Week 8 - Challenge 5 - Core & Cavity Design

Aim: To create the tooling axis for the given Class-A surface of the Switch Bezel and create a solid part along with Class-B and Class-C surface.

Procedure: The input model for the draft analysis is the class-A surface given by the class-A designers as shown below:

Fig. 1: Switch Bezel Class-A Surface

Considering the shape of the given path for initially we will define the tooling axis by the bisecting method. We need to draw sketches and then bisect those sketches to get the tooling axis.

Place a point on the green coloured surface in the Class-A surface and put an axis system on that point. Create the following sketch on the YZ plane.

Fig. 2: Sketch 1

Draw the following sketch on the XZ plane as shown below:

Fig. 2: Sketch 2

Draw a bisecting line to get the tooling axis.

Fig. 3: Bisecting line

This tooling axis and the Switch Bezel Class-A surface need to be accessed multiple times and hence, need to be published. Go to Tools>Publication. These will be published in the feature tree.

Next step is to perform the draft analysis of the part with reference to the Tooling Axis. Go to Insert>Analysis>Feature Draft Analysis. Make sure that the View Mode Customization is set to the Material Mode as shown below:

Fig. 4: View Mode Customization

In the draft analysis toolbar shown below, insert the axis system from the Direction tab and place it over the Tooling Axis such that the ’w’ of the compass is aligned to the tooling axis. Lock the compass in place.

Fig. 5: Draft Analysis Toolbar

Another tool box in the Draft Analysis represents the colour coding of the draft angle of the faces from the

Tooling Axis or the Compass placement. It is shown below:

Fig. 6:Draft Analysis Toolbar

If the angle of a surface is less than the 0deg in this picture, the face will be represented by Blue colour. If the angle of the surface is between the two values shown in the figure, the face is represented in the Red colour and if the value is greater than the highest value, it is represented in Green colour.

After opening this toolbar, click anywhere on the Fan Cover surface. The Draft analysis is shown below:

Fig. 7: Draft Analysis of the Class A Surface

The draft analysis of the solid body is shown below:

Fig. 8: Draft Analysis of the Solid Body

Since the faces are angled at more than 3 degrees, they are shown in Green colour. Click on the 2nd icon under the Display menu and hover over the face, it will display actual value of the draft as shown above.

To make a Class-B surface, follow the steps for every individual surface:

Select the surface and use Extract, Untrim, Extrapolate, Trim and Offset commands to make a surface profile similar to the Class-A surface as shown below:

Fig. 9.1: Class B Surface

In this class-B surface, the fillets should be given such that the thickness of the component is uniform.

To create a Class-C surface, use the Sweep command to sweep the boundary of the Class-A surface along the tooling axis and Trim the surface together to get a closed surface. In the Part Design, use the Close Surface command to make a solid part and save. The orientation of the part is shown below along with the feature tree:

Fig. 9.2: Class C Surface

Fig. 10: Front View of Switch Bezel

Fig. 11: Top View of Switch Bezel

Fig. 12: Right View of Switch Bezel

Fig. 13: Isometric View of Switch Bezel

When this solid part is created, the surfaces are used to create to Core and Cavity Block as described below:

1. The Class-A surface is extracted and Extrapolated in all direction for 15mm.
2. It is trimmed with Class-C surface to get the parting surface with the component area.
3. The Class-A and Class-C were joined during creation of the closed surface. Intersect this join with the Class-B surface to get the Parting line. Split the parting line and the parting surface with component area to get the final Parting Surface.
4. To create a Core Block, create a Rectangle on the XZ plane and extrude it along the tooling direction. Trim this extrude with the parting surface with component area to close one side of the block which will have the profile of the component. Fill the other side and join these together to complete the Core Block.
5. To create a Cavity Block, extrude the rectangle as above and trim it with Class-B surface to close one side of the cavity block with the component profile. Fill the other side and join these to get the Cavity block.

The orientation of the Core and Cavity Block are shown below:

Fig. 14: Sketch to extrude Core and Cavity Blocks

Fig. 15: Front View of the Core and Cavity Blocks

Fig. 16: Top View of the Core and Cavity Blocks

Fig. 17: Right View of the Core and Cavity Blocks

Fig. 18: Isometric View of the Core and Cavity Blocks

The feature tree is shown below: