Assembly Modeling Constraints. ENGR 1182 SolidWorks 05

Transcription

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 1. Modeled to Fit Together 2. Location defined by 6 degrees of freedom 3 translational (x,y,z) 3 rotational (about x,y,z axes) 3. Assembly Constraints in SolidWorks are applied using the Mates tool which positions two components relative to one another.

4 Modeled to Work Together Compatible Components Dimensional Tolerances Assembly Constraints Operational Requirements Moving? Fixed?

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 Coincident Lines or Vertices Distance between entities if not flush

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 ANCHORING THE BASE AT THE ORIGIN 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. INSERTING ADDITIONAL PARTS 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.

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

13 he Secret to Successful Assemblies 1. Move components to be constrained close to each other 2. Rotate one component so the constrained surfaces or edges can be easily viewed 3. 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 Assembly File - *.SLDASM The only Sketch with a minus sign in front of it is the Text Block, so object is FULLY DEFINED 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 Note that for a Part File, once you leave the Sketching Mode, there is no Fully or Under Defined notation on the drawing.

17 SolidWorks Example 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 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 Deleting Constraints All Constraints applied are located in the Model Tree under Mates

26 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 Application SW06: Buck-Eye-Phone Assembly Assembly Constraints Concentric Mating Surfaces Coincident Distance

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