Week 9 - Attachment Feature Creation - Challenge 2

DOG HOUSE DESIGN FOR DOOR TRIM

Aim:

To Create the Dog house for the Door trim considering the design rules and to perform the draft analysis for Class A surface and to create a final closed body and also to perform draft analysis for it.

Objective of the Project:

• Create the Tooling axis.
• Design the Class B and Class C surfaces
• Join Class A and Class C surfaces together.
• Trim the Joined surfaces with Class B surface.
• Use the Closed surface feature to make a solid body from the surface.
• Design the Dog house and analyse them.
• Perform draft analysis for final component.

Class A Surface:

Tooling Axis:

Class A surface is checked first to create the Tooling axis. Where to analyse where the mold pulls apart in injection molding. Tooling direction is essential for plasic product design as it desides the mold separation direction.

To create the tooling axis first we have to check the best suitable direction for tooling by using the compass. The direction is suitable for creating the tooling axis because in the Y direction most of the surfaces are clearing while performing draft analysis. Generally the Tooling axis is created using bisecting the line method but here we create a Line normal to surface in Y direction and considered for Tooling axis.

Draft analysis for Class A Surface:

After creating Tooling axis we do draft analysis, Before drafting we have to make sure that in view mode it is selected for the materials.

After selecting the feature draft analysis tool we drag the compass from its position to the tool axis. Then lock the compass, After that select anywhere on the component and it will give the result.

We change the angle to 2.9°.

Creation of Class B Surface:

While creating the Class B surface first we have to offset the Class A surface for 2.5mm distance outward then some the surfaces gives offset error and asks for offset without error surfaces and work on incomplete surfaces by using multi section and other commands to complete the class B surface.

Creation of Class C Surface:

To create Class C surface first we have to extract the edges from the class A surface with the help of multiple extract or boundary command in which we create a path for sweep of Class C surface.

We have to create all separate sweeps and join them together. Once all the sweeps are joined we have to join Class C surface with Class A surface.

Then Trim the Class B surface with Class A+C surface this will make sure that we get a closed surface. We can check it by using boundary tool, if its gives error the component is not closed.

Then we go for part design workbench and use the closed surface tool to create a solidbody.

Creation of Doghouse:

Dog house is an engineering feature used in plastic trim design they are used as supporting features. Sometimes other features are used like snaps, locators, etc. they are mounted to increase the strength of the product.

We have consider some of the design rules for Doghouse. They are,

• Consider the thickness of the part to be 2.5 mm.
• "C" is where the doghouse contacts the backside of the surface.
• Doghouse wall thickness at the intersection of the part wall ( C ) should be 40% or less than the main wall stock ( T ).
• The height of ( B ) should be between 3.0 – 6.0 mm.

Steps for Dog house creation:

Extract the surface on which we want to create the doghouse and create a plane which is normal to that surface. Create the sketch on that plane using Positioned sketch.

We create the closed upper surface of the dog house by using extrapolate, extrude, offset and trimming feature.

• 2mm Thickness is considered for the surface by using a thick surface feature.
• Now apply the fillet for the side wall and outer surface.
• Side core tooling axis is created in the X direction on the same point of main tooling axis.

• Give the draft angle to the inside walls and pull direction as side core axis.
• The height B should be between 3.0-6.0mm by considering design rules.
• Doghouse wall thickness at the intersection of Partwall (C) should be 40% or less than main wall stock (T).
• We offset 1mm from the sidewall by considering the design rule.
• Now trim the surface and split the surface with the part body.
• Now apply draft on the inside edge where the bottom cut is done.
• Apply the fillet to those edges.

Draft analysis on Dog house:

Before drafting we have to make sure that in view mode it is selected for the materials.

After selecting the feature draft analysis tool we drag the compass from its position to the tool axis. Then lock the compass, After that select anywhere on the component and it will give the result.

We change the angle to 1.49°.

Creation of Final Body:

We can place n number of Dog house or attachment feature on the component by using transition command. Here we place the 2 Dog house by transiting the Doghouses un door trim by Point to point method.

The Doghouses are attached to the main body using Boolean operation so the unwanted extended bodies are eliminated.

Draft analysis on final component:

• The final part which is created is to be changed to the material mode.
• Compass is enabled and aligned it with the tooling axis.
• The lock command is applied to fix the compass with the tooling axis.
• Colour codes are applied and draft angle is defined as 2.9°.
• Running point analysis is used to get the permissible draft angle.

Conclusion:

Hence, the Doghouse for the door trim was created by considering the design rules and the draft analysis is performed on the final component.

Screenshots of Multiple views:

Screenshots of expanded Feature tree: