Week 9 - Challenge 2 - Switch Bezel Design

Aim :- To Create the Switch Bezel 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.

DRAFT: It is the degree of taper that is incorporated into the side wall and cores of the die cast tool to aid in the removal of a part. Primarily, they function to reduce the friction between the part and the tool as it is ejected. Without draft angles, parts can be stripped, dented, or get stuck in the tool.

The Draft Analysis command enables you to detect if the part you drafted will be easily removed. In the case of plastic injection molded parts it also allows the designer to see if there is enough draft on the part to ensure that it can be correctly grained.

TOOLING AXIS CREATION:

Tooling axis is the direction that the mold pulls apart. It is necessary to create a tooling axis to give draft to the component. Tooling axis is created using the Bisecting Method. For the given Class A surface, the best tooling direction for the component is chosen by considering the tooling of the final product. It is chosen in such a way that the component is cleared with minimum tooling.

BISECTING METHOD:

For a given specific direction, it is found that the given component is clearing the tooling in Z direction. On the Class A, a point is created at the geometric centre of the base using the "surface type" in point definition. An axis system is then created with the point as origin.

firstly create a Construction geometic inside this create a Tooling Direction geomatic then Multiple Extract a surface of body where proper view come from a body then create a center point on it .

After create a point on the surface Sketch 1 is create as line on the middle of the surface in point .Considering the Ejection from the cavity of the mould after manufacturing the interior trim (switch bezel) must have the nominal 3-degree draft angle.Hence the tooling direction is created by considering the above factor and bisecting method is used.The base surface of the class – A was extracted and a point at the centre is created and an axis system was inserted to the point with the current feature is disabled.Then, using project intersection along yz plane is created and the two inclined lines were drawn inside the positioned sketch.Then bisecting lines with the two inclined lines were drawn.Now the same procedure is done along the xz plane but on one side we don’t have inclined lines so the centre point is used to extrude a line along the z-direction and gave a measurement of 6 degrees (Tentatively).With these two lines from sketches 1 and 2, the bisecting line is crated and published as Tooling Axis(tooling direction).

CREATION OF CLASS B SURFACE:-

For creating the class-B surface the required surface except the offset surface have been extracted and then untrimmed all the surface.Then all the surfaces have been extrapolated to get intersections between them.Since the thickness of the Switch bezel is 2.5mm the B-Surface was offset to 2.5 mm and the required trim operations must be carried out.

For making a

Class B surface, I will use the following command:

1. Boundary: Select the required boundary if required.
2. Extraction: In this, no boundary is required, so go to extract the flat surface of class A.
3. Untrim: After extrapolating, Untrim those surfaces.
4. Extrapolate: extrapolate those surfaces by as per required .
5. Trim: trim those extrapolate surfaces to get the desired surface.
   
   
   
   To get the radius of fillets the filleted surface is extracted and untrimmed the surface and then the redius is measured.
   Finally, the required corners have been filleted to 12.5mm (15mm-2.5mm)[ 15mm - fillet value of the A-surface, 2.5mm – Thickness of the component ] and 11.5mm (14mm-2.5mm) [ 14mm - fillet value of the A-surface, 2.5mm – Thickness of the component ].

CREATION OF CLASS C SURFACE:-

Class C surface generally connects the Class-B surface to the Class A surface.Referring to the below pic, Class-C Surface is shown.for creating a Class -C surface used the following command:

1. Boundary: pick the boundary for the next operation.
2. Swept: swept the selected boundary with 20mm.
3. Extrapolate: surface can't join properly, so I used to extrapolate those surfaces.
4. Trim: trim those extrapolate surfaces and get a required surface.
5. Join: now join those surfaces with each other and form a single surface.

Now the class – A and Class- C surfaces were joined together by removing the gaps in-between them with the help of extrapolation(tangent continuity) and Trim surface.Then the exact surface of the Switch bezel was trimmed from the above-resulted trim surface with the class-B surface.Then, by defining the part body by using the Closed Surface command in Part Design, the component's solid body is created.

FINAL SOLID MODEL:

After trimming and joining all the three Class A, B and C Surfaces, the final solid model is created in the part body using the Close Surface tool in the Part Design workbench. This is the required solid component - Switch Bezel.

PROCEDURE FOR DRAFT ANALYSIS:-

First the class – A surface is checked before creating the Class –B&C surface and finally the solid body must be analysed. Both can be done by following the below procedures.By changing the view mode to custom view parameters – Material mode then the feature draft analysis is enabled.Then the compass was activated and placed with the tooling axis by dragging the red pointer and then locked it.Then, by selecting the quick analysis mode, the nominal value will be 3 degrees and checked for the component's draft angle.The green colour area shows that it satisfies the 3-degree draft angle. If not satisfied then by using the Running point tool the area is measured and then altered to get a successful draft for the created tooling direction.

DESIGN CONSIDERATION:-

• Class – A surface should be aesthetically smooth and good.
• Class – B surface should have all the supporting features like ribs.
• Parting Line should coincide with the B surface since flashing couldn’t affect the aesthetic of Class – A.
• Class – C surface should also pass the draft analysis.

EXPANDED TREE STRUCTURE:-

PUBLICATION :-

Publication is use to easy accessible of given command and drawing .

CONCLUSION:-

How to form the tooling axis when there are constraints on the number of walls.

To capture the class B and C properly.

To check the feasibility of the component.