Week 8 - Challenge 6 - Core & Cavity Design

                                                 SWITCH BEZEL CORE & CAVITY DESIGN

Objective:

  Create the Core and cavity blocks for the switch bezel designed in the earlier challenge.

 Given Class A Surface:

    Class A surface is the outer most surface of the component, it is an aesthetic surface. It is also called as Strak. As a designer we don't have rights to  modify the class A surface without permission.Then we have check the class A surface whether it is joined or not by using boundry command if the boundry command shows only the the outer edges means we can work on class b otherwise we have to correct class A then only we can work on Class B.

 Tooling Axis Creation:

   Tooling axis is very important to design a product. It is nothing but the direction of the molds open close and whether it is moves in the x, y or z direction. First we have to decide which direction is probabily suitable for the particular product. Once we get the Cass A Surface, we can check the surface and able to create the tooling direction.

Procedure to Create the Tooling Axis:

• First, we have to create a point on the flate face or circle midpoint to create a line.
• Once we created the point means we can create a line (Dummy axis) on the point in the suitable direction. We can find the suitable direction by simply see the object from x,y and z directions. If the object is fully visible from one of the direction means that is the line direction.
• After finding the direction just create a dummy axis and axis system.
• Then intersect the part with yz plane and create an bisecting line using the side angular lines which might create a problem.
• Do the same steps in the xy plane to create an another line.
• After creating the two line which might create a problem, then draw a biseting line using the two bisecting line that we drawn from the yz and xy plane.Here we used Bisecting Method to create the Tooloing axis.

Draft Analysis Report:

Draft: Draft is used to remove the component fom the core and cavity. It will reduce the wear in component and molds so the the life of core and cavity will increase.

Draft Analysis: The Draft Analysis allows the user to easily analyze a part for proper draft angle. A Draft Angle describes the amount of taper for molded or cast parts perpendicular to the parting line.

The minimum draft angle ranges between 0.5 o 3 degree. Mostly 3 degree angle is widly used to make many components.

Class A Surface Draft Analysis:

Procedure to do Draft Analysis:

• Once we created the tooling axis means we can do draft analysis. First we have to switch the view mode to shading with material.
• After switching to shading with material mode we can now click draft analysis tool. Then we have to place the compass on the tooling axis by clicking and draging  the compass red dot.
• After placing the compass lock the direction and click the surface to do draft analysis.

•  Here we can see the draft analysis of Class A Surface. The green color indicates that the draft angle is more than 3 degree so we can take this for further process.

Final Plastic Component:

After the creation of class B and class C surface the final surface is created, then the final surface converted to solid model by using closed surface command in part workbench.

Parting surface:

    Designed for the removal of the plastic product and the cold slug, the parting surface is where the core meets the cavity, and usually locates at the largest section of a product.

Considerations While designing parting surface

• The parting surface should be located at the largest section a plastic part.
• The selection of the parting surface should be helpful for mold release / product ejection.
• The parting surface should be selected to meet the appearance requirements of the plastic product.
• The selection of the parting surface should ensure the precision requirements of the plastic product.
• The selection of the parting surface should facilitate mold making.
• The selection of the parting surface should be helpful for mold venting.

Here the class B surface is the parting surface area.

Parting Line:

 A parting line, in industrial casting of molds, is the border line in which draft angles change direction. One can check the parting line in the mould or product which divides the two half, that the core and the cavity of a molded part. It is sometimes a starting point for the mold parting surface.

Here the parting line is the intersetion between the class B surface and Parting surface.

 Core & Cavity:

   The core & cavity are the shaped sections in either half of the mould tool which give the plastic product its final shape. The hot molten material is injected into the core & cavity and then sets hard into shape. The design of the core & cavity is essential in the correct formation of the product.

Core:

 The core (B Side) is usually the interior or noncosmetic side of the part. The core side also contains the ejection mechanism that pushes the completed part out of the mold.

Cavity:

 The cavity (A Side) is the void inside the mold that the molten plastic fills. A mold is a hollow form typically made from stainless steel that has plastic injected into it to manufacture a plastic part.

Publications:

It is used to easily find out the main parts like tooling axis, class A,B and C surfaces.

Core and cavity blocks in various orientations (Isometric, Front, Side, and Top View):