© Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software Who’s Best Practices? Mark Lawry Siemens PLM Software Mark Lawry Siemens PLM Software

Page 2 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software Background: Two user communities in NX Former I-deas users and former Unigraphics (UG) users bring different "best practices" with them, often with strongly held opinions.

Page 3 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software Best practices review Why were they adopted? General design principles? Company or industry standards? Software performance? Are they still valid? Has our design process changed? Have our standards changed? Has the software performance changed? Are new methods available?

Page 4 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 1. Use of datums I-deas practices:  Start with BORN coordinate system (Base Orphan Reference Node) BORN contains 3 planes, 3 axes, 1 origin  Create datums first in the history tree  Create datums relative to other datums UG practices:  Start with primitive block or datum  Don’t create unused datum planes  Create datum planes when needed  Create datums relative to geometry

Page 5 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 1. Use of datums continued… NX changes (from UG or I-deas) that affect old practices:  Datum coordinate systems are now one entity in NX, not separate datum planes.  Unused datum coordinate system planes are not flagged as “unused items.”  Datum coordinate systems can be reordered, even to be the first feature, and associativity added. (This is not possible in I-deas.)  Creation of relative datum coordinate systems (Offset CSYS) has been improved.  Display of datum coordinate systems has been improved to control size.

Page 6 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 1. Use of datums continued… NX best practices:  The BORN coordinate system practice from I-deas is no longer required based on software behavior, but is still a good design practice. It is included in the Model template.  Create other datum coordinate systems as Offset CSYS with associativity to the first datum coordinate system, similar to the BORN method.

Page 7 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 2. Associativity I-deas practices:  Goal to create associative features.  Sketch in Place preferred over sketching on the work plane.  Use Focus to create associative geometry.  Use Feature Copy to subdivide part design.  Use ACF to create associative links between parts in an assembly. UG practices:  Associativity is not the only goal.  Keep features independent because they are less prone to surprises.  Avoid interpart links to prevent inadvertent changes to released files.

Page 8 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 2. Associativity continued… NX changes that affect practices:  Parent/child associativity is very visible in the Part Navigator.  Focus within a part is not required.  Associativity between parts is easier to create without WAVE Geometry Linker or ACF. (NX 6)

Page 9 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 2. Associativity continued… NX best practices:  Build on the oldest, most stable geometry.  Datums should be preferred over faces and edges.  Avoid references to faces or edges of detailed design features like chamfers or blends.  Associativity is most useful in the intermediate design phase with highly engineered models.  For early concept models, it is not as necessary.  Consider using Synchronous Modeling with History-Free mode for concept models or for manufacturing changes, not for highly engineered models. (NX 6)

Page 10 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 3. Organizing sketches I-deas practices:  Sketches are “absorbed” into features.  Convert sketches to reference curves to use in multiple features.  Use sketches to define design intent.  Create as many relationships as possible in a sketch. UG practices:  Sketches are separate features.  Keep sketches simple and small, one per feature.

Page 11 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 3. Organizing sketches continued… NX changes that affect practices:  Sketches can be external or internal to features.  Constraints and dimensions can span from one sketch to another. (You cannot do this in I-deas.)

Page 12 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 3. Organizing sketches continued… NX best practices:  Use the same sketch for multiple features.

Page 13 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 3. Organizing sketches continued… NX best practices:  Reuse sketches and features using Copy and Paste.

Page 14 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 3. Organizing sketches continued… NX best practices:  Use constraints and dimensions between sketches.  Organize design intent in sketches in the most logical way. Sketch 1 Sketch 2 Sketch 3

Page 15 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 4. Sketch-based features vs. form features I-deas practices:  Almost all features are sketch based.  Primitive features are discouraged. UG practices:  Primitive features were used.  Best practice was to only use one primitive to start a model.  Sketched features were avoided by some customers.

Page 16 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 4. Sketch-based features vs. form features continued… NX changes that affect practices:  Primitive features now have some associativity.  Form features now use sketches. (Hole command)  Form features indicate design/manufacturing intent.

Page 17 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 4. Sketch-based features vs. form features continued… NX best practices:  Sketch-based features are still a best practice to define design intent.  Form features offer a better way to indicate design/manufacturing intent in some circumstances.  What is the best way to make the model understandable and editable by others?

Page 18 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 5. “Bushy tree” modeling I-deas practices:  Advanced I-deas users use bushy tree modeling. UG practices:  Users never heard of it.

Page 19 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 5. “Bushy tree” modeling continued… NX changes that affect practices:  In NX, Boolean operations can be embedded within a feature or a added as a separate feature.  The Part Navigator displays features in linear Timestamp order or grouped as solid bodies.

Page 20 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 5. “Bushy tree” modeling continued… NX best practices:  Use a separate Boolean feature to use the equivalent of “bushy tree” modeling. (UG instructors often recommend this, but they don’t call it bushy modeling.)  Turn off Timestamp Order to work with multiple bodies.

Page 21 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 6. Patterns I-deas practices:  Use of patterns is encouraged.  Patterns create one feature. UG practices:  Use of patterns was encouraged (instance arrays).  Patterns created one feature for each instance.  Suppressing individual instances in the pattern was discouraged.

Page 22 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 6. Patterns NX software changes:  Feature arrays and geometry arrays are types of patterns.  The new sketch-based Hole command can create an entire pattern of holes as one feature. (NX 6)

Page 23 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 6. Patterns continued… NX best practices:  Patterns are an efficient way to model, and also capture design intent.  Consider using the new sketch-based Hole command instead of using a pattern command, especially for irregular hole patterns.

Page 24 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 7. Controlling object visibility I-deas practices:  Display Filter is used primarily.  Sketches and tools are absorbed into features. UG practices:  Layers were used primarily.  Company standards existed for layer use.  Sketches and Boolean tools were placed on hidden layers.

Page 25 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 7. Controlling object visibility continued… NX changes that affect practices: There are several methods to control object visibility:  Hide command  Show command  Hide and Show command  Layers  Reference Sets - Used to define what is shown in an assembly.

Page 26 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software 7. Controlling object visibility continued… NX best practices:  Use the Hide and Show command or layers to control object visibility.  Don’t use both at the same time because the Hide and Show command only works with objects on visible layers.  Parts migrated from I-deas will have some objects on specific layers, so you need to know about layers.  Understand Layers and Reference Sets when using assemblies.

Page 27 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software Conclusion NX best practices:  Best practices based on design principles and design intent are still valid. Associativity, structured design, use of datums, reuse of sketches and features  Some best practices based on software behavior are no longer required, but may still be a good discipline. BORN coordinate system  Software changes may open up new best practices. Organizing sketches, using design features, hole patterns

Page 28 © Siemens Product Lifecycle Management Software Inc. All rights reserved Siemens PLM Software Mark Lawry Siemens PLM Software Learning Media Development Mark Lawry Siemens PLM Software Learning Media Development