Week 9 - Attachment Feature Creation (Ribs & Screw Boss) - Challenge 1

DESIGN METHODOLOGY

TITLE: Attachment Feature Creation (Ribs & Screw Boss) - CATIA V5

Objective: To create the ribs and srew component through the given Class-A surface. As well as, creating the tooling axis for the given Class-A Surface which is meeting the requirements of the draft angle and at the end perform the Draft analysis on the model.

Specifications:

Switch Bezel Thickness = 2.5mm

Minimum Draft Angle = 3 Degrees

Definitions:

Class-A Surface: it is a surface created by the styling team which is then given as an input to the plastic designer to create the plastic component. It is the aesthetic surface and the outer most surface.Class 'A' surfaces are primarily used in the automotive environment and refer to those surfaces which are visible in a product.

Class-B Surface: it is the surface below a certain thickness from the Class-A surface The Class B finish is a quality finish with only minimal imperfections.

A Class B finish is the most common finish for exterior surfaces. It is normally specified on surfaces such as external covers, panels, and parts that are fairly prominent created by the plastic designer. This surface contains all the engineering aspects of a model.

Class-C Surface: it is the surface which joins the Class-A and Class-B surfaces together.

Draft: it is the amount of taper or slope given to cores or other parts of the die cavity to permit easy ejection of the casting from the die casting die.

Ribs- create the rib handle for strength

Screw boss-

General Guidelines for Bosses:

• Draft - 0.5 degrees on the walls of boss
• Thickness - Typically 40%* of the nominal wall at the base.
• Height to Diameter Ratio - 3:1
• Radii - 0.25mm maximum radii.

Class A surface

Class-B: we create the Class-B surface by extruding the Class-A surface by 2.5 mm

1. First, we will use the Extract, Un-trim, Extrapolate, Trim and Offset commands on the base surface, the walls and the Bezel rest surface of the Class-A surface separately to create the desired Class-B surface.
2. After that, we will use the Trim command to get our proper desired Class-B surface.
3. We will give proper fillets to the edges of the Class-B surface

Class b surface

Class-C: we create the Class-C surface by extruding the edge boundaries of the Class-A surface by 2.5 mm.

1. First, we extract the outer edge boundary and inner edge boundary of the Class-A surface separately.
2. Then, we sweep each of these boundaries using the sweep command. We select the Line option on the sweep command menu, the extracted boundaries as Guide curve 1 and the tooling axis as the draft direction. Also, we specify the draft angle as 3 degrees.
3. After that, we join all the Class-C surfaces with the Class-A surface by using the Join command.
4. Lastly, we use the trim command to join the Class A, B and C surfaces together and obtain the proper desired surfa Class-C Surface

Class C surfcae

Ribs and screw boss creation