Week 8 - Challenge 4 - Coin Holder Design

• AIM/OBJECTIVE: To create Coin Holder design

• DETAILED REPORT:
• Terms utilized:

1. Class A surface: It is the vehicle's external surface that provides it an appealing appearance. It can be physically touched. Reverse engineering is used to extract it from clay modeling. This surface is provided to the plastic product designer as input. Computer-aided industrial design programs are used to create Class-A surfaces.
2. Class B surface: The offset from class A surface is used to produce the class B surface. All engineering features such as screw Bosses, Dog house, ribs, and mountings are produced on this surface.
3. Class C surface: The surface that connects class A and class B is known as Class C surface.
4. Tooling Axis: It is the direction in which core and cavity opens and closes.
5. Slider direction: The mold release direction of a particular part may not be compatible with the mold opening direction of the Injection molding machine (product undercut) due to special design specifications. The slider, also known as slide, is a mold mechanism that was developed to tackle the undercut issue. The primary objective is to convert vertical mold opening and closing movement into horizontal movement. Different structural forms have been created to deal with the scenario when the undercut is placed in the core or cavity.

• METHOD FOLLOWED:

1. Checking continuity of class-A surface.
2. Deciding an appropriate tooling direction and creating a tooling axis.
3. Performing draft analysis on class-A surface.
4. Creating the class-B surface from the given class-A surface.
5. Creating the class-C surface to join class-A and B surfaces.
6. Creating the solid body by using the closed surface feature.
7. Performing the draft analysis on the final Plastic component

1) Checking continuity of class A surface:

We must check the continuity of a given class-A surface to guarantee that it is properly joined or does not include any discontinuities.We can do this by using join or boundary commands.We can see that the surface has a continuously linked boundary, which is shown by the green line.

We can also check this by extracting boundry as shown in below image

2) Creating main Tooling axis

1. To begin, extract the basic surface and create a point on it. Insert the Axis system at that point. Take the intersection of the class A surface with the axis system's XZ plane.
2. Draw a line normal to the surface at that point.

(If no draft is there for component, You have to just create axis acc. To that , or ask engineer who create class A surface to give some draft. You are not authorized to modify it.)

4) Creating class B surface from class A surface

Split the component into different patches. Give different colours to different patches.

Follow the same procedure for all surfaces except for connecting fillet surface.

• Extract the class-A surface
• Untrim the surface
• Extrapolate untrimmed surface
• Offset it by 2.5 mm distance
• Trim unwanted extra surface
• Applying fillet as per formula to obtain uniform wall thicknes

By following procedure class B surface is created as follows:

5) Creating class-C surface to join Class A and B surfaces.

• To obtain a class-C surface follow the below methodology.
• First sweep extracted curve at 90 degrees to reference surface. This is a part of the class C surface.
• Sweep curve in draft direction and create surfaces as shown.

• Creating Hole:

Extract Boundry surface. Extract surface around the hole. Sweep outside then trim it with C surface.

• Trim class C with class B surface to get a closed component.

6) Creating solid model by using closed body feature:

• A solid model is created from a closed surface in the part workbench by using the closed surface command.