Week 8 - Challenge 3 - Switch Bezel Design

Draft Analysis

When a plastic component is made, we can observe that there is a draft angle given on each side from the base which is lesser than 90 degrees. This is because in the criteria of making a plastic material the mold should release the material when finished. if the mold surfaces are 90 degrees the material won't release from the mold because of friction due to contraction of material when cooled.

To resolve this problem we CAD engineers maintain a standard rule to design the plastic mold or die's in such a way that there is no problem while ejecting the plastic component. So a minimum of 3 - 10 degrees of draft angle is given to every plastic component while designing.

Draft analysis is performed on the given Class-A surface, and it is clearly observable that there is no negative draft on the surface.

Tooling axis creation

  The tooling axis is the direction of drawing a sheet metal where the finished component is easily ejected on a particular direction and axis. The tooling axis is important for removing the material when finished.

The tooling axis is created for the given class-A surface.

Creation of tooling Axis (Bisecting method)

1. Extract the base surface of the given Class- A Surface and create the center point of the Extracted surface.

2. Then create two sketches on two planes by taking the cross section of the given surface in the particular plane.

tooling axis created from the two lines using the cross section of the surface on y plane as bisecting line.

tooling axis created from the two lines using the cross section and also creating one with the help of cross section line of the surface on X plane as bisecting line.

And now by creating another bisecting line using those two plane sketches is the tooling axis for this particular Class - A surface.

Creation of Class - B and Class - C surfaceE

extracting the class - A surface without the fillets and then untriming and extrapolateing them to join them, and after that offset the surface to 2.5 mm thickness which forms as the Class - B surface.

And then filleting the edges to 12 mm

Class - C surface

By extracting the boundary of the class - A surface, the surface required for the class - C is obtained.

using the smooth curve option a smooth surface can be obtained by sweeping the line towards the direction of the tooling axis.

Triming and joining the all the class surfaces together

Final out put

Drafting of final surface 

using the close surface tool on the final surface

performing draft analysis on the final plastic solid model

Various views