Week 8 - Challenge 1 - Base Bracket 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 dummy tooling axis using one of 2 mostly used methods, i.e
> From a large circular contour
> From a large flat surface.




2. Then we take a plane and using that plane, we will create an intersecting geometry in order to trace the parts of the models which might be critical for the draft analysis.




3. Then we extend the surface which are at angles from the dummy tooling axis.




4. Now we create a Bisecting Line that bisects the other two lines thereby generating the main tooling axis.



Thus we specify the tooling axis, also while selecting the tooling axis, we must check all the possible axes and choose the one with the least amount of complexity throughout the process of molding while checking the safest way for ejection of the product with less resistance.

Draft analysis:-

Standard Measurements:

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


Class A surface Draft analysis:-



Final Body draft analysis:-



Different views 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.