1. Assembly Modeling Constraints
ENGR 1182
SolidWorks 05

2. Today’s Objectives
Creating assemblies by constraining 3D parts together
Movement and Location dictated by Constraints
SW05 Activity
SW05 Application

3. Assemblies
Assemblies are collections of 3D parts that form one engineering system
Modeled to Fit Together
Location defined by 6 degrees of freedom
3 translational (x,y,z)
3 rotational (about x,y,z axes)
Assembly Constraints in SolidWorks are applied using the Mates tool which positions two components relative to one another.
Assemblies are collections of 3D parts that form one engineering system
The parts are modeled separately to the correct dimensional constraints so that they assemble correctly
The location of the part is defined by 6 quantities
3 translational (x,y,z)
3 rotational (about x,y,z axes)
Mating Features are used to assemble the model
Vertices
Faces
Axes

4. Modeled to Work Together
Compatible Components
Dimensional Tolerances
Assembly Constraints
Operational Requirements
Moving? Fixed?
When parts are originally constructed they must be made according to dimensions
The system is then assembled by adding relations between the compatible components
These relationships are determined by the operational requirements of the system

5. Defining Location
6 degrees of freedom constrain an instance of a part file
X,Y,Z Translation
X,Y,Z Rotation

6. Assembly Constraints (position two components relative to one another)
Coincident
Parallel
Perpendicular
Tangent
Concentric
Lock
Distance
Angle
The bridge example will be used to demonstrate these core concepts

7. Concentric Constraints
Axes of cylindrical features and holes can be selected
Concentric constraints align centerline axes

8. Mating Surfaces
2D surfaces can be mated using the Coincident Constraint to become flush with one another but the correct direction must be given to the computer

9. Additional Constraints
Distance between entities if not flush
Coincident Lines or Vertices

10. SolidWorks Adding Components
Select from the open parts listed or use the Browse to find saved files
In the Assembly tab (similar to the Features tab of a Part file) use the Insert Components button to add part files to this assembly

11. SolidWorks: First Component
INSERTING ADDITIONAL PARTS
ANCHORING THE BASE AT THE ORIGIN
After placing the base part, reopen the Insert Component dialog box and click on the pin to keep the box open. Now browse and double click on or Open the second part and left SINGLE click in SolidWorks window to place second part. Next go to the Insert Component dialog box and single left click on the second part just inserted so that it’s blue high-lighting is removed. Now click on browse and select the third part, left SINGLE click to place it, left click on the third part in the Insert Component dialog box to remove the blue high-lighting and repeat sequence. After placing the last part, select the green check mark or hit ESC to complete the insertion of parts. Note that if multiple copies of any part are needed, one can SINGLE click again after the part has been placed to produce another copy of the part.
The first part inserted will become fixed in space and should be placed at the origin as a base for the assembly.
This must be done by selecting the part and then clicking the green check mark to default to the origin instead of just left clicking in space.

12. SolidWorks Constraints/Mates
In the figure window it will show a preview of the mating and a smaller dialog box will appear
In SolidWorks these are the Standard Constraints used in Assemblies
Change Direction
Confirm Mate

13. The Secret to Successful Assemblies
Move components to be constrained close to each other
Rotate one component so the constrained surfaces or edges can be easily viewed
Zoom in so that the surface or edges are easy to select

14. Verifying that Assemblies are Fully Defined
Before saving your assembly as a PDF using PrtScrn and File/Save As, check that the Fully Defined message appears at the bottom of the display.
Apply the Lock constraint to all rotating parts
Apply the FIX constraint to any Titles (textboxes)
If an assembly is not Fully Defined, using your mouse, “tug” on various parts.
Eventually you will find a part that you can move. From the movement you should be able to determine which Mating constraint(s) needs to be applied to achieve the Fully Defined condition.

15. In the future, all SolidWorks Assemblies homework and exam problems requiring Fully Defined will require the following:
Note that using the LOCK and FIX constraints described above are required in order that the FULLY DEFINED indication described on the next slide will appear if all the proper part constraints have been applied by the student. This process allows both the student and the grader to easily determine if the proper part constraints have been applied.

16. Examples of Fully Defined
Part File - *.SLDPRT
The only Sketch with a minus sign in front of it is the Text Block, so object is FULLY DEFINED
Note that for a Part File, once you leave the Sketching Mode, there is no Fully or Under Defined notation on the drawing.
Assembly File - *.SLDASM
To achieve FULLY DEFINED status, the propeller was “LOCKED” to the generator and if a text box is supplied it must have a “FIX” applied

17. SolidWorks Example http://youtu.be/1s-1CUoq1zE
Assembly of a water filtering pitcher

18. Water Pitcher Start
The first part inserted will become fixed in space and will be placed at the origin aligning the 3 major planes (front, right, top) as a base for the assembly by selecting the part in the open parts list and clicking the green check mark
Origin of Assembly
Origin of Base Part
Aligned Origins

19. Water Pitcher Example: First Mate
Next lets bring in the top compartment and mate the two back surfaces

20. Water Pitcher: Top Compartment
Similar constraints are added to the sides and top ridge in order to fully constrain the top compartment

21. We’ll add a concentric constraint in order to align the axis
Water Pitcher: Filter
Now lets add to our assembly the water filter which fits into the circular hole of the top compartment
We’ll add a concentric constraint in order to align the axis

22. Water Pitcher: Inserted Filter
The bottom ridge of the filter and the top of the compartment are selected and the faces are constrained to be flush

23. Water Pitcher: Section View
A section view can be used in order to see that the mates are correct
Choose the correct plane that cuts through an object

24. Water Pitcher: Sub-Assembly
The top cover of the water pitcher consists of 2 pieces that were put together in a separate assembly and then brought into the current assembly

25. All Constraints applied are located in the Model Tree under Mates
Deleting Constraints
All Constraints applied are located in the Model Tree under Mates

26. Constraints can be selected and removed using the delete key
Deleting Constraints
Constraints can be selected and removed using the delete key

27. Assemblies Wrap-Up
Assemblies – collection of 3D parts that form a system
6 Degrees of Freedom
XYZ Translation
XYZ Rotation
Assembly Constraints
Concentric
Mating Surfaces
Coincident
Distance
Application SW06:
Buck-Eye-Phone
Assembly

28. Activity (SW06)
Create the base of any pinewood derby racer by inserting the chassis (first) and then inserting the axles
Using the pre-made blocks and wheels construct some kind of pinewood derby racer using assembly constraints

29. Important Takeaways
Assemblies are collections of 3D parts that form one engineering system
Assembly constraints are used to locate parts in the assembly relative to each other

30. What’s Next? Due Next Class: SW06 Application
Before next class, you will read about Exploded View and Extracting Drawings and Optional Extra Credit Advanced Assembly Modeling