SolidWorks Strategies for Designing Durable Master Models for Accurate Automation

Robert Mengel, Design Automation Consultant

Paul Gimbel, Business Process Sherpa

Razorleaf Corporation

BACKGROUND

• Razorleaf Corporation SolidWorks Service Partner

Services ONLY (we’re not trying to sell you any products, we’re neutral)

Data Management (EPDM, Enovia, SmarTeam, Aras, V6, MatrixOne)

Design Automation (DriveWorks, Tacton, Custom Programmed API)

Workflow Automation (Microsoft SharePoint and Tools)

• Bob Mengel Mechanical Engineer and Automation Developer/Implementer

• Paul Gimbel (aka “The Sherpa”)

Mechanical Engineer, SolidWorks Demojock, Automation Implementer

All Razorleaf presentations will be available at www.razorleaf.com and on www.slideshare.net

Presentation Focus

Design models that can be automated

Little or no user intervention

Either via API programming or a Solution Partner Product

(for example or )

To Configure or Not To Configure

Issue Configurations Separate Files

Parameters to be driven

Not everything is configurable Separate files with separate feature managers

Model Complexity Suppressed relationships Don’t need it, delete it

PLM Implications One file for many parts Lots of files

Security Easy to make one change that affects a lot of configurations

Once a part is run, put it with the job it was used for (read-only)

Reuse All configurations at your beck and call, no rework

Find or rebuild the part…use automation

Use as reference Configure Component Replace Component

Collaboration Only one user can own a file at a time

Separate files, separate permissions

Configurable Items for Parts and Assemblies

Excerpts from:SolidWorks 2011 SP 1.0 Help File

Two Approaches to Automation

Master Model Generative Model

Start with One model containing “worst case” model

Empty or skeleton model

Control via Delete unnecessary features, mates and components

Add features or components as required

Programming Complexity

Minimal, simply delete components by name

Programmatic mating requires significant efforts

Predictability High, model already exists Suffers from problems due to SolidWorks use of “closest”

Model Testing Model can be tested manually Component insertion cannot be tested without code

Scalable Scales down only Unlimited in size

Step 1: Know Your Audience

• Know what you need to produce

• Drawings

To what level of detail?

What information (notes or dimensions)?

• Models

What features are required?

How much detail do you want to give away?

#1 Mistake in Automation – Too Much Detail

•Do you need threads?

•Do you need swoopies?

•Do you need fillets?

•Do you need hardware?

•Do you need mounting holes?

•Do you even need SOLID GEOMETRY?

Simplified Models and Automation

• Why are you building a model?

• Visualization?

• Model is to it LOOKS right

• Simulation?

• Model it so it WORKS right

• Calculation?

• Model it so it gives you the right result

• Drawings?

• Model it so that the drawings are correct

• To win that SolidWorks model contest?

• OK, fine. Go for it.

Finding and Avoiding Unwanted Parent-Child Relations

• How to find Parent-Child Relations

RMB>Parent/Child shows the feature names, but not what the relations are

What kind of relations are there? Feature vs. Sketch

• Anything that changes can have downstream consequences

Sources of Parent-Child Relationships in Parts

• 1) If you have sub-features, query them first

• 2) In sketches, look for:

Sketch plane reference

Dimension references

Relations (Display/Delete Relations -> External)

Remember that SolidWorks can add relations automatically

Extraneous relations will only cause overdefining if they are in conflict

• 3) In the feature, use EDIT FEATURE

ANY entity selection control could potentially create a relationship

Avoiding Unwanted Relations with Reference Geometry

• Planes and Axes are infinite in size – no failures to intersect

• Cannot be split, cut or have their internal ID compromised

• 2D and 3D Sketches (immune to topological issues)

• Build Reference Geometry at the top of the Feature Manager

• Always consider what might be deleted or suppressed

• Don’t underestimate grandchild and great-grandchild references

Reference Geometry

Uses

Plane End Condition, Sketch Plane, Sketch Reference, Mating

Point Sketch reference, Mating, End Condition

Axis Plane, Sketch Reference, Rotation Axis, Mating

Coordinate System Mating, Export

Sketch Sketch references, Plane location, Axis location, Mating

Top-Down Assembly Modeling (TDAM)

• Key Concept: Relations exist in the context of the ASSY

“Sketch5 in part1 references sketch2 in Part2 AS IT EXISTS in Assy1”

• TDAM has issues when you FILE, SAVE AS because of references

• IModelDocExtension.SaveAs WILL NOT WORK! You must use ISldWorks.CopyDocument

TDAM Limitations for Bottom Up Systems

• Your tools may limit you to single level references

Mating Issues

• Replace Components

Issues with internal identifiers not matching swapped components

Build base references then File, Save As method

• Avoid mates to geometry when you can mate to planes or other ref geometry

• Try using the default datum planes whenever possible

• For complex mating, ask yourself, “Do you REALLY need that?”

Assembly motion

Complex mating schemes for drawing purposesIt looks like you are trying to mate a new component

Mating Generative Assemblies

• Add two entities to the SelectionManager the create Mate entity

The API highly recommends that you use SelectByID2 (mark = 1)

Use NAMED ENTITIES

Make the name identical on the part to be installed

Sketching

• Reduce the number of entities and relations in a sketch.

We’re taught to reduce feature count because it’s faster. What do you care? Your machine is doing the work, you’re probably not even going to be there. Spending an extra 5% or even 15% in rebuild time to gain stability is time well spent.

• Avoid large value changes, they can be unpredictable

See if I can come up with an example of changing from 1 to 2000 that freaks out, but it does not freak out if you go from 1 to 100 to 700 to 1500 to 2000.

• Beware of conditions that have multiple solutions, ex. Tangency.

• Beware of dimensions that may flip.

• Do not rely on negative dimensions, because you can’t always guarantee what direction it’s facing to start with. And you can’t guarantee child dims.

• Minimize external relations. Ex. Multiple references to the same external reference. Make one line coincident to the model edge, then make all of the other relationships to that line.

Automating Weldments

• Sketch lines have direction

Your profile will be attached at the start point

This could mean that your section is flipped if you’re not careful

• Design your profiles to make origin the attachment point

You can use IStructuralMember.LocateProfilePoint = SketchPointObject if you are doing this from scratch, but it’s work to get the sketch point

Most DA tools don’t provide the ability to specify the profile point

• Use reference geometry for trim faces

Automating Sheet Metal

• Issues that face sheet metal automation

Creating invalid geometry (unable to flatten or crashing flanges)

Bending multiple entities per feature

Driving materials and bend calculation method

Normal Cuts

Automating for Drawings

• Notes in the drawing or in the title block

Drive the notes with model custom properties

Automating for Drawings

• Dimensions in the drawing

Make sure that the dimensions are in the model

Make sure that any reference dimensions are to persistent references

Automating for Drawings

• Drawing views

Make sure that named views are identical on swappable components

Make sure any references exist (detail, section views, etc.)

Automating for Drawings

• Sketches

Consider sketch geometry that you want to show on the drawing

Group the entities so that they can be easily displayed/hidden

• Hide Dangling Annotations Option (in Gargantua the MegaDialog)

Automating for Simulation

• Master model method expands to simulations

Create master design studies

Entity selection for adding loads and boundary conditions is tough

Create extra loads/BCs or extra studies – “worst case” approach

External References Of Another Kind

• References to entities outside of your tool must exist or be accessible

Libraries of standard parts

Weldment profile files

Material Library Files

Anything in Gargantua>System Settings>File Locations

• Consider user customizable settings

Users like to customize their settings in Gargantua

This can complicate entity selection

This can alter what is defaulted

This can introduce dialogs that may not appear on your system

Brute Force Method

• We’re engineers. We WANT the elegant solution. Brute force is ugly. It’s inefficient. Well, you’re only being inefficient once. The computer is doing the work the rest of the time.

• Create five separate features and control them all rather than making one megalithic feature that has additional levels of complexity

• Insert multiple options and delete the ones that you don’t need instead of swapping or trying complex drives

• If your automation tool is creating one model, what’s it to your machine if it creates more than one? Consider models specialized for different purposes. One detailed one for manufacturing, a simplified rep for sales, a pretty one for animation and 3DVIA…

Testing

• Test extremes in values

• Keep in mind that your master model will always reside in the same principal state. So your changes must drive from there. Changing from 1 to 10 to 30 to 90 is not the same as testing those four values separately.

• Test value pairs. Changing one dim may not cause a problem. Changing two dims in opposite directions may.

• Always reset your model after testing.

Thank You

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For the complete version of the presentation, including presenter notes, full code and models, visit www.razorleaf.com after the show! Yes, it’s free.

Sauteed Fillet of Atlantic HalibutSunchokes, King Trumpet Mushrooms, Watercress and “Sauce Genevoise” from Thomas Keller’s French Laundry