•

Analysis

• FEA• Tolerance

Analysis

Manufacturing

• CNC Instructions• Automated

Manufacturing Plan

Inspection

• CMM Instructions• Closed Loop

inspection feedback

• Reduce costs and reduce number of prototypes needed

• Improve product quality and get to market faster

• A fully defined 3D model captures design intent for use by manufacturing, inspection, and suppliers downstream

• Product development is becoming more complex and traditional methods can limit progress

• MBE begins with building a comprehensive model (MBD)

• Model is the repository for design requirement definitions

• Requirements definitions must be machine readable to realize the full power of MBE

Part No. 12345678

Description Metal Hanger

Material Metal

Company Sigmetrix

Data Rights Confidential

Supplier ACME Manufacturing

3D GEOMETRY PMI ANNOTATIONS ATTRIBUTES

MAY MEAN THIS

25

25

-1

+1

-1

+1

Possibly Creates a 2mmSquare Tolerance Zone

25

25

2mm Wide Tolerance Zone

+1-1

-1

+1

2mm Wide Tolerance Zone

"Axis" of Hole

50 ±1

25 ±1

25 ±1

50 ±1

Ø10 ±0.5

20 ±0.5

What do the dimensions on this drawing mean?

Are we locating the hole to the surfaces?

Are we locating the surfaces to the hole?

• WHAT IS THE REQUIREMENT ON THE PRODUCED PART?

• DISTANCE FROM REAL SURFACE

• DISTANCE FROM ORTHOGONAL PLANES

• DISTANCE FROM TANGENT PLANE

• DISTANCE FROM NEAREST POINT ON THE SURFACE

25

2mm X 2mm Tolerance Zone(Not Square)

25

As-Produced Hole

As-Produced Part25

2mm X 2mmTolerance Zone(Not Square)

As-Produced Hole

As-Produced Part

25

As-Produced Hole

As-Produced Part

2mm X 2mm Tolerance Zone

25

25

As-ProducedSurface

As-Produced Surface

As-Produced Hole

As-Produced Part

As-ProducedSurface

10 20 30 40 50 60

Two-PointMeasurement

Measuring Tape

±1 Tol Zone

Problem is compounded when dealing with real variation

50 ±1

25

25

Ø10 ±0.5

20 ±0.50.2 A

B

0.2 A B

C

2.8 A B C

0.1

A

50 ±1

• GD&T (GPS) CLARIFIES:• THE HOLE IS BEING CONTROLLED RELATIVE TO A

COORDINATE SYSTEM DEFINED BY THREE DATUMFEATURES LABELED A, B, AND C.

• THE ORDER OF PRECEDENCE FOR DEFINING THISCOORDINATE SYSTEM.

• THE ALLOWABLE VARIATION BETWEEN THE DATUMFEATURES DEFINING THE COORDINATE SYSTEM.

• GD&T defines allowable variation for individual features

• Size

• Form

• GD&T defines allowable variation between features

• Location

• Orientation

• Standards based language that defines the limit of variation in terms of boundaries

• Clearly defines what is being measured to what

• Allows explicit control of all aspects of feature variation

GD&T can be difficult to understand and remember all the rules

• Millions of dollars are spent each year in training, books and guides to educate people and refresh the knowledge of GD&T

• Even with this investment retention and understanding is low

Achieving proper syntax and semantic connections is difficult

• Is the callout consistent with my tolerancing standard?

• Are my semantic geometric connections consistent with my callout?

• Are there appropriately associated datum feature for my datums?

• Do the referenced datum features form a proper datum reference frame?

Ensuring complete and proper constraint is difficult

• Have I constrained all the features I intended?

• Have I controlled all the controllableaspects of those features?

• Do I have any redundant controls?

Assigning correct tolerance values is difficult

• Will specified tolerances achieve performance characteristics?

• Are specified tolerances achievable by manufacturing?

• How do manufacturing deviations affect system requirements?

Annotate parts with GD&T Advisor to validate syntax and ensure completeness.

Check performance characteristics within CETOL reusing the Tolerances created in GD&T Advisor

Adjust tolerances values in CETOL to meet objectives

Be confident that your MBD model correctly conveys the desired intent.

• GD&T or GPS is the preferred language for MBD• Unambiguously defines variation control

• As with any new language GPS may be difficult to master• Is the syntax correct?

• Is it complete and consistent?

• Does is convey the correct meaning?

• There are tools available to help increase confidence• GD&T Advisor for specifying tolerances

• CETOL for performing tolerance stack-up

• With confidence comes the power to unlock the potential of MBD