Week 9 - Attachment Feature Creation - Challenge 2
DOG HOUSE CREATION IN DOOR DRIM
AIM
- To create dog house in the given door trim class a surface.

Creating a tooling axis in class A surface:
- The direction in which the mould open and closes is the tooling axis.
- Check the connectivity of the surface and ensure there will be no gap between the surfaces and then define the tooling axis.
- While creating a tooling axis give the tooling axis on a flat length surface or the surface which have a hole on it.
- Create a point on the surface where we are going to create the dummy tooling axis and using line command crate an axis. If there is a circle or flat length surface which is recommended.

Draft Analysis:
- The draft analysis technique is used to analyze whether our part model created in CAD is manufacturable based on the draft condition applied.
- Minimum draft angle is considered as 3 degree.
- step 1= enter part in Catia.
- step 2= Go to Material Mode.
- step 3= go for draft analysis.
- step 4= drag axis bar to the tooling direction of part.
- step 5= check for draft and make parting line as per analysis.

Create a class B surface:
- Class B surfaces are the secondary surfaces in plastic component design.
- In this model Class B-Surface is extracted from the A-surface and it is offseted at 2.5mm in downward direction.
- To create the class B surface, I considered the entire surface has 3 parts 'Rib-1, Rib-2, and Base surface.

create a class C surface.
- 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.
- C-Surface connects the class A-Surface and B-Surface. It is created using Sweep command. Boundry of the class A-Surface is swept along the tooling direction.

Closed body


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 houses are subjected to draft analysis to prevent breakage of the component during ejection from mould cavity. Dog house and other engineering components are built on B-surface.
- Thick sections waste material and are simply uneconomic. So solid shapes that would do the job well in wood or metal must be transformed to a 'shell' form in plastics.
- Tooling must be cleared for easy ejection of the component, from the core cavity. In order to clear tooling certain value of draft is given to the component. Minimum of 2-3deg is provides on all plastic components.
Dog house creation
step 1

Step 2

Step 3

Step 4

Step 5

Step 6

Step 7

Step 8

Step 9

- Finshed all the steps next thicken the surafce and draft the body . next give the correct fillet value and check the draft analysis.
Tree structure :






