Challenge

Week 9 - Attachment Feature Creation - Challenge 2

HHarshit Bhavikatti1 Mar 2023

REPORT

AIM :

Create the Dog House for the Door Trim considering the design rules mentioned in the video. Consider the thickness of the part to be 2.5 mm

OBJECTIVES :

"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

INTRODUCTION :

DESIGNING METHODOLOGY :

Class-A surface means visible surface. It gives the aesthetic of the component which is created by the styling team and gives to the part design engineer to create the part with all engineering aspects.

Given CLASS-A surface

NOMINAL PROCESS IS TO CHECK FOR THE QUALITY OF THE CLASS_A SURFACE TO GO FOR THE FURTHER PART CREATION .

DRAFT ANALYSIS OF CLASS_A :

Tooling axis creation

Check the best possible tooling direction by manually adjusting the compass.
By analysing it is found that y axis as tooling direction would clear most of the faces without any difficulties.
Now extract any surface and create a mid-point on it.
Then create a dummy axis creating a line on the point and direction along the y axis.
Perform draft analysis to find whether the given axis clearing the draft analysis. If not create a new tooling axis.

MAIN TOOLING AXIS :

SLIDER TOOLING AXIS :-

CLASS-B CREATION :

Class-B surface means thickness of a part it is not visible and is inside part. In other words, Class-B surface is a surface below a certain thickness from the class-A surface. This is the surface that contains engineering aspects of a model.

Create offset surface of CLASS-A about 2.5mm inward direction.
Check for the discontinuity and rework on the offset surface using extract, multi-extract, multi sections surface.

DRAFT ANALYSIS : B_SURFACE

CLASS-C CREATION :

Surface that joins class-A and class-B surfaces is class-C surface. Class C is often specified for interior surfaces not readily visible, surfaces that will be covered by another part when assembled

Create the sweep surfaces with reference to surface and tooling axis by multi extracting the CLASS-A boundary
Join the sweep surfaces by using commands like extrapolate, trim, multi section surface.
Finally join all the sweep surfaces and ensure the continuity of the CLASS-C surface.

DRAFT ANALYSIS : C_SURFACE

FINAL_SURFACE _BODY_CREATION :

For creating the Finals door trim surface, join the CLASS-A and CLASS-C surface together.
Then Extrapolate the B surface little bit outward direction to make sure that there would not be any gap when trimming with joined surface.
Then trim the extrapolated CLASS-B surface with Join surface (CLASS-A and CLASS-C)

LASTLY_CONVERTING_FRON SURFACE _TO SOLID_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.

Design procedure of dog house:

Make a rectangle to enclose the screw boss in it but make sure it is open from one side.

Sweep it with tooling axis as the pulling direction and give a minimum draft of 1.5deg inwards.
Enclose it from the top by using the off-set of extract of the base of class-A surface. The offset distance determines the height of the dog house, so give it according to the design rules.
The inward face of the dog house should be drafted too, so give them a draft of 0.5deg.
Use the same extract of class-A, and offset it at the height of 3mm-6mm. 8. Extract the inside faces of the dog house and offset it outwards at 0.4't and trim them togather.
Go to the part design and split it with the model
After that we will fillet the entire model of the dog house and add it to the main body
Later we mount the screw boss on the dog house by translating it