Week 9 - Project - Master Section Development

Aim:

The main objective is to create a Solid with the Attachments such as Ribs, Locators, and Doghouses using the given Class-A surface.

Methodology:

1. Opening the file.
2. Checking the Class A surface Tooling Axis.
3. Creating the Tooling Axis.
4. Performing the Draft Analysis.
5. Creating the B Surface.
6. Creating the C surface.
7. Joining the Surface
8. Creating the Solid
9. Creating the 4-way locator.
10. Creating the Doghouse.
11. Creating the Ribs.

Theory:

B pillar:

Pillars are the vertical or near-vertical supports of a car's window area or greenhouse designated respectively as the A, B, C, or (in larger cars) D-pillar, moving from front to rear, in profile view.

In the B Pillar of the 4 door, it is a closed steel structure welded at the bottom to the car’s rocker panel and Floorpan, as well as on the top to the roof rail or panel. This pillar provides structural support for the vehicle’s roof panel and is designed for Latching the front door and mounting the hinges for the rear doors.

Procedure:

1. Checking the Class A Surface Tooling Axis:

• Initially, the model is opened using the Open Command. Once, the model is opened, we check the given Class-A surface of the given B-pillar Components.
• We rotate the model to see at which plane the whole surface can be seen completely.
• Here we can see the whole model on Y-axis.

2. Creating the Tooling Axis:

• Since we already know that the whole Surface is seen at Y-Axis, the direction of the tooling axis is in the Y-axis.
• Now, the direction is known but the position is unknown. Therefore, the Base is selected.
• Once the base is selected, the Extract option is used. (Extract option can be found in Operation Toolbox in the Generative Shape Design)
• A point is selected on the extracted base and the point dimensions are given as ‘0’ such that the point falls on the center.
• A line is created in the Y-Axis direction with the reference of the point created.

3. Checking for Draft Analysis:

• Once the Tooling axis is created, the Draft analysis is done on the surface.
• To perform Draft Analysis, Go to the insert Menu >> Click Analysis >> Click Feature Draft Analysis option >> New Dialog boxes opens.
• Select the Elements as the Class-A Model and the Direction as the Tooling Axis using the Compass option to define a new direction of the draft.
• Click OK to check if all the surfaces come under the limits of 0 to 3 degrees.
• If the draft is more than 3 Degree then the surface will be shown as green.

4. Creating the B-surface:

• To create a B surface, we need to offset the Class-A Surface but the Surface cannot be the same as the Class A as it would create errors while the model is sent for prototyping.
• We start with extracting the Top surface and Offset it to the thickness of the model (that is 2.5mm). Now, extract the groove parts and the base part and offset it to the same thickness.
• Now un-trim the extracted surfaces and extrapolate the surfaces such that every surface intersects with the neighboring surfaces. After completing the extrapolating, trim the surface such that the extracted surface is similar to that of the class A-surface (without fillets).
• The surface then needs to be filleted as the Class A surface with the 2.5mm added or removed by fillet radius.
• To create the Flange, the master section can be used. Extract the line on the b surface and sweep it with an angle of 90 degrees initially and create the intersection line. 
• Now select the line and check for the angle and change the sweep angle similar to the master Section line and click ok.
• Join the Sweep created and the B surface and follow the same with the Class A surface.

5. Creating the C surface:

• After creating the B surface, the C surface needs to be created. To create the C surface, the sweep option is used.
• To create a sweep, there should be a boundary created to it. The boundary should be created separately as creating the boundary completely doesn’t create the sweep smoothly as the model contains the main unnecessary lines.
• To cover those, the smooth option is used to create the smooth surface and the Class A surface model is swept smoothly over the plane areas. Over the draft angled areas, the boundary should be created separately to create the sweep over that area.
• Now join the Class C surfaces together to create the surface.

6. Joining the Surfaces:

• Now, start with joining the Class A and Class C surfaces together.
• Next, trim the combined surface with the Class B Surface to create the final surface.

7. Creating the Solid:

• After creating the surface, go to the Part design option and create the solid using the closed surface option.
• The solid is created.

8. Creating the 4-way Locator:

• To create 4 Way locators, the ribs should be created intersecting with each other.
• Open the Sketcher Workbench and Draw 2 lines intersecting each other and constraint it by using the master section lines.
• Exit the Sketcher Workbench and Pad the Sketch with a thickness of 1 or 1.3mm.
• Chamfer the Ribs and give the Fillets to it.

9. Creating the Doghouse:

• To create a Doghouse, Create the sketch on the Surface face, such that there are 3 sides are created and constraint it.
• Exit the Sketcher Workbench.
• After exiting the sketcher workbench, Open the Generative Shape design and Sweep the Surfaces.
• Select the Guide Curve, the Tooling axis, and the Draft angle for the surface.
• Create a top layer as a closed body by using the Offset command. Now, join the surfaces together.
• Use Edge fillet command to give 0.25mm fillet region.
• After the Edge fillet is given use the Thickness tool in the Part body to give the thickness.
• Now to reduce the sink marks, the thickness at the merging section is reduced to 40% of the main tooling thickness.
• Now create an offset of the part to create the section.
• Trim that part with the Part body to remove the thickness.
• The Final Dog house is created.
• We can place the Locatorabove the Dog House and assemble to create the component.

10. Creating the Ribs:

• To create the Ribs, Go to the Sketcher workbench and draw a straight line on the face you want to create a rib and constraint it.
• Exit the Sketcher workbench and Open the Generative shape design and extrude the surface.
• Create a Solid component.
• Offset the Class-B surface to 5mm and split it to cut the rib surface.
• Now, union trim the rib to get the final Rib structure by removing the unnecessary faces.
• To create the Ribs next to each other with a distance of 50mm, Go to the Class B or Class A Surface and select a line to extract.
• Select the Points repetition option to create the Points on the extracted line and give the offset distance as 50 and select the curve line.
• Now copy the Part body and paste it on the main Tree Structure(Note: Paste it with the option “Paste Special >>Paste with the Link).
• Use the Translate option to move the copied rib part body from the starting point to the ending 50mm point. Click Ok and Union trim the model.
• Follow the above steps repeatedly to create the ribs on both sides.
• The Final Solid component is created.

Results:

The B-Pillar is created from a Class A surface with the B Side features.

Sketch Solving Status:

Tree Structure:

Final Structure:

 

Draft Analysis on Dog Houses: 

For Main Tooling Axis:

The draft angle given for the doghouse and the ribs are 0.5 degrees.

For Lifter Axis:

Final Draft analysis:

From Class A:

From Class C:

Errors faced:

There were many errors faced but the main error faced was while performing the Draft analysis on the surface. The Class A model didn’t clear all the errors and those errors were made it a hard task to clear those errors. The initial error was regarding the Tooling axis and the reduced draft angle around the corner areas and therefore, the tooling axis direction has helped to get fewer errors in that area but the error then occurs in some other areas. These areas have a draft angle between 0 to 3 degrees which is acceptable but the angles less than 0 should not be created.

Next, the rib areas were failing for the minimum draft angle and that error is resolved by making the Extrude direction to the Tooling axis.

Learning Outcomes:

• Learning how to create the B- side features using the master sections.
• Learned to create the Surfaces and Troubleshooting the errors such that the errors won’t be repeated.