Week 8 - Challenge 2 - Switch Bezel Design

Aim: Draft analysis of a CATIA Component created using surface commands

Theory: -

Draft angle: A draft angle is a slant that is applied to each side of most features of an injection molded part. The angle, which is positioned to run toward the direction of a mold's pull and parting line, helps with releasing the part from the mold.



Draft analysis: The Draft Analysis allows the user to easily analyze a part for a proper draft angle. A Draft Angle describes the amount of taper for molded or cast parts perpendicular to the parting line. Find the Draft Analysis in the Tools tab. Draft Analysis is applicable for 3D part models.



Tool Axis Creation: -

In Molding, machine arrangement is given to open the mold along a direction which is known as Tooling Direction.

1. Likewise in our model, we first create a line from the pocket side walls:-






2. Then we create the line from the front walls, and since we do not have a close contour, we take to make a line at an angle greater than the draft angle to provide appropriate inclination.




3. Now we create the bisecting line from the two lines we have created as of now.



4. To check if this Bisecting Line will actually work as a tooling axis we see the top view of the line to see if all the 3 surfaces in the pocket can be seen or not.




Draft analysis:-

Standard Measurements:

Model Thickness: 2.5 mm
The minimum Draft angle provided: 3 deg angle


Class A surface Draft analysis:-



Final Body draft analysis:-






Note: In the first image, the draft angle is taken at 3 deg angle, and at the value of the edge is showing that the draft angle is between 0-3 deg only, as at some points on the C surface despite giving a 3 deg inclination, there is a deviation of only 2.977 deg as shown below, thus in the final image 2.9 deg is taken.



A different view of the draft analysis:-



Front View: -



Back View:-



Side View: -



Top view:-



Note:

Green Surface: Denotes that the model satisfies the required draft angle
Blue Surface: Denotes that the model draft angle is below the required draft angle.

Different surfaces:-

Class A surface:



Class B surface:



Class C surface:




Conclusion: Draft analysis is a very essential tool for manufacturing a plastic product using Core and cavity manufacturing techniques, hence draft angle should always be provided appropriately.