Week 9 - Attachment Feature Creation - Challenge 2

Door Trim with Dog House Attachment

Objective:

Create the Dog House for the Door Trim considering the design rules mentioned below.

• Take the Thickness of the component to be 2.5 mm

• "C" is where the doghouse contacts the backside of the surface.

To design the Door Trim first you need Class A Surface, if you have Class A Surface means you can create the tooling axis and do further design.

Given Class A Surface:

Class A surface is the outer most surface of the component, it is an aesthetic surface. It is also called as Strak. As a designer we don't have rights to modify the class A surface without permission.

Then we have check the class A surface whether it is joined or not by using boundry command if the boundry command shows only the the outer edges means we can work on class B otherwise we have to correct class A then only we can work on Class B.

The above image is the Class A Surface. Here, I gave different colors to different faces to crate the B surface easily.

Tooling Axis:

Tooling axis is very important to design a product. It is nothing but the direction of the molds open close and whether it is moves in the x, y or z direction. First we have to decide which direction is probabily suitable for the particular product. Once we get the Cass A Surface, we can check the surface and able to create the tooling direction.

Procedure to Create the Tooling Axis:

• First we have to create a point on the flate face or circle midpoint to create a line here i chose the bowl flat face.
• Once we created the point means we can create a line (Dummy axis) on the point in the suitable direction. We can find the suitable direction by simply see the object from x,y and z directions. If the object is fully visible from one of the direction means that is the line direction.
• After finding the direction just create a dummy axis and axis system.
• Then intersect the part with yz plane and create an bisecting line using the side angular lines which might create a problem.Do the same step in the xy plane to create an another line.
• After creating the two line which might create a problem, then draw a biseting line using the two bisecting line that we drawn from the yz and xy plane.
• Finally the tooling axis is created by using the Bisecting method.

Side Core Tooling Axis:

The Dog House inside portion will not clear the draft analysis with the main tooling axis. So, we have to create tooling axis for side core.

• To create the side core tooling axis we have to create a point-direction line with the help of main tooling axis pont and the direction of the side core movement(x-direction).

Draft Analysis:

Draft: Draft is used to remove the component fom the core and cavity. It will reduce the wear in component and molds so the the life of core and cavity will increase.

Draft Analysis: The Draft Analysis allows the user to easily analyze a part for proper draft angle. A Draft Angle describes the amount of taper for molded or cast parts perpendicular to the parting line.

The minimum draft angle ranges between 0.5 o 3 degree. Mostly 3 degree angle is widly used to make many components.

Class A Draft Analysis:

Procedure to do Draft Analysis:

• Once we created the tooling axis means we can do draft analysis. First we have to switch the view mode to shading with material.
• After switching to shading with material mode we can now click draft analysis tool. Then we have to place the compass on the tooling axis by clicking and draging the compass red dot.
• After placing the compass lock the direction and click the surface to do draft analysis.

• From the above image we can see that the green area has the draft angle above 3 degree. Here there is no red color in the surface.
• The blue color surface indicates that the draft angle ranges between 0 to 3 degree (Exactly 0.5 degree).
• If the color is red means negative or below 0 degree. We can change the color and angle value by clicking the color and values. But green,blue,red are standard colors.

Final Door Trim With Dog House Draft Analysis:

Here also we are using the same methods that we followed in class A draft analysis but instead of class A surface we are choosing Final Plastic Component with additional features like ribs and screw bosses(Closed Part).

• From the above image we can see that the plastic component is clearing the darft analysis so that it is possible to manufacture this part.
• The green area has more than 3 degree angle so it is posible to eject the component from the mold without sticking to mold.
• The blue color on the dog house means the draft angle ranges between 0 to 3 degree but the actual degree is 1.5 degree we can check the individual spot degree by using analyses under the running point tool in the display of the draft tool.
• Here we can crearly see that the dog house inside portion didn't clear the draft analysis. So we have to create side core tooling axis for dog house to clear the draft analysis.

Dog House Side Core Draft Analysis:

Here also we are using the same methods that we followed in class A draft analysis and final component but instead of main tooling axis we are choosing side core tooling axis.

• From the above image we can see that the dog house inside portion also clearing the darft analysis so that it is possible to manufacture this part.
• The green area has more than 0.45 degree angle so it is posible to eject the component from the mold without sticking to mold.
• We can check the individual spot degree by using analyses under the running point tool in the display of the draft tool.

Class B Surface Creation:

Class B Surface is the inner surface it can be created by using the class A surface by using several surface features.

Basic Features used in Class B Creation:

• Offset
• Exract
• Trim
• Radius
• Sweep
• Join
• Extrapolate
• Multisection
• Extrude etc.,

Here, every single faces extracted from class A surface. Then untrimed and extrapolated. Finally joined by using jon or trim command.

Final Class B Surafce:

The above images show the process of creating the class B surface.

Class C Surface Creation:

The surface which is used to close the class A and clas B surface is called class C surface. Simply it gives thickness to the component. We can create the surface using the features mentioned in the below image or other features.

Here I used draft with tooling Axis in sweep command to create the class C surface. Besides, Multisectional surface and surface with reference sweep commands were used.

Commands Used to Create Class c Surface:

Class A+B+C Surface:

After the creation of all three surfaces we can join them together with join or trim commands.

Solid Plastic Component With Dog House Feature:

We created only surfaces but we need solid part, so after the creation of all surfaces we should do close surface from part workbench. Finally the Door Trim with Dog House feature is ready for manufacturing.

Publications:

It is used to easily find out the main parts like tooling axis, class A,B and C surfaces.

Dog House Creation:

Dog House:

Dog house is an engineering feature used in plastic trim design. Dog houses are used as supporting feature. Sometimes other engineering features like snaps; locators etc. are mounded on them to increase their strength.

Dog House Design Rules:

For Part Thickness 2.5mm

• Wall Thickness ,W = 0.70 * T = 2mm (Actual 1.75mm)
• Minimum Inside Draft: 0.5degree
• Minimum Outer Draft: 1.5degree
• Fillet on the inner side = 0.25 * T = 0.6mm (We can take 1mm)
• Fillet on the outer side = 1.25 * T = 3mm
• Fillet on the coring edges = 0.25 * T = 0.5mm
• Coring thickness, C = 0.40 * T = 1mm

Sketch of Dog House:

Dog House In Final Part:

• First, we have to sweep the sketch with draft direction.
• Then we have to close the top by using the multisection or other commands.
• We can thick the surface by using the thicken command in part workbench.
• After thickening, we We can provide inside draft and fillets.
• Then we can split the coring by using different methods. Here, I created the portion that I want to cut by using surface.
• Finally we can give all fillets.

Completed design in various orientations (Isometric, Front, Side, and Top View):

Conclusion:

The Door Trim With Dog House Attachment is created by considering all the design roles and draft analysis clearing the main and side core tooling axis.