Week 10 - Challenge 2- Attachment Feature Creation (Dog House)
DRAFT ANALYSIS REPORT OF DOOR TRIM
Introduction:
Draft Analysis is the process of analysing the designed plastic part if it has the drafting angles as per the requirement. In CATIA, draft analysis is done by the tool called Feature Draft Analysis. It shows the different draft angles available at different parts and says if it meets the requirement or not by various colour codes. In this example, a Door trim class-A surface is taken for the draft analysis study.
Objective:
To perform draft analysis for both Class A surface & finished part of the Door trim. By considering below rules.
· C" is where the doghouse contacts the backside of the surface.
· Doghouse wall thickness at the intersection of the part wall (C) should be 40% or less than the main wall stock (T).
· The height of (B) should be between 3.0 – 6.0 mm
Steps need to do before draft analysis:
1. Creating the main tooling axis:
The given part (class A) is first checked for its boundary to find if there are any gaps or openings or discontinuity in the boundary. If there is any boundary you need to close the boundary before go to further.
After completing the boundary check insert a point at almost the symmetric centre of the part and insert a coordinate system at the point. The coordinate system should be facing in all directions the same as the default coordinate system.
Before actually creating the tooling axis, we need to create an dummy tooling axis on the class A surface at a point we created earlier. Then by using bisecting line command we need to find the final tooling axis.
First, create a dummy axis on the ZY plane. By using the intersection command, we will create a reference for the tooling axis creation. With that reference line, by using the bisecting line command, we can create a dummy tooling axis for the ZY plane.
Since the dummy tooling axis itself cleared the draft test. So, we consider it as the main tooling axis. The below images show the main tooling axis for the given part. It can be made bold and the colour can be changed for better visibility.
2. Side tooling axis
For the dog house part we need to create a separate tooling axis. Create a point on the main tooling axis. With the help of point and X direction we can create a line by using line command(point-direction). This line is used for checking side core draft angle. The below images show the main tooling axis for the given part. It can be made bold and the colour can be changed for better visibility.
3. Perform draft analysis
Now, perform the draft analysis of the door handle. To do so, go to Tools > Analysis > Feature Draft Analysis. This tool has three groups of options, namely mode, display, and direction. First, the second icon from the direction group is selected, and the red dot in the compass is clicked and dragged to the part to be drafted. The line in the dragged element is matched with the tooling axis, and it is locked using the first icon in the direction group. It will define the tooling axis direction and lock it. Then click the door trim. It will create different colors on the main part. If the part is in green color, it shows the draft angle is ok. If it is not in the sense, then do correct the sketch of the tooling axis to correct it or check the commands used for creating the part. The final result shows that all areas in the door trim maintained a thickness of 2.5 mm and a 0.5 to 3 degree draft angle.
Screenshots of the draft analysis report for the given Class-A surface
Screenshots of the draft analysis report for the given door handle (with Dog House)
Screenshots of the solid model with the proper colour code of the draft angle in various orientations with tree structure (Isometric, Front, Side, and Top View)
