CHALLENGE REPORT

Week 9 Project 1

Tooling axis:

While working with the part, view the given class A surface from all the 3 given axes. Upon looking the class-A, y-axis was found to be clearing the whole class A.

Create a new geometric set “SURFACE WORK”, under which we will be creating our B and C surface. Create a new geometric set “B SURFACE”.

B Surface

Offset the class A surface and change the colour to any darker shade to recognise the boundary, which are formed due to uneven fillets.

Observe the pattern of omission of the surfaces and create geometric set (s) according to it. In this case, there were missing surfaces mainly in the fillet regions of the speaker compartment and the pocket area.

SPEAKER COMPARTMENT.

While working with the irregularities in the speaker compartment, use multiple extract to extract all the surfaces which are part of the speaker compartment.

In separate multiple extracts, extract all the other surfaces next to other the missing fillet surface and the wall.

Create extrapolate by creating boundary around the missing surface and the bottom part of the walls. Trim them together with the speaker compartment.

POCKET SECTION:

Following the steps which were used to create speaker compartment, create the necessary multiple extracts to extrapolate and trim with each other.

To correct the other surfaces, use the multi-section surface as the surface was not trimmable.

To do this we require 2 profiles and 2 guide curves. To create 2^nd guide curve, we need to create a spline joining the 2 end points tangentially to their resp. surfaces in the direction of the surface propagation.

To create the final B surface, use the boundary and extrapolate to some distance, such that the A and C surfaces intersect each other. To check this, use intersect tool to check the connectivity.

Apply fillets wherever necessary.

C Surface.

To create a class C surface, we need to create a new geometric set “C SURFACE”. Use the sweep command. There are surfaces which are inclined parallel to the tooling axis or is inclined perpendicular to the tooling axis.

Before creating the C surface, we must activate the class A surface. When the edge is parallel to the tooling axis or is inclined towards it, then we should use the sub-option of sweep using draft direction.

We have to carefully select the edge which are actually perpendicular to the tooling axis. Then perform sweep using draft direction by giving the draft direction as the tooling axis.

The remaining surfaces which are either parallel or at any inclined angles are swept using the sub options of reference surface.

The angle given for the draft direction should be 3^o, whereas the angle given while using reference surface should be given as 90^o or 87^odepending on the orientation.

Create a new geometric set “A+C SURFACE” and then join both the class A and class C surfaces together.

The final component:

Create a new geometric set “FINAL COMPONENT”. Trim the A+C SURFACE with the final B SURFACE.

Obtain the draft analysis for the final component and then, go to part workbench and perform closed surface operation.

Creation of Plastic Features:

Locator: It is an engineering feature which is mounted onto the B side of the component. It helps to guide the next component to be fixed at the exact position. Locators are also used to arrest degrees of freedom such that it cannot move or rotate along any axis. Depending on this, there are 2 types of locators:

(i)4-way locator (ii)2-way locator

Heat stake: It is a type of engineering feature which is used in joining process by heating. In this process heat is used to partially melt one part of the heat stake in join with another component.

Heat staking has its own advantages:

• Simple machinery
• Low machinery cost
• Multiple fastening points
• It allows higher density of welds compared to hot air/cold form or ultrasonic welding.

Locator:

First find out the points where locators are to be placed. Create a new geometric set “LOCATORS”. Extract their surfaces. Create points on surfaces.

Create a plane parallel to the point with respect to z-x plane. Create a sketch on that plane and draw 2 perp lines equidistant from that point.

Create a new body and go to the part workbench. Pad the sketch with a thickness of 1.3mm with neutral fiber as the line we created.

Draft the pad for an angle of 0.5^o with all the lateral faces present in the cross shaped pad. Provide a chamfer of 3mm at 45^o and fillet the edges of that chamfer with the same value of chamfer. Fillet all the edges of the locator with a minimum of 0.5mm.

Rename the body as “LOCATOR 1” and pick all the commands form geometric set “LOCATOR” except the sketch, and place it in a new geometric set “LOCATOR 1”.

Create a new geometric set “LOCATOR 2” and extract the surface where the next locator has to be placed. Create a point over it and make sure that the body can be placed in the area properly.

Copy and paste special the body of the locator in the main file. Translate the part using point to point from start point to finish point.

Repeat the 2 above steps with locators 3 and 4.

Note: The locators should be the tallest plastic feature among the other features on the component and must have same height from the surface. Thus, translate along y direction to adjust the height of the feature from the surface.

Heat stake:

The similar way we created the locator, we will be choosing a point from the given set of points and create a plane parallel to z-x plane.

On that we will be creating a sketch with 2 concentric circles, outer radius being 7mm and inner radius of 5mm.

Pad the sketch to a distance shorter than the locator and provide a draft of 0.5^o with respect to its base. Make sure to extend the base below the main component.

Using the same principle of copy pasting the body, place the bodies of the heat stakes on the necessary points on the model.

Now assemble the locators and heat stakes in their respective bodies. Boolean trim them with the main part body. Perform draft analysis of the final component with respect to the tooling axis.

PLEASE FIND THE FOLLOWING FILES:

Part file: CATPart.zip

Report: CHALLENGE REPORT.docx

Images: Screenshots.zip