3D Design & Practices

3D Design & Practices Presented by: Bill Samuels Designer BAE Systems 2008 FIRST Robotics Conference

45 minutes on these topics • General Design Process • 3D Modeling Philosophies • Best Practices in Pro/ENGINEER • Tips and Tricks for Pro/Engineer • Web resources, Cool Links & Acknowledgements 2008 FIRST Robotics Conference

General Design Process • Define the Task • White board • Documentation • Prototype • Peer Evaluation • Team Design Reviews • Build 2008 FIRST Robotics Conference

General Design Process Define the Task Defining the task establishes a clear goal or goals. Do not confuse defining the task with a solution for the task. An example: A pencil and a cup resting on a desk, the task is to get the pencil in the cup. A solution would be placing the pencil in the cup using your hand. Using the expression placing the pencil in the cup limits the designer to thinking that only the pencil is allowed to move. Keep this list of goals and or tasks as generic as possible, this allows free thinking. 2008 FIRST Robotics Conference

General Design Process White board In conjunction with the discussion of defining the task, white boarding thoughts conveys information not easily expressed in words. This is also a great place to capture tasks that will assist in keeping the group focused. 2008 FIRST Robotics Conference

General Design Process Documentation During the discussion and white boarding session it is very critical to document all information in an engineering notebook. This assures that data and progress will not be lost between sessions. A team scribe is recommended. 2008 FIRST Robotics Conference

General Design Process Prototype Once tasks have been defined and solutions considered, it is time to prototype the solutions. This can be done using pencil and paper, 2D & 3D CADD tools, and prototype/real world mockup. 2008 FIRST Robotics Conference

General Design Process Peer Evaluation A peer evaluation can be as simple as asking the person next to you to take a look at your design and give their thoughts. Peer evaluations should happen on a daily basis, this affords a second set of eyes a chance to capture design flaws and possible oversights. 2008 FIRST Robotics Conference

General Design Process Team Design Reviews Once the possible solutions have been captured and critically evaluated, it is time for a team design review. This review should explain the choices made and recommendations for the final design. 2008 FIRST Robotics Conference

General Design Process Build Once the team has committed to a solution for the task it is time to build. Once building has begun the team may find issues with some of the sub assembly designs. This will require going back and modifying some of the design concepts agreed upon in earlier design phases. This is when the design process would start over for that sub assembly, repeat as required until a complete solution is attained. "Once you have a good idea (design), stay with it. Dog it. Work with it until its right!“ - Walt Disney 2008 FIRST Robotics Conference

3D Modeling Philosophies • Top Down Design • Bottom Up Design 2008 FIRST Robotics Conference

3D Modeling Philosophies Top Down Design In top down design concept a top assembly envelope is cut into specific volumes. These volumes are assigned specific functions. In this philosophy a specific sub assembly does not limit the top assembly’s progress. Nor does it require any specific sub assembly to be completed first. This does require a lead designer to be responsible for maintaining volumes for sub assemblies and there locations and progression in the top assembly. 2008 FIRST Robotics Conference

3D Modeling Philosophies Bottom Up Design In bottom up design concept sub assemblies are added as they are completed and no specific area is reserved for sub assemblies. This requires a lead designer to be responsible for maintaining the top assembly and insure he has the latest data from each designer. 2008 FIRST Robotics Conference

3D Modeling Philosophies Choice of Philosophy Both of these philosophies can work very well, as long as the entire team adopts the same philosophy. And just as important is that everyone on the team assists the lead designer in capturing the loose ends. One of the biggest pit falls is trying to combine the two philosophies. And the biggest pitfall is not being proactive about resolving issues you aware of. If its not clear to you how a component works, ask. Not asking usually leads to lost work hours, over filing and a stressful environment. 2008 FIRST Robotics Conference

