Challenge

Door Arm Rest Design

AIM :

To create the Door Arm Rest Plastic component through the given Class-A surface.

OBJECTIVE :

CLASS A SURFACE :

Class A surfaces are those surfaces which are curvature continuous while providing the simplest mathematical representation needed for the desired shape and does not have any undesirable waviness.
The Class A surface is the used to begin the design of a product.
All the further intricacies of the component are created based on the Class A surface.

CLASS B SURFACE :

The Class B surface is created from the Class A surface , keeping the thickness of the component in check.
The Class B surface resembles an offsetted surface from the Class A.

CLASS C SURFACE :

The Class C surface is used to bind the Class A and Class B surface together inorder to form a closed surface.

PROCEDURE :

Creating Tooling Axis

Initially a base surface was extracted from the Class A to create a center point.
An axis system was created upon this point.
The Intersect feature was used to obtain a boundary of the Class A intersecting at the ZX plane.
Two lines were created from the boundary obtained and Bisecting feature was used to create the middle line.

Another Intersect was taken from the Class A with the YZ plane.
A line was created at the boundary obtained and a sketch was created at an angle to this line.
These lines were bisected to form a third line in the middle.

Creating Class B Surface

The B surface was created from three separate sets of surfaces which was finally trimmed together to form a single surface.
The required surfaces were obtained from the Class A surface using Extract command.
These surfaces were further expanded using Untrim and Extrapolate commands.
The Outer flange was created using the Sweep command.

This swept surface was further joined with the top surface using the Blend command.
It ensured the continuity of the outer flange with the top wall.

Further the side and base walls of the Class B were created usng the Extract, Untrim and Extrapolate features.
It was made sure that all the B surfaces created were Offsetted from the A surface with a thickness of 2.5 mm.

The Top and the Inner walls were then Trimmed to form a single surface.
The necessary extrapolations were created to make sure that the B surface extends beyond the A surface.

Creating Class C Surface

The Class C surface connects the Class A and Class B surface.
Initially the outline of the Class A surface was obtained using the Boundary command.
The Curve smooth feature were used to enhance the the obtained surfaces.
The Sweep surface feature was used along with, With reference surface option , selction the curve and the surface which was extraced earlier.
The angle was entered as 90 degree so that the surface protudes outside therfore intersecting the A surface.
The required portions were Extrapolated and Trimmed with the A surface.

Creating Solid Body

Finally the Class A, B and C surfaces were trimmed together to form a closed surface.
Using the surface created the solid component was obtained using the Close surface feature present in the part workbench.
The Tooling axis, Class A, B and C surfaces were published.

Draft Analysis

The Drafting analysis was performed using the Feature Draft Analysis command.
Using this command the compass was set on the main tooling axis and the Draft angle was changed to 3 degree.

MODEL RESULTS :

Feature tree

Front view

Top view

Side view

Isometric view

CONCLUSION :

Ship work like this
in your own course.