Challenge

Week 8 - Challenge 2 - Switch Bezel Design

AIM

To create a Switch Bezel Plastic Component through a given Class A Surface and perform Draft Analysis on the final plastic component.

OBJECTIVE

CLASS A SURFACE

Class ‘A’ surfaces are primarily used in the automotive environment and refer to those surfaces which are visible in a product. In other words: A - class surfaces are those aesthetic/free-form surfaces, which are visible to us (interior/exterior), and have an optimal aesthetic shape and high surface quality.
The surfaces or regions which are visible nowadays are considered for Class-A modelling. It is one of the reasons why the importance of Class-A modelling is increasing day by day. Majority of the time this term is used in Plastic Part designs.

CLASS B SURFACE

The Class B surface is created from the Class A surface, keeping the thickness of the component in check.
The Class B surface resembles an offsetted surface from the Class A.

CLASS C SURFACE

The Class C surface is used to bind the Class A and Class B surface together in order to form a closed surface.

PROCEDURE

Creating Tool Axis

Initially the given Class-A surface was imported and checked for any discrepancies in the boundary and performed draft analysis on it at 3-degree draft.
The ejection from the mould after manufacturing the interior trim must have the nominal 3-degree draft angle.
Hence the tooling directions created by considering the above factor and bisecting method is used.
The base surface of the class-A was extracted to create a reference point on the surface using the point, create a line in the z-direction and an axis system was inserted to the point.
Then using projection intersection along the yz-plane is created and the two inclined lines were drawn inside the positioned sketch.
Then bisecting lines with the two inclined lines were created.

Now the same procedure is done along the xz-plane but on xz plane, we only have one surface line so the centre point is used to extrude a line along the z-direction and gave a measurement of 6 degrees from the surface line.

Bisecting these two lines sketch1 and sketch2 the bisecting line is created and published as a tooling axis.

Creating Class B surface

Initially the class A surface is divided into 3 sections- Bezel rest surface, walls, base.
Then all the surfaces have been extracted, untrimmed and extrapolated one by one to get intersections between them.

Since the thickness of the Switch bezel is 2.5mm, all the surfaces were offset to 2.5 mm.

once all the surfaces are created (i.e., bezel rest surface, walls, and base surface). The required trim operations were performed to form a class-B surface.

To Perform the fillet operation. Fillet value should be calculated from the Class A surfaces for every edge in the B surface.
Finally filleting the edges of class B surface considering thickness value to it.

The fillet value should be calculated to ensure the component has a uniform thickness.

Creating Class C surface

The required outer edges of the A-Surface were extracted using Multiple Extract. Then for avoiding the patches the curve is smoothened using the Curve Smooth option.
Sweep operation is performed (with draft direction) selecting the smooth curves as the guide curve and tooling axis as the direction and draft angle as 3-degree.

Then by using extrapolate command the edges were intersected between the surface corners which eases the trimming operation.

Join class-A and class-C surfaces. Make sure that there is no unnecessary boundary present, if there, then increase the merging distance (not more than 0.003mm) and even after there is some unwanted boundary, extrapolate class-A by a small distance and trim it with class-c instead of joining them.

Creating Solid Body

Later, CLASS C and CLASS B surfaces were trimmed and forms the switch bezel surface.

Using the surface created, the solid component was obtained using the Close surface feature present in the part workbench.

DRAFT ANALYSIS

First, we should change model into material mode.
Go to insert and in analysis select feature draft analysis.
Align the compass along tooling axis and lock it.
Next click on the surface and see that the surface is within the permissible limit of the values.
The green colour area shows that it satisfies the 3-degree draft angle. If not satisfied then by using the Running point tool the area is measured and then altered to get a successful draft for the created tooling direction.

On given Class A surface

On obtained PART BODY

EXPANDED TREE STRUCUTRE

CONCLUSION

The creation of Tooling axis and Draft analysis were performed.
The solid component was created from the surface geometry.
The necessary screenshots and files were attached.
The Class A, B, & C surfaces and also the Tooling Direction have been Published.

Ship work like this
in your own course.