Door Arm Rest Week 8 Challenge
DOOR ARM REST
OBJECTIVE:
To design a door arm rest according to OEM standards.
REQUIREMENTS:
- Tooling axis and check for side core if required.
- Perform a draft analysis on class A.
- Creation of class B & C surface.
- Use closed body to create a solid body out of the final surface.
- Perform draft analysis on the final component.
GIVEN INPUT:
Class A:
Part Thickness : 2.5 mm
Side Door is given for reference:
CREATION OF TOOLING AXIS:
After checking for surface imperfections the tooling axis creation comes into picture.
In the pocket area taking the arc as reference,a middle point is created and using the point and also with the reference to the flat surface a line is created. That is said to be the main tooling axis.
DRAFT ANALYSIS ON CLASS A:
A min of 3 degree draft is required on all the faces of the surface to clear the draft analysis.
VARIOUS ORIENTATION OF THE DRAFT ANALYSIS:
Here some of the faces are depicted as red and blue which means it has a draft below 3 degrees. So a additional tooling axis must be created to clear the faces which failed here.
CREATION OF SIDE CORE AXIS:
Using the same point as reference but taking the rib surface as reference a secondary tooling direction is created.
DRAFT ANALYSIS USING THE SECONDARY TOOLING AXIS:
The draft analysis infers that the faces which failed to pass the previous analysis it is passed by the secondary tooling axis.
VARIOUS ORIENTATION OF THE DRAFT ANALYSIS:
CREATION OF B SURFACE:
For a component like door arm rest it is good to split and create the B surface and later trim the splits.
Here front and rear halves are created seperately with reference to class A
As this specific area is of reverse and normal radius continuing as a surface a different approach is taken to create the portion.
The intersection is taken then a line is drawn and made as tangent to the surface and taking the line which passes between the fillets as reference. 
Using sweep command,taking the line(which made as tangent) as profile and middle line as guide curve a swept surface is created.
Then the front end of the swept surface is blended to the top part of the door arm rest.
Initial Trim:
An initial level trim is done to get the top portion of the arm rest and respective fillets are given to avaoid varying wall thickness.
Now the pocket area is created and trimmed with the top portion.
Respctive fillets are given to get the desired class B surface.
CREATION OF CLASS C SURFACE:
Class C surface is the surface which joins the class A and B together.
For this component the flat surfaces are swept along the tooling direction with 3 degrees.
C surfaces for filleted areas are created using the sweep command taking the edge of the flat surface swept as profile and filleted edge as the guide curve
And in some of the complicated areas sweep cannot be done, so in that cases multi section surface command can be used to create the in between surfaces.
Final class C surface:
After the sweep,multi section,join and trim operations the final C surface is displayed below:
FINAL SURFACE:
Final trim is done by joining the class C and A together and trimming it along class B surface to get the desired part.
Different views of the Door Arm Rest:
Now using the close surface,a solid body is created out of the final surface.
DRAFT ANALYSIS ON THE FINAL COMPONENT:
Main Tooling:
Secondary Tooling:
TREE STRUCTURE:
CONCLUSION:
To conclude the class B and C surface of a door arm rest is designed considering all the plastic design rules and a major and secondary tooling direction is created for the class A and also draft analysis is done on class A as well as the final component.
Software used: CATIA.