Week 8 - Challenge 2 - Switch Bezel Design

AIM

Designing a Switch bezel:

Objectives:

a) To create Class-B and Class-C surface from given A-surface of a switch bezel and create a solid body.

b) To perform draft analysis on Class-A surface and complete body.

For creating surfaces and performing draft analysis we need a tooling axis. Here it is done by bisecting and sketch method.

Tooling axis:

A uniform surface is created by combining all patches using 'Join' command. A point is marked at the centre of the plane in the depression of the Class-A surface. An axis system is then set with the point as the origin. The Z-X plane and Z-Y are intersected with the body to form the curves of intersections. Tooling in Y-direction is created with by bisecting method using the bisecting command option under line command. Tooling in X-direction is created by inclining a line 6 degrees from the intersection line.

Final tooling axis is created by bisecting the toolings in X and Y directions.

Procedure for creating Tooling Axis

1. A Reference Point is created along the Surface zero and new Axis system is created
2. The X Direction along the Class A and Y direction along the Class A were used to create Tooling direction
3. Finally the Tooling axis is created by bisecting the two lines and it is published. Class A Surface as input using surface operation commands Class B is developed
4. The tooling Axis determines the direction of Class C boundary swept with draft direction.
5. When viewing from tooling direction normal all the parts that are drafted should be visible so it gives a rough idea to determine product manufacturing in Injection molding.

Tooling in Y:

Procedure for B Surface Creation

1. The next step is to design B surface for the input which is usually the surface where all engineering aspects and support creations are done.
2. The B surface Creation is performed using surface operations in CATIA which is an offset from Class A with dimension proportional to the thickness of the part
3. In Switch bezel the B surface is offset 2.5mm from the input which is the thickness of the part
4. The B surface is an extrapolated surface compared to A surface and forms the bottom skin of the part.

Procedure for C Surface Creation

• The Next step is to from the C surface which is an intermediate surface between A and B and is used to give the closed surface appearance to the design
• The C Surface is swept using the profile as boundary line of Class A which is the Guide curve with a subtype along draft direction.
• The Direction of the sweep is the tooling direction formed earlier
• The draft angle for the sweep operation is provided which is 3 Degree and surface is swept for length above the thickness of the specified part
• The C surface is refined using smooth Curve options to remove the complexity and patches along the swept surface
• Finally the Class A and Class C surfaces are joined together and convexity of surfaces should be less than 0.003mm and the surfaces are merged.

DRAFT ANALYSIS:

Procedure for Draft Analysis Procedure

• The part created has to be changed to material mode in display frame
• Then by enabling compass definition the axis system is pan along the direction of the part and aligned in line with the tooling direction
• Lock Direction is applied that fixes the compass and then the mode dialog box is formed by snapping at any point on the part
• The Colour Codes are classified and Draft Angle are applied
• Then the Running point analysis is used to hover around the part to analyse the permissible draft angles and the analysis is saved

VIEWS OF THE PRODUCT:

ISO METRIC VIEW

FRONT VIEW

TOP VIEW

SIDE VIEW

CLOSED SURFACE:

GEOMETRICAL TREE: