1. PC-DMIS Introduction to GD&T Selection
Joe Zink

2. Introduction to GD&T Selection --- Definitions
PMI:
Product and Manufacturing Information conveys non-geometric attributes in 3D computer-aided design (CAD) systems necessary for manufacturing product components and assemblies. PMI may include geometric dimensions and tolerances, 3D annotation (text) and dimensions, surface finish, and material specifications. PMI is used in conjunction with the 3D model within model-based definition to allow for the elimination of 2D drawings for data set utilization.
Names of PMI Annotations:
Text PMI Roughness PMI
Datum PMI GD&T PMI
Dimension PMI Flag Note PMI

3. Introduction to GD&T Selection --- Definitions
Geometric dimensioning and tolerancing (GD&T) is a system for defining and communicating engineering tolerances. It uses a symbolic language on engineering drawings and computer- generated three-dimensional solid models that explicitly describes nominal geometry and its allowable variation. It tells the manufacturing staff and machines what degree of accuracy and precision is needed on each controlled feature of the part. GD&T is used to define the nominal (theoretically perfect) geometry of parts and assemblies, to define the allowable variation in form and possible size of individual features, and to define the allowable variation between features.

4. Introduction to GD&T Selection --- Definitions
FTA:
Functional Tolerancing and Annotation is a CATIA v5 tool to add GD&T to a part model. Some use FTA synonomous with GD&T. Here is an FTA annotated part from the CATIA v5 workbook on FTA.

5. Introduction to GD&T Selection --- Definitions
MBD:
Model-based definition (MBD), sometimes digital product definition, is the practice of using 3D models (such as solid models, 3D PMI and associated metadata) within 3D CAD software to define (provide specifications for) individual components and product assemblies. The types of information included are geometric dimensioning and tolerancing (GD&T), component level materials, assembly level bills of materials, engineering configurations, design intent, etc. By contrast, other methodologies have historically required accompanying use of 2D engineering drawings to provide such details.

6. Introduction to GD&T Selection --- Definitions
CAD Capture:
A single CAD capture consists of one or more selected CAD elements stored in that capture. Similar to CAD Groups, you can use the CAD Capture dialog box (Edit | Graphic Display window | CAD Captures) to define multiple captures and what CAD to store in each capture. You can also activate or deactivate the CAD captures to show or hide the stored CAD elements within it. It essentially controls the visibility of CAD elements. However, it does more than CAD Groups, because the dialog box can also control the view orientation of each capture, perform a scale-to-fit operation, change the rendering mode, and update the capture based on what's visible in the current CAD assembly, and show or hide clipping planes.
CAD Capture is a term used by our translator vendor. Each native CAD vendor has its own term for this functionality.

7. Introduction to GD&T Selection --- Definitions
Configuration Server:
A database that holds default parameter values for features based on machine mode (manual, DCC) and sensor type (touch, scan).
Replaces the .ipd files (e.g. default.ipd, VoidDetection.ipd)
User can create / modify his own default parameter set via the Measurement Strategy Editor (Edit | Preferences | Measurement Strategy Editor)
This database will expand in future versions and may handle:
other command types (e.g. constructions, dimensions)
probes
machines

8. Introduction to GD&T Selection --- Definitions
Characteristic ID:
In an NX CAD model entities have an identifier called a Characteristic ID. PC-DMIS has a separately licensed option that works with GD&T Selection that names features and dimensions based on its Characteristic ID.
This means that the dimension names in the report directly correlate to the CAD model allowing the user to quickly compare his measurement results to his design data.
In this example the Characteristic ID is 46 so the surface profile command is named 46 and it’s patch scan command is 46.1.

9. Introduction to GD&T Selection --- Definitions
DCI:
Direct CAD Interface means that PC-DMIS connects directly to the native CAD system (NX, CATIA v5, Solidworks, Pro/E). Information flows directly between the two software packages with no translation required.
DCT:
Direct CAD Translator means that PC-DMIS uses a third-party translator to convert the native CAD format into an internal format.

10. Introduction to GD&T Selection --- PC-DMIS CAD support
CAD Support by PC-DMIS version:
Search for the topic: What CAD systems are supported…

11. GD&T Selection --- PC-DMIS Implementation
Implemented in PC-DMIS v2013
Enhanced in each version since then.
Standard with CAD++. Option for CAD.
GD&T notes can be displayed and hidden in the Graphic Display Window via icon on the Graphic Items toolbar
GD&T notes can be moved via Text Box mode.
GD&T notes can be resized and the font changed via the Font Setup dialog, which is displayed via Edit | Preferences | Font.

12. GD&T Selection --- PC-DMIS v2015.1 Implementation
Select All GD&T
When importing a CAD model into PC-DMIS, either from a DCI or a DCT, if the model contains GD&T, a question is displayed asking if you want to create PC-DMIS commands from all of the CAD GD&T.
If you answer “Yes” all commands required to satisfy each GD&T note on the model are added to the PC-DMIS Edit Window.
This option is also available via the menu Operation | Graphic Display Window | Select GD&T | Select All GD&T.
Is this a complete measurement routine?
Need to at least add a “find part” alignment at the beginning of the measurement routine.

13. GD&T Selection --- PC-DMIS v2015.1 Implementation
Select All GD&T
Optimize Path allows the feature measurement commands to be sorted to reduce path line length.
Optimize Path can optionally add tip changes.
Auto Create Clearance Moves adds between feature drive moves.
Almost “One click” measurement routine creation.

14. GD&T Selection --- PC-DMIS v2015.1 Implementation
Select GD&T in View
All commands required to satisfy each GD&T note in the current view are added to the PC-DMIS Edit Window.
Since CAD Captures (Edit | Graphic Display Window | CAD Captures) can be used to manage the CAD GD&T into groups based on some criteria, like operations, using Select GD&T in View with CAD Captures provides a simple way to create a measurement routine for a specific operation.
Not all CAD models include CAD Captures.
PC-DMIS user can create his own groupings, or captures.
CAD Captures are not required to use this Select GD&T in View function.
This option is available starting with PC-DMIS v via Operation | Graphic Display Window | Select GD&T | Select GD&T in Current View.

15. GD&T Selection --- PC-DMIS Implementation
GD&T Selection via the Graphic Display Window
Activated via an icon on the Graphic Modes toolbar.
Operation
Click on a GD&T note.
Commands are previewed in the Edit Window.
XactMeasure GD&T dialog is displayed.
Click OK to accept command creation.
Click Cancel and commands are removed from the Edit Window.
As a note is satisfied it is grayed out in the Graphic Display Window.

16. GD&T Selection --- PC-DMIS Implementation
GD&T Selection via Box Select
While in GD&T Selection mode, hold down the <Left>-mouse button and drag to “box select” multiple GD&T modes.
The GD&T Selection dialog is displayed with a list of all of the GD&T notes that you have selected.
The “Add” button allows you to select which notes you want to add from the list.
The “Add All” button allows you to add all of these GD&T notes with one click.

17. GD&T Selection --- PC-DMIS Implementation
Quick GD&T
Like Quick Feature, activated via holding down the <Shift>-key.
As the user moves the mouse pointer over a GD&T note, it highlights.
Since changes to the specifications from the CAD Designer are rarely made, this is an easy way to inhibit the display of the XactMeasure dialog.

18. PC-DMIS Introduction to GD&T Selection
Joe Zink