Project 1 - Door Trim Lower with Engineering Features

1. Aim

To Create an Solid Component along with some Engineering Feature's such as Heat Stakes, Locators, Ribs and Dog House from the given Class A surface. Also the Engineering or B side Features should be designed as per the Design Standards.

2. Engineerig Features

2.1 Heat Stakes

Any Component that is designed should be assembled or attached eachother to obtain the final product. Heat Staking is one of an efficient method for the thermoplastic materials where the children part would have an long thermoplastic stud which is inserted into the parent part and the stud will be heated to melting point and then cooled. with this both the parent and Children part will be attached together.

2.2 4 Way or 2 Way Locators

Locators are mostly used to locate the workpiece to the workhold device or the working position. Also 4 way Locators are used to arrest the degrees of freedom of and component along translational movement along 2 plane x and y axis.

2.3 Ribs

For an Plastic component, the ideal Thickness would be 3mm with a deaviation of +-30%. Here, Ribs are used to increase the Stiffness and Strength of an moulded part without increasing any overall thickness. It is also used for

• Locating and Arresting components of an assembly.
• Providing alignment in mating parts.
• Acting as stops or guides for mechanisms.

2.4 Dog House

When a Plastic Component has more than a 3mm of thickness, then it has an possibility of creating an Sink mark in the Class A Surface which can spoils the component's aesthetic look. In these regions Dog House can be helpful at the same time it can act as an supporting feature too. It has certain design rules to be followed while designing like,

• It should have a minimum height of 12mm
• Dog house wall thickness at intersection of part wall should be 40% or less than main wall thickness

3. Procedure

3.1 Work Flow Pattern

• Creation of Tooling Axis
• Creation of B Surface
• Creation of C Surface
• Creation of Dog House
• Assembling
• Draft Analysis

3.2 Creation of Tooling Axis

For the Creation of Tooling axis, Normal to surface method was used. Because of so many surfaces, it is not possible to create line to each of them for bisecting.

While Performing the draft analysis, Class A Surface clears at 3 degree of draft.

3.3 Creation of Class B Surface

The thickness of the component is not mentioned, So it is taken to be 2.5mm. With this the class A surface was offseted to 2.5 mm to create class B surface. While offseting, some of the small fillets and got convexity error and it was not offseted. To create the unoffseted surfaces, it was segregated into sections to perform the trimming operations. Each sections were Extracted--> Extrapolated and then trimmed. For fillet radius, it was taken reference from the Class A Surface.

Offseted Class B Surface:

Segregated Class B Surface:

Final Class B Surface:

3.4 Creation of Class C Surface

Class C Surface is nothing but the surface which joins Class A and B. For the Creation of Class C Surface

• The surface which are perpendicular to the tooling axis will be Sweeped along reference to surface method at 90 degree angle.
• The surface which are parallel to the tooling axis will be Sweeped along draft direction method at 3 degree angle.

After the Creation of Class C, Class A and C surface was joined and trimmed along the Class B Surface to create the final Closed surface.

Then in part workbench it was converted into Part by using Close Surface Tool.

Class A and C Surface:

Final Close Surface:

3.5 Creation of Engineering Features

For the creation of all Engineering Features, a flat B side surface was extracted to create a plane and to draw an Positioned Sketch. With the created plane, Skectches were drawn --> extruded --> Thickened . Dog House Has an Shell like shape, it can't be manufactured only with Main Tooling Axis, so for that there will be an additional Tooling Axis namely Sidecore Tooling Axis.

3.5.1 Locators

For the Locators,

• Draft Degree - 0.5
• Fillet Radius - 0.25mm
• Thickness at Tip - 0.75mm

Sketch:

4 Way Locator design:

3.5.2 Heat Stakes

For Heat Stakes,

• Height - 20mm
• Draft Degree - 0.5 degree
• Fillet Radius - 0.25mm
• Inner Diameter - 5mm
• Outer Diameter -7mm

Sketch:

Design:

3.5.3 Ribs

For Ribs,

• Draft Degree - 0.5
• Fillet Radius - 0.25mm
• Thickness at Tip - 0.75mm

Sketch:

Design:

3.5.4 Dog House

For Dog House,

• Wall Thickness - 2mm
• Core Wall Thickness -1mm
• Outer Wall Fillet Radius - 3mm
• Inner Wall Fillet Radius -1mm
• Core Wall Fillet Radius - 0.25mm
• Main Tooling Axis Draft Degree - 1.49 degree
• Side Core Tooling Axis Draft Degree - 0.49 degree

Sketch:

Design:

3.6 Assembling

After the Thickening method all the parts were assembled into the Main Part by using Boolean Operations.

Final Part:

3.7 Draft Analysis

3.7.1 Draft Analysis on Final Part

On the Final part, draft analysis was performed at 2.9 degree.

3.7.2 Draft Analysis on Engineering Features

Draft Analysis of Heat Stakes at 0.49 Degree:

Draft Analysis of Locators at 0.49 Degree:

Draft Analysis of Ribs at 0.49 Degree:

Draft Analysis of Dog House from Main Tooling Axis at 1.49 Degree:

Draft Analysis from Side Core Tooling Axis for 0.49 Degree:

All B side features at 0.49 Degree:

4. Conclusion

With the given Class A surface as an input, Tooling Axis, Class B Surface , Class C Surface and all the Engineering Features were Created. Also both the Final Component and Engineering Features were clearing the Draft Analysis.