generative shape design exercises - naslovnaomk.mas.bg.ac.rs/files/izborni/modeliranje...

Copyright DASSAULT SYSTEMES 2002 1

Generative Shape Design


ExerciseThe Knob

In this exercise you will have the opportunity to model an appliance Knob starting from an empty model.

You will create the supporting Wireframe and build the base surfaces for a quarter section of the Knob.

Next, you will trim, fillet, and perform symmetry operations on these surfaces to obtain the complete Knob.

You will then perform a Draft analysis on the surfaces to determine if the Knob can be extracted from a mould.

In order to obtain a 4 Degree draft, you will modify a supporting line segment and will see the automatic propagation of this change through to the final Skin.

Finally, you will see how to work in a Hybrid environment by creating a Solid by offsetting the Skin.

A completed model “Knob_Completed.CATPart” is available for reference.

60 min.


Design Intent: The Knob

Fillet varying from R=20 mm. to R= 10 mm.

R=5 mm. Fillet all around

4 mm. Thickness4 Degrees Draft (Inside and Outside)


Design Process: The KnobGenerating the

Wireframe

1

Extruding basic surfaces

2

Performing operations : Trim, fillets, and

symmetry

3Offset a solid

4


Exercise

The Knob (Step 1): Generating the Wireframe

In this step you will sketch and constrain the wireframe geometry that will support the surface.

10 min.


Do It Yourself (1/3)

Using the ZX Plane as Support, draw on the fly a quarter circle with R=64 mm, centered on the origin ; as shown.

Load: Knob_Step1_start.CATPart

Rem. : Do not use the sketcher.

Use the stacking commands

functionality



Using the YZ Plane as Support, draw the highlighted arc on the right at the position shown.

Rem. : Do not use the sketcher.

Use the stacking commands

functionality



Using the YZ Plane, Sketch the line on the right and set all the Constraints as shown.

Save your Part. Call it “Knob_Step1”


ExerciseThe Knob (Step 2): Extruding Basic Surfaces

In this step you will create the basic surfaces for the Knob.

10 min.


Do It Yourself

Extrude the two arcs by 70 mm and revolve the line by 90 Degrees. Save your part. Name it “Knob_Step2”.

Load: Knob_Step2.CATPart


Exercise

The Knob (Step 3): Performing operations

In this step you will perform the following operations on the Knob:TrimSplitExtrapolateVariable FilletEdge FilletSymmetryJoin

20 min.



Trim the first Extrusion with the Revolution.Split the second Extrusion with the Trim.




Extrapolate the Split “Up to Element” - specify the Trim. Use the “Assemble Result” option.Extrapolate the Extrapolation “Up to Element” - specify the Trim. Use the “Assemble Result” option.Trim this second Extrapolation with the first Trim.



Rotate the part around. Put in a fillet varying from 20 mm. on the left to 10 mm. on the right. Apply a R = 5 mm constant EdgeFillet on the edges shown below.



Perform a Symmetry on the resulting EdgeFillet. Now, Join the two symmetrical parts.Perform a Symmetry on the Join and once again, Join the two symmetrical parts.Save your part as “Knob_Step3”.


Exercise

The Knob (Step 5): Offsetting a Solid

In this step you will see how surfaces are useful for creating complex solids. In this exercise you will specify an offset on the final surface to obtain a solid with a specific wall thickness.

10 min.



Change to the Part Design Workbench.Select the final join and create a 4mm Thicksurface pointing inward.No-Show the open body to see only the solid.Switch the render style to wireframe mode and look normal to the YZ plane. Notice that the offset of the 4 mm Degree drafted wall has resulted in a non-horizontal footprint for the knob.




Perform a Split on the solid using the XY plane to take off the excess.Add a material – Rubber – and switch to the Customize Render Style.

Reference model : Knob_End.CATPart

generative shape design exercises - naslovnaomk.mas.bg.ac.rs/files/izborni/modeliranje...

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