3D Modeling Philosophies Part modeling philosophy Just as in an assembly a part can be top down or bottom up. In top down for a part you start with the smallest mass that will encompass the whole part and remove material to add definition. In bottom up you start with a core shape and add features to complete the definition of the part. 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER • Always start with a plan • Create Features Individually • Create Features in a Logical Sequence • Carefully Create Parent/Child Relationships • Use Insert Mode • Use Layers • Guidelines for Good Sketcher Use • Checklist for Good Pro/Engineer Models • Guidelines for a Good Part Model • Guidelines for Good Drawing Creation 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER Always start with a plan It is very important to have at least a preliminary modeling plan or strategy in mind before modeling. This plan should include the design intent of the model. Since the plan will undoubtedly change as the project matures, it is not necessary to have this plan fully developed before beginning. It will be very easy to change the wrong plan into the right plan but be very difficult to change no plan into the right plan. 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER Create Features Individually Do not create one feature that should be multiple features. This will allow any combination of features to be suppressed or deleted. Do not sketch multiple closed sections in sketcher. Each closed section should be a separate feature. For example: When creating a shaft with flanges and grooves, create the base shaft as one feature and each flange and groove as separate features. If the model is created as one feature, there is an “ all or nothing” scenario. 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER Create Features in a Logical Sequence For Example: A cover may require 4 features to model correctly. If the cover is to have a lip around the top then the clearance holes for the fasteners that hold down the cover may have to come after the lip feature. 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER Carefully Create Parent/Child Relationships Create only the Parent/Child relationships that are necessary for the model’s intent. Whenever creating a feature, always clearly identify the references used to constrain that feature. Whenever picking a reference, do so in a 3-D view. This practice will make it easier to identify exactly what is picked. Read the message window to validate picks, it lists what has been picked. A set of related features should be able to be suppressed and resumed without having to also suppress or resume unrelated features. 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER Use Insert Mode Use Insert Mode before modifying or when adding features. Especially when working on a model with complex geometry or a large feature-count. By inserting close to the desired parent geometry, regenerating features that have no real bearing on the modification is avoided and the model regeneration time is reduced. When adding features, it will keep features in a logical order and keep parent/child relationships in check. After the modification or addition is done, resume the rest of the features. 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER Use Layers Use default layers to automatically put various feature types on specified layers. To verify that these default layers are set for the part being worked on, either use the Layer menu in the Model Tree or verify the layer setup in the Config.pro file. The Layer menu will display the default layer options that have been activated. If any of the default layers listed is not activated, do so by editing the table. Create additional layers with logical names that describe the features assigned to it. They can assist in suppressing and resuming features. Keep in mind the top assembly has every layer of every part. 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER Guidelines for Good Sketcher Use • Use sketched centerlines and construction circles to achieve the desired dimensioning scheme. • Do not allow any weak dimensions to remain in a completed sketch. Either add constraints, convert the weak dims to strong or add strong dimensions to complete a sketch. • As a rule of thumb, keep the number of dimensions in a sketch to a maximum of eight. Where more are needed to fully dimension a feature, create datum features first, then reference the datum features when in Sketcher. This technique will result in a robust model and minimize future difficulties with the Sketch. It also follows the “many simple features” rule to create models. • Choose references sparingly. More references mean more feature to feature relationships that can make the model more difficult to work with as it progresses or changes. Choose only enough references to make the model follow the design intent. 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER • Choose references that won’t disappear. References like edges that disappear when rounded or drafted, are not the best choice. Datums and planner surfaces are better. References from the base features are more stable than those of later features. • When redefining a sketch, use Replace (Under Edit) rather than deleting a sketched entity whenever possible. 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. Note that even if you have not referenced a sketched entity someone else (working in Pro/ASSEMBLY, Pro/PIPPING, Pro/MANUFACTURE, etc.) might have a reference to that entity. 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER Checklist for Good Models • Does it use the standard configuration file? • Have the six standard views been created in the correct orientation. • Has an appropriate pictorial view for the drawing been created and named for easy identification? • Were layers created as needed and correctly shown or blanked for the drawing? • Are descriptive names for features assigned in the Model Tree where possible? • Have similar features been compacted by using patters and groups? • Are Geometry Checks needed (is menu grayed-out) • Have the standard parameters been created and their values been entered? • Have the standard relations been created? • Does it use the proper units systems (inch/lb/sec)? 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER • Has the correct density or material been assigned? • Has the correct file name been assigned? • Has the correct file location for storage, backup and retrieval been validated? • Are assemblies using library fasteners whenever possible? • Have suppressed features been deleted? 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER Guidelines for a Good Part Model The goal is to create and name features so that any other user can readily modify them at any time. Good modeling practices are far more important early in the modeling process than at the end as repair work. Accomplish this by: • Following the standards in Pro/Engineer guidelines • Using the standard Start Parts when beginning a new part • Consciously setting up your parent/child relationships • Creating a simple base feature • Creating simple sketches • Not sketching rounds or fillets when avoidable 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER Guidelines for Good Drawing Creation • Use the standard drawing set-up file • The model should regenerate without errors or geometry checks prior to beginning the drawing • No erased views should be kept in drawings • Relate draft entities to objects or views, check for unattached text ( missing leaders) • Make sure views do not overlap one another • Use only projected, detail, or auxiliary views whenever possible (avoid multiple general views) • Check for line width and text size uniformity (as in standard drawing set-up file) • Use shown dimensions as opposed to created dimensions whenever possible • Delete all unused models from drawing 2008 FIRST Robotics Conference

Best Practices In Pro/ENGINEER • Using default or created datums for view orientation • Dimensioning the part model as needed in the drawing • Creating drafts, rounds, and chamfers as late in the part model as practical • Carefully considering the options when the above guidelines don’t make sense. 2008 FIRST Robotics Conference

Tips & Hints • Ways to impact text • Special Characters in a Note • Color • To Select items • Search Secrets • Dimensioning • Axis Points • View Styles • Pivot Point • Control Alt during assembly of items • Uncheck constraints to allow freedom • Use Lock Dims to assist in relocating items in a sketch 2008 FIRST Robotics Conference

Tips & Hints • Ways to impact text • @s = a dim will display its symbol instead of its numeric value when shown on a drawing. Also seeing “A”, “B” and “C” is better for family tables than seeing d1245, d1342 and d879. • @+ = superscript • @- = subscript • @# = end script change • @o = @o = replace the d with the letter o of the created dimension and enter text, does not work on driving dimensions • @[ = start boxed text • @] = end boxed text • To control the number of digits displayed in a table on a drawing Create relation to “name” = &dim# On drawing use &”name”[.7] where the 7 is the num of digs to display. 2008 FIRST Robotics Conference

Tips & Hints • Special Characters in a Note: review the character map and locate the desired symbol, create a note including the cross-referenced symbols value, change the font that specific sysmbol. 2008 FIRST Robotics Conference

Tips & Hints • Color: Create custom colors by copying existing ones and editing them. 2008 FIRST Robotics Conference

Tips & Hints To Select Items: One by One Use CTRL Edge Loop: Select Edge, Shift – Select 2nd Edge Loop Surfaces: Select Surface, Shift - Select Edge Seed & Boundary Surfaces: Select Seed, Shift – Select Boundary, use control to add last surface. Edge From – To Chain: Select Edge, Shift – Select 2nd Edge, RMB (Toggle) Solid Surface: Select Surface, RMB “Solid Surface” 2008 FIRST Robotics Conference

Tips & Hints Search Secrets: CTRL – F Components Features Name Type Size ID Status 2008 FIRST Robotics Conference

Tips & Hints Dimensioning: NOTE: CONVERT STRAIGHT LINES TO CONSTRUCTION. Perimeter: Entity(s), Convert To, Dimension Tangent Angle: Vertex, Entity, Entity, Place Arc Angle: Entity, Vertex, Vertex, Place Arc Length: Use Perimeter Function. NOTE: CONVERT STRAIGHT LINES TO CONSTRUCTION. 2008 FIRST Robotics Conference

Tips & Hints Axis Points: Available in Internal Sketches only To be used for DimensioningScheme Useful for assemblyreferences and in patterns 2008 FIRST Robotics Conference

Tips & Hints View Styles: Blank, Wireframe,Hidden, HLRBy Display Multiple Styles available at once User Activated Visible Indication Will impact Repaint Performance 2008 FIRST Robotics Conference

Tips & Hints • Pivot Points when copying features in sketcher you can change the pivot point by right clicking on it and then selecting the desired location. 2008 FIRST Robotics Conference

Tips & Hints • Control Alt Use control alt pressed at the same time to orient an item being added to an assembly. Control Alt & RMB to spin the item being added. Control Alt & MMB to pan the item being added. 2008 FIRST Robotics Conference

Tips & Hints • Uncheck constraints to allow freedom Rather than delete constraints, uncheck them to evaluate other locations and orientations of an item. 2008 FIRST Robotics Conference

Tips & Hints • Use Lock Dims to assist in relocating items in a sketch Set filter to Dims, window entire sketch, RMB and hold, select lock. Then unlock the dim controlling the location of the sketch. It can now slide in that orientation without distorting. 2008 FIRST Robotics Conference

Web resources, Cool Links & Acknowledgements www.ptc.com/support Knowledge Base /community Tutorials & Download www.proesite.com Configs & Benchmark www.ptcuser.org Exploders www.profilesmagazine.com Pro/E E-zine www.proengineer.com Pro/E Resources www.mcadcentral.com Tips, Jobs, Forums www.proe.com Tips, Forums www.turbosquid.com/3d models www.mcmaster.com/ vendor items, models www.3dcadbrowser.com models www.3dcontentcentral.com/ models www.mcaduser.com/ models www.gdandt.com/quiz.htm a geometric TOLERANCING quiz www.matweb.com/search/MaterialGroupSearch.aspx materials properties page www.cad-resources.com/ tutorials Everything in this presentation is a compilation of exposure to all of these links and fellow users and their presentations I thank them all for making their knowledge so accessible to me and YOU! I would only ask you pass on knowledge you gain to others as well. 2008 FIRST Robotics Conference

3D Design & Practices