Week 11 - Final project
OBJECTIVE
Hear I received class A surface of a car door’s plastic trims .my objective is to develop the class A surface received into manufacturable product design following the OEM design standards using CATIA V5 surface workbench .
ABSTRACT
The project report deals with the steps and procedures followed while developing plastic trims for care door from a class A surface provided, using CATIA V5 surface workbench.it explains the method I followed for creating the main tooling axes, side core axes, Class B surface, class c surface and final closed body creations. It also explains the draft analysis performed to check the manufacturability of the products using injection moulding various plastic door trims such as map pockets,armrest,lower substrate etc were successfully developed in this project .
PROCEDURE
- class A surface
In automotive industry there will be a dedicated team who will perform the aesthetic designing of various components including the whole vehicle .they will create various concept sketches after ideation .after that , they will also create a class a surface of the product . this class a surface is then passed over to the NPD cad team. they will initially inspect the class a surface in order to check if the design is manufacturable or if it is following the engineering principles. if there are any issue about the design, they will contact the product design team and will ask to modify the class a surface in order to solve the problem. hear I received the class a surface as shown below.
PLASTIC PARTS:
1.MAP POCKET – UPPER PART
2.MAP POCKET – LOWER PART
3.ARMREST SPLIT PARTS
4.LOWER SUBSTRATE
- MAP POCKET -UPPER PART
Initially, I extracted the class a surface required for each part from the main input. then started working on them one by one. hear I extracted the class a surface of map pocket from input as shown below
Next main tooling axis was created by applying a zero-distance vale on the surface as shown below
Next, the surface was inspected using draft analysis as shown below .in industry, if there is any issue with the surface after inspection, engineers must discuss the issue with the aesthetic design team whom provide the class a for troubleshooting the issue. here I detected some issue, but as there were no design team for me to contact, I solved some of them by my self.
Class b surface development
Class b surface was created from the class a surface using extract / multiple extract and offset option. major surface of class a surface was offset at a distance of 2.5 mm thickness. fillets were applied after necessary calculations.
Class c surface development
Class c surface was swept along the boundary of class a using sweep option at an angle of 3-degree outwards with respect to tooling direction .in some areas 90-degree sweep was applied. Finally, all the swept surface were trimmed and joined together
Then, class a surface of map pocket and the class c surface were joined together as shown below
After joining class a and c surface ,it was trimmed together with the class b surface in order to form the closed surface as shown below.
A part body was formed using the closed surface. next step was the creation of mounting features for fixing the component on the lower substrate. (Holes were actually created after modelling all the components and heat stakes.)
A dog house was created with locating pin and fixed it on the b side by union trimming it with the map pocket upper part.
Dog house is an engineering feature used in plastic trim design. the primary function of a dog house is to avoid sink marks on the class a surface which may occur due to features such as a thick screw boss or rib on the back side of class a 
map pocket upper part with mounting features
2. Map pocket – lower part
Lower part of the map pocket was also created by following the same steps and procedures .initially class a surface as shown below
Then, I performed the draft analysis. the walls were below 3 degrees. if it is an industrial project ,we must discuss it with aesthetic design team in order to avoid this issue by modifying the surface . but it is acceptable in this project. green surface represents more than 3-degree angle
Then, as earlier, the class b surface was formed using class a surface. the offset distance was 2.5 mm as it is the thickness of the component.
class B surface (blue )
Class C surface was swept along the boundary of Class A using ' Sweep' option at an angle of 3 degree outwards with respect to tooling direction. In some areas 90 degree sweep was applied. Finally all the swept surfaces were trimmed and joined together.
Then class A and class C surfaces were joined together as shown below.
Next, class B surface was trimmed along with the class A& C join to form the final closed surface.
Closed surface
A part body was formed using the final closed surface. Draft analysis of the final closed body was successfully performed.
Next step was the creation of mounting features for fixing the component on the lower substrate. An additional flange was also created at the top portion were it comes in contact with the upper map pocket part. Then, mounting features were created for fixing the component to the lower substrate. Actually, the mounting features were designed after modelling all the components and deciding the position of fixing points. Heat stakes were used to fix the components.
Draft analysis of the final product including all the features were successfully performed.
- Armrest
modified the class A surface
Class B surface was created from the class A surface using 'Extract/MultipleExtract' option. Class B surface was offset at a distance of 2.5 mm thickness from the class A surface. Fillets were applied after necessary calculations.
Class C surface was swept along the boundary of Class A using ' Sweep' option at an angle of 3 degree outwards with respect to main tooling direction. Finally all the swept surfaces were trimmed and joined together.
class c surface
closed surface
Finally, a part body was formed and created attachment features on it. The attachment features were successfully cleared along the side core axis.
Draft analysis along main tooling axis
- Lower substrate
It is on the lower substrate all the earlier designed components going to fix at first. I extracted the surface for class A from the input surface.
Class A surface
Made a tooling axis for inspecting the class A and also for sweeping the class C surface.
Draft analysis of class A (normal view)
There were no issues detected on the class A surface. So I proceeded to further steps for designing the product. The surface was almost flat in shape. I offset it for 2.5 mm for creating the class B as shown in next page.
Class B surface
Class C surface was created using sweep option. Trimmed and joined all the surfaces of class C as shown below.
Class C surface
Then I joined both the class A and class C surfaces together and trimmed it along with the class B surface for creating the final closed surface.
Final trim of Class A&C join with class B surface for creating the closed surface
Then a part body was created using the closed surface and heat stakes with ribs were designed with 0.5 degree draft, on the B surface side for attaching the map pocket and armrest plastic parts. Also two doghouses were fixed on the same side for fixing the locating pins. Dog houses were fixed at a distance 3 times of width of its side wall from features or walls in front of it for clearing the lifter during injection moulding.
Draft analysis of the lower substrate
Final product
Armrest and map pocket parts attached to the lower substrate (Rear side view)
Armrest and map pocket parts attached to the lower substrate (Front view)
Design tree structure