Week 8 - Challenge 1 - Base Bracket Design

:

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

PROCEDURE :

• Creation of Tooling Axis.
• Creation of Class B and Class C surface.
• Creating a solid part out of surface molding.
• Draft Analysis of Class A surface and final plastic component.

TOOL USED:

CATIA V5.

INTRODUCTION:

In this project we are designing a base bracket using given class A surface. The approach includes creation of Class B surface keeping 3 mm thickness in mind for the complete component. The design also included Class C creation from the given parent surface.

MATERIAL USED:

Polyester:

It is a category of Polymers that contain the ester functional group in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethelene terephthalate (PET). Polyesters include naturally occurring chemicals, such as in plants and insects, as well as synthetics such as polybutyrate. Natural polyesters and a few synthetic ones are biodegradable, but most synthetic polyesters are not. Synthetic polyesters are used extensively in clothing.

Polyester fibers are sometimes spun together with natural fibers to produce a cloth with blended properties. Cotton-polyester blends can be strong, wrinkle- and tear-resistant, and reduce shrinking. Synthetic fibres using polyester have high water, wind and environmental resistance compared to plant-derived fibers. They are less fire-resistance and can melt when ignited.

Liquid crystalline polyesters are among the first industrially used liquid crystal polymers. They are used for their mechanical properties and heat-resistance. These traits are also important in their application as an abradable seal in jet engines.

USES:

Fabric wovens or knitted from polyester thread or yarn are used extensively in apparel and home furnishings, from shirts and pants to jackets and hats, bed sheets, blankets, upholstered furniture and computer mouse mats. Industrial polyester fibers, yarns and ropes are used in car tire reinforcements, fabrics for conveyor belts, safety belts, coated fabrics and plastic reinforcements with high-energy absorption. Polyester fiber is used as cushioning and insulating material in pillows, comforters and upholstery padding. Polyester fabrics are highly stain-resistant since polyester is a hydrophobic material, making it hard to absorb liquids. The only class of dyes which can be used to alter the color of polyester fabric are what are known as disperse dyes.

Polyesters are also used to make bottles, films, tarpoulin, sails (Dacron), canoes, liquid crystal displays, holograms, filters, dielectic film for capasitors, film insulations for wire and insulating tapes. Polyesters are widely used as a finish on high-quality wood products such as guitars, pianos, and vehicle/yacht interiors. Thixotropic properties of spray-applicable polyesters make them ideal for use on open-grain timbers, as they can quickly fill wood grain, with a high-build film thickness per coat. It can be used for fashionable dresses, but it is most admired for its ability to resist wrinkling and shrinking while washing the product. Its toughness makes it a frequent choice for children's wear. Polyester is often blended with other fibres like cotton to get the best of both worlds. Cured polyesters can be sanded and polished to a high-gloss, durable finish.

CLASS A:

Following surface is given as the input for the component creation.

To continue with the design process first we need to find out the tooling axis for the surface and check for all the drafts using Draft Analysis tool of CATIA.

TOOLING AXIS:

The direction of core and cavity is known as TOOLING AXIS.

DRAFT ANLYSIS:

DRAFT ANALYSIS refers to a tool that allows users to determine if they can remove the part they are designing from the tool being used to design it.

Draft Analysis for Surface A:

The analysis is done for 3degree draft. So as can be seen all the surfaces are more than 3deg.

Class B:

• Now for Class B creation, we have extracted surface from Class A and untrimmed them to obtain the original parent surface.
• These surfaces are then offset to the required thickness.
• After offsetting, all the surfaces are trimmed into the required shape.
• Required fillets are given to the surfaces.

Class C:

• For creating this surface we have extracted the boundry of Class A using multi-extract and then converted to smooth curve.
• Now this smooth curve is swept along the draft direction with a 3deg draft.

Final Trims:

Class A + Class C:

To make sure that there is not any open boundry between class A and class C, we have used join option to created the single body. This is done to make sure that the parting line doesn't lie between the these two surfaces.

Class A + Class B + Class C:

For this we have trimmed the above shown surface with the Class B surface using trim feature.

Draft Analysis on the Final Component:

For this analysis, main tooling axis is taken draft reference.

Following results were obtained:

CONCLUSION:

Create the Surface CATpart from the below 2D drawings. The part models should be a replica of the 2D drawings provided. Geometry should be created using the Thicken command.