Week 8 - Challenge 3 - Coin Holder Design

REPORT FOR COIN HOLDER DESIGN:

Aim : To create the Coin Holder Plastic component through the given Class-A surface.

• To create the tooling axis for the given Class-A Surface meeting the requirements of the draft angle and at the end perform the Draft analysis on the model.

Creation of Tooling Axis:

The tooling axis is the direction of drawing a sheet metal where the finished component is easily ejected on a particular direction and axis. In Molding, machine arrangement is given to open the mould along a direction which is known as Tooling Direction. In other words. The mould is built from two separate halves (Core and Cavity) and tooling direction basically defines the direction of mould pulls apart.

In the given model we are using the Normal To Surface method.

For creation of tooling axis, a point is inserted on one of the surface of class A surface through which tooling axis can be drawn in Y direction.

Class A surface with point on the surface:

Material Selection

The material can be used for manufacturing Coin Holder is Acrylonitrile Butadiene Styrene (ABS). Because of its some features such as:

• The styrene provides the copolymer with a shiny, tough exterior.
• Provides quality surfaces and good resistance to chemical agents.
• A wide variety of adjustments can be made to enhance impact resistance, durability and heat resistance.

For manufacturing the coin holder injection molding method can be adopted. It would be the right manufacturing method. Because it is a right way to create the exact moulding for the required product. This is a common method is used to produce a high volume of plastic parts like car parts etc. Products can also be made with increased flexibility to suit the needs of designers or engineers.

Class A,B & C Surface

Class A Surface:

It is the outermost aesthetic surface which is visible to customers (the outermost visible surface of a product).

Here, class A surface is given:

The class A surface is joined inorder to make it a single part and then checked the boundary to confirm that it is closed.

Class B Surface:

It is the offset of the class A surface at a particular distance. The offset distance depends on the thickness between Class A and Class B surface.

Here, the thickness given = 2.5mm.

Procedures to build class B surface:

• Extracted each and every flat surfaces from class A.
• Then multiple extract is used to extract the curved surface along with flat surface.
• Untrimmed all the extracted surfaces and offseted those surfaces 2.5mm downwards.
• Extrapolated the offseted surfaces inorder to make sure all the surfaces are in contact.
• Trimmed the offsets to get an output same as class A surface
• Fillets are given to the required edges based on the thickness and curvature of the class A fillets.

Class C Surface:

This surface connects the Class A and Class B surfaces. (Surface in between Class A & B surfaces)

Procedure to build Class C surface:

• Boundary of class A surface is extracted and then smoothcurved the boundaries
• Then that boundary is swept perpendicular to the Class A Surface until it gets coincided with the offseted class B surface.

Joined and Closed Class A,B & C surface:

After creating class B & C surfaces joining operation is done between class A and class C surfaces. Then, Class B surface is trimmed with joined Class A & C surfaces to get a whole closed single surface. Then in part workbench using closed body command, a solid body is generated.

Closed surface:

Solid Body:

Draft Analysis:

In the criteria of making a plastic material, the mold should release the material when finished. if the mold surfaces are 90 degrees the material won't release from the mold because of friction due to contraction of material when cooled.The ejection of the part from mold depends on the draft. A zero draft can result in difficult or no ejection. It is recommended to add a draft of 3 degree or above inorder to remove it from the mold without any damage.

Procedure:

• Change the view mode to customize view parameters and give material as view mode.
• In the draft analysis toolbar, set the draft values and color (3 degree and above - green, 0 to 3 degree - blue, less than 0 - red).
• Drag and drop the axis system on the tooling axis and lock it.
• Perform draft analysis.

Draft analysis of Class A surface:

It is clearly shows the above figure with marked area is having blue colour. Thus the marked area is with draft angle less than 3 degree. Hence to eliminate this the Class A Surface is to be modified.

Draft analysis of final plastic component:

Screenshots of the solid model with the proper color code of the draft angle in various orientations:

Tree Structure: