMethodofManufacturingtext

arefontfilled.25.HoweverSCALE:NONEis.156font.Scale:Noneisusedwhenviewisnotprojected.

TextheightofnotesanddimensionsonASizeprintsshouldbe.125font(default).

Alltextintablesandtitleblocksshouldbecenteredhorizontallyandvertically.(Exception:AssemblyBomsareleftjustified)

Columntabletitlestextheightshouldbe.25.Allremainingtabletextis.156(default).

Donotuseaperiodonnotenumberswithabox.Notenumberswithaboxshouldgetaperiod.

Notesshouldhave2spacesaftertheperiodbeforebeginningthetext. Allnotesshouldbeinacompletesentence. Notesmustbeinsequenceofevents.

Dimensions Angulardimensionsshouldhavenodecimalplacesunlessotherwisespecified Useparametricdimensionswheneverpossible.UseShow>Dimension. Donotcreatedimensiononthedrawingunlessabsolutelynecessary.Usemodel

dimensionsmadewiththedesignintent. DonotusethewordPlacesuseanXwithnospacebetweenthenumberandtheX.

(i.e.3X) Alltolerancesshouldbeinlimitformat. Thefollowingitemsshouldalwaysbeabbreviated

o Typical TYPo Continuous CONTo Radius Ro SphericalRadius SR

Rediscovering "Good Modeling Practices"

Just recently I read a short article in Design News about the merits of properly choosing model references. The article (scanned here for reference) talks about this "new" way of increasing effectiveness of CAD. Although they emphasize the value of datum planes, in Pro/E the same is true using any stable reference -- a base feature, datum, curve set, etc..

I chuckled as I read the article because, like a new revelation, the author was saying, in effect, that choices in how a model is created make a difference in how easy it is to manipulate and extend its use.

It's a good piece and it says the truth. I chuckled only because PTC used to (very past tense) emphasize the value of "good modeling practices". Now, (present tense) with Wildfire, PTC has gone the other direction by making choices for you in selecting references and seem to care only that you can make features with fewer mouse picks than with Solid Works. The truth is -- this type of modeling is sloppy and like the article points out, reduces both efficiency and ROI (Return on Investment).

So, This months Tip (Or perhaps better stated, this months Reminder): Use modeling techniques that enhance the usability and robustness of the model. As you work, think about how easy or difficult it will be to manipulate for the next ECR (Engineering Change Request -- or whatever your company calls it), and take time to choose good, stable references that reflect design intent. Page 1-2 in your book. You must constantly ask How could this change, and what could change with it?

There are no hard and fast rules for good modeling, rather a bunch of guidelines because there are always circumstances that change the relevance of the rules.

For reference, here is a quick list of guidelines. The list is by no means complete, but contains some of the big things that will make a difference in the usability and robustness of the typical model:

1. Carefully choose references. This includes references for sketching planes, sketch orientation, sketcher references, edges or surfaces for rounds, etc..

2. Choose references that follow the design intent. Though it's easy to make all your features reference only the base datum planes, the model won't follow when modifications are made. Choose references that allow the model "move" with the intent as changes are made. (In Practice: Don't just accept Pro/E's automatic references (especially in Wildfire). Think about the design intent and choose references that are stable and reflect that intent. Wildfire is horrible about automatic references. Unless you're sketching on a default datum in the assumed orientation, automatic references are rarely applicable or appropriate. So much for minimizing mouse picks.)

3. Choose references that won't disappear. References like edges that disappear when rounded, are not usually the best choice. Datums and planner surfaces are typically better. References from base features are typically more stable than those of later ones. (In Practice: Pro/E provides different methods of selecting references that give similar results, and some are more stable than others. For example, surface selection by Surf & Bnd, or Loop Surfs when selecting for draft (and other times). Select using Intent Chain (May 2002) for edges. These are just a few examples. Choose the best method for your application.)

4. Choose references sparingly. More references mean more feature interconnectivity which can make the model more difficult to work with. However, choose enough references to make the model follow design intent. (In Practice: Some models are so tightly tied with references that the model fails with almost any modification. (August 2002) Users wonder why Pro/E is so hard to work with, but in fact, it's the way the model was constructed. Choices like Thru Next have no references.)

5. When several features are to reference the same thing (like a planner surface or axis), create datums for control. (June 2001) (In Practice: Key datums (planes, points, axes) are easier to find and select when they are named. Named features also denote significance for someone changing the model later. Name your important datums.)

6. When several aspects of a part must interact (like cuts and protrusions to allow wall thickness and spacing) build control features like curve sets to manage the interactions, then reference them with the features.

7. Create relations that associate features when direct references are not practical. (In Practice: When writing relations, use comments for "what" and "why". If other people use the model, they'll be more impressed if you are specific in your comments.)

8. Drafts and rounds are often best left to the end of the model. Although this is a good rule, there are times when they are required earlier. Care should be given to where the features are inserted in the model tree.

9. Rounds should normally be inserted as round features rather than put in a sketch. Again, this is a good rule of thumb, but there are times where a round can't be created or a dimensioning scheme (design intent) requires the radius in a sketch. As above, carefully consider when. (The same is true for Drafts, Chamfers, etc.) (In Practice: It is often good to build models without drafts and rounds, then go back using Insert Mode to put them in -- where possible clustering them with the parent features.)

10. When the above guidelines don't make sense, carefully consider your options. (In Practice: Good modeling practices are far more important early in the model than at the end when you're trying to put in the last round or draft.

Does all this seem silly when you're under the gun to complete a design?

I can see the reasoning. However, I can say from experience, it pays. I have done several projects that, a year or two later came back for upgrades for the next generation. For one particular project, 6 weeks of work went into the first generation, but it took only 4 days to completely re-build (with pretty drastic changes) models for the next generation. For the most complex part, with the extent of the changes to the first few features, I was amazed that the model would regenerate the next 740 features with so few areas having to be rebuilt. Yes, there were rounds, drafts and other things to be rerouted or redefined, but most of the model regenerated perfectly. Truly it paid off for that customer.

Make it pay off for you.