Week 8 - Challenge 1 - Base Bracket Design

Base Bracket Design

AIM:

Create the Base Bracket Plastic component through the given Class-A surface. To begin with, the tooling axis for the given Class A Surface should be created meeting the requirements of the draft angle and at the end perform the Draft analysis on the model.

CAD DATA:

The CAD DATA is been given as CATPART, STEP FILE, IGES PART.

INTRODUCTION:

• CLASS-A SURFACE:

A surface made by the designer which is given as an input to the plastic modeler to work on. It is aesthetic surface and the outer most surface.

• CLASS-B SURFACE:

A surface below a certain thickness from the class-A surface is class-B surface. This is the surface that contains engineering aspects of a model.

• CLASS-C SURFACE:

A surface that joins class-A and class-B surfaces is class-C surface.

METHODOLOGY:

In this model we have focused on the following things:

1. Tooling axis
2. Draft analysis
3. Class-B surface
4. Class-C surface
5. Making a solid model from surface.

Following tools were used to reach the final step:

1. Extract
2. Un-trim
3. Trim
4. Extrapolate
5. Offset
6. Edge fillet
7. Boundary
8. Sweep
9. Join
10. Close (part design)

Procedure :

Given Class A Surface :

STEP 1:

Check the connectivity of the Class A Surface
Ensure that there is no gap between the component, using join command.
We can visually check it or by clicking boundary command.
It has 3 boundaries one outer and two inner circle boundaries.
Therefore first check completed.

STEP 2:

Find the tooling axis of the component. The tooling axis is nothing but the mould opens or cavity opens.
Check visaully which is the best possible tooling axis.
Check all three axis.
Along x it possible but expensive and y is not possible.
z is the best possible tooling axis.

Tree Structure of Tooling Axis :

Creating a Tooling axis along Z:

Therefore the main tooling axis is along z axis.
Now perform the Draft analysis using the Featured Draft Analysis tool in the tools.
Then after opening the draft analysis tool box go for the compass and place the compass alinged to tooling axis and click on the lock symbol after alinging and further click on the surface.

FOR DRAFT ANALYSIS:

1. Go to insert< analysis< feature draft analysis.
2. Align the tooling axis with the compass.
3. Click on the surface and see that the surface is within the permissible limit of the draft values.
4. The surface should be green and in the column proper value (3deg) should be inserted.

Now creating Class B Surface:

• Intially extracting the right side rib using extract option from Class A surface.
• Then perform Extrapolate inorder to increase the length
• Now trim the surfaces to required surfaces
• Then Offset the surface inorder to get the required thickness
• Similary create the left side rib
• Now Similarly get the slanted as well as the flat surface and offset it to desired value
• And now trim inorder to get the required surface
• Now fillet the surface to required amount.

Procedure :

1. Extract the flat surface.
2. Un-trim the surface.
3. Extrapolate it.
4. Offset it by 2.5mm i.e. thickness.
5. Extract the slant surface.
6. Un-trim the surface.
7. Extrapolate it.
8. Offset it by 2.5mm i.e. thickness.

Tree Structrure of B Surface :

B Surface :

Now Creating Class C Surface :

EXPLANATION ON BISECTING METHOD:

Bisecting method is basically use to find the proper tooling axis using the dummy tooling axis. In Bisecting method, bisecting line is used which either bisect the two line or it will show error which means the two lines are parallel to each other. In order to know whether the particular surface is toolable or not we intersect the surface with the respective plane and get a sketch which consist of two lines and with the help of bisecting line option we bisect the line which creates a line at the mid point of the two lines. Like wise we create tooling clearing axis for x and y which will be used to create the main tooling axis using the bisecting line option in in the line comand.

Procedure :

• Extract the boundary of the class-A surface.
• Extract the boundary of the holes on the class-A surface.
• Use sweep command on the boundaries one by one to get the class-C surface.

Tree Structure of C Surface :

Join the class-A and class-C surfaces together.

Here Class A Surface, Class B Surface and Class C Surface combine together and Whenever trims this surfaces We found Bace Bracket Close Surface.

Draft Analysis of Close Body :

Full Tree Structure :

All Views of Bace Bracket :

Conclusion :

The Base Bracket Plastic component through the given Class-A surface is created by using instructions and data given in the above question in the CATIA V5 software.