Week 8 - Challenge 4 - Coin Holder Design

AIM:

Coin Holder Plastic Component Design Using CATIA V5.

OBJECTIVE:

Creating Center console Coin Holder Plastic Design from given CLASS A and Draft analysis of the component.

Key Points:

• Bisecting method for generating Main Tooling axis
• Generating CLASs B surface from given CLASS A
• Generating CLASS C surface from given CLASS A
• Trimming CLASS B and CLASS c
• Generating Final trim for CLASS A, B, C surfaces
• Generating final plastic component from Surface component
• Generating draft analysis on component
• Conclusion

Tooling Axis (Bisecting Method):

Tooling Axis is an imaginary axis in which direction the tooling operation is performed. In Injection molding, the direction in which the mold is opened closed, is called tooling direction.role in plastic component design, is decided with reference to the main tooling axis of the component. Bisecting method for generating Main

Tooling axis of component.
1. The given Input will be CLASS A Surface of the component, which we need to verify for boundary discontinuities.

2. Then we can make a dummy tooling axis for reference by approximating from part geometry. Observing component from differentdirections, we can assume the dummy tooling axis location. That would also
help as first step of bisecting method.

The Z direction tooling axis, clears the drafts on sidewalls of the component and also top surface of the bezel. It is evident from below image that z direction should be the Tooling axis of the given component.

3. For that we have to create an AXIS System on component to facilitate theExtract a base surface and make a point of surface. Create new axis system on that point. This axis system acts as reference to create dummy and main tooling axis.

4. Now that the tooling direction is defined, we can make temporary tooling axis for the part as shown below. Taking the point as a reference, below image shows temporary tooling axis in Z direction. Taking it as a reference, we can proceed to define actual tooling axis using bisecting method.

5. By looking at the component and desired bisecting approach, we can assure that the Main Tooling axis is in the same direction as of dummy axis. Moreover, upon looking for symmetry of the component, we defined the Main tooling axis as in the same line of previous axis. It is as shown below.

GENERATING CLASS B SURFACE FROM THE A SURFACE INPUT:

THE critical parameter to consider is the component thickness. CLASS B is surface offset equal to part thickness. Given CLASS A is divided into four main surfaces which will be helpful in
generating CLASS B surface. Below image shows the CLASS A, and methodology to follow in next steps.

offsetting Bin Walls:

Avoiding fillets given here, Walls in violet colour can be divided into 4 surfaces. Each surface is extracted from CLASS A, Untrimmed and extrapolated to get the desired output. It will form the base for
final CLASS B surface. Extracting the surface highlighted in green, using "Extract" command.

offset the base:

Similarly, we can extract wall base surface, untrimmed and extrapolate it. And offset it by 2.5 mm.

offset Outer Flanges:

Here we have a Complex outer flange surfaces which we need to extract and offset separately. Here is the first offset of outer flange. Here is the second offset of the flange. It is extracted, untrimmed, and joined together to get one surface and then it is offset to 2.5 mm value. Below shows both surfaces output.

Generating CLASSc surface from CLASS A surface:

CLASS A surface is used as reference to generate CLASS C surface. We need to extract outer boundary from CLASS A surface. Extract boundary using "Multiple Extract" Command. Here we can use tangent continuity option to select appropriate edges. We have to use this command several times to extract all edge.

Extracted boundary is used to generate CLASS C surface using "Sweep"N command. This surface is sweep along main tooling axis to generate draft angle along tooling direction. We need to be
careful while generating draft angle wrt tooling axis. In our case, we need the CLASS C sweep along 90° angle wrt the class A surface to generate closed surface. This outputs our final CLASS C

Trimming cLASS B and CLASS c:

Below image shows CLASS B and CLASsS C surfaces ready to trim with respect to each other. Trim CLASS B and CLASS C surfaces

Generating final plastic component from Surface component:

Above method has given a closed surface component as output. But, for manufacturing purpose, we need too have a solid body part. For that we need to migrate to CATIA V5 part workbench. Here, in part workbench, we need to insert new body, insert menu "Body" command. This creates a new body inside part module. In body, we can use "Close Surface" command to convert our closed surface component to Solid body part. As the name suggests, all surfaces should be closed to get proper solid body. Choose the command and select our surface component. It will be converted to Solid body component. One of the main points is that, it won't convert surface part to solid body if any of the boundary is open from surface component. And the final output solid part will be as shown in image.

Generating draft analysis on component:

Draft analysis gives you the overall information about draft angles required with reference to main tooling axis of the component. While designing, we could give the draft angles to desired faces to clear the tooling direction. To evaluate given draft angles, we use draft analysis tool in CATIA V5.

Draft analysis steps.

1. Material mode plays a vital role in generating draft analysis. The tool calculates draft angles required based upon material properties and behaviour during tooling operation. Not setting up, will give you a warning message.

2. After setting material mode, click on "Feature Draft analysis" from Insert menu. A dialogue box will be opened.