Week 8 - Challenge 1 - Base Bracket Design

TOOLING AXIS:-

• 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).

DRAFT ANALYSIS:

    Draft analysis is performed on the components where the ejection of materials happens after the material is made inside the tools. In the case of manufacturing, the blank sheet after turning into automotive panels like Hood, Fender, Roof, Side Doors, Back Doors etc. need to be removed from Panel Dies. If a considerable amount of draft angle is not provided, the removal of components from the tool will be difficult. It’s the same in the case of mold(plastic component) after getting filled inside the core and cavity, it needs to get ejected easily with the help of ejectors.

 CLASS A SURFACE:

Class ‘A’ surfaces are primarily used in the automotive environment and refer to those surfaces which are visible in a product. In other words: A - class surfaces are those aesthetic/free-form surfaces, which are visible to us (interior/exterior), and have an optimal aesthetic shape and high surface quality.

DRAFT ANALYSIS OF CLASS A SURFACE:

• For plastic parts, the nominal angle value for draft analysis is 3 degree but even a 0.5-degree angle can be created for sub-assemblies like ribs and slots. (For Sheet Metal 7 degree angle is the nominal value)
• Insert - Analysis - Feature Draft Analysis.
• Draft analysis was carried out by pulling the compass to the tooling axis and an inverse draft axis was carried out if required.
• After setting the compass over the tooling axis the compass must be locked to a specific direction.
• If the surface was in green then the model passes or else further operations need to be carried out.

CLASS B SURFACE:

         The Class B finish is a quality finish with only minimal imperfections. A Class B finish is the most common finish for exterior surfaces. It is normally specified on surfaces such as external covers, panels, and parts that are fairly prominent.

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

Class C:

      The Class C finish allows more imperfections than Class A or B. Class C is often specified for interior surfaces not readily visible, surfaces that will be covered by another part when assembled, or surfaces which the Customer feels do not need to meet a high cosmetic finish.

CREATION OF CLASS C SURFACE:-

• The required outer edges of the A-Surface were extracted using Multiple Extract. Then for avoiding the patches the curve is smoothened using the Curve Smooth option.
• Then by using the sweep command the surface was created with the following feature controls,

1. Profile type – Line
2. Subtype – With Draft Direction
3. Guide Curve – Smooth Curve
4. Draft Direction – Tooling Axis
5. Draft Computation Mode – Square
6. Angle – 3 Degree
7. Angle Sector – Positive Downward (1)
8. Length – 20mm

• Then by using extrapolate command the edges were intersected between the surface corners which eases the trimming operation.
• Now the required portion of the C – surface were trimmed out.

FINAL BODY 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.

JUSTIFICATION FOR MANUFACTURING:

    Finally the Class – A, B&C surfaces with the Tooling Direction have been Published and the base bracket product is feasible for manufacturing