Week 8 - Challenge 1 - Draft Analysis on a Fan Cover

DRAFT ANALYSIS REPORT OF FAN COVER:

OBJECTIVE: To perform draft analysis to check if the part has the given draft on its all faces and to determine the tooling axis.

DRAFT: Draft is a tool used in CATIA to make the faces taper with respect to the tooling axis. Tooling Axis is the direction of mold part ejection.

Why draft is necessary?

When developing parts for plastic injection molding, applying draft (or a taper) to the faces of the part is critical to improving the moldability of your part. Without it, parts run the risk of poor cosmetic finishes and may bend, break, or warp due to molding stresses caused by the plastic cooling.

Draft Ange Recommendations:

• 3° is Nominal Draft.
• 0.5° is a minimum draft which increases the cost of manfacturing.
• 7° for Textured Faces.

Procedure:

• First, Check the Class A surface that it has no gaps. To check, use JOIN or BOUNDARY command. In JOIN, it will highlight the surfaces individually if there is more than one. In BOUNDARY, it will create a boundary line along all the edges of the surface and after hiding the Class A Surface we can check if there is any unexpected line.

• Now we analyze the best possible Tooling Direction using the X/Y/Z planes. For that, we will create a Dummy Tooling Axis. To create a tooling axis first we extract a point from the boundary line of the center hole and then using that line we will create a line along Z-Axis.

• After analyzing, we realized that we can create a tooling axis along X/Y plane.
• Now we will create a New Axis System using the point from which we created the dummy line.

• Now we will create an intersection of the surface using XZ Plane.

• From the intersection, we will create 2 lines.

• From the 2 lines, we will create a bisecting line and name it Tooling Clearance X Direction.

• Now we do the same using YZ Plane. Will do the intersection of surface, then create 2 lines and then a bisecting line(Name it Tooling Clearance Y Direction).

• After this, Using both the bisecting lines we will create another bisecting line and name it Tooling Axis.

• Using the Tooling Axis we will do Draft Analysis.
• We can make a shortcut to access the Class A Surface and Tooling Axis using Publication. To use Publication go to tools option and at the end select publication. A dialogue box will appear, select the Class A Surface and Tooling Axis from the tree. A shortcut will the created under the publication section at the end of the tree.

• Go to Insert>Analysis>Feature Draft Analysis. Two Dialogue boxes will open.

• Under the 'Direction' Tab (Highlighted in Black) select 'uses the compass' option (Highlighted in Red)

• Place the compass on the tooling axis and lock the direction using the 'Lock or Unlock the draft direction Button on the left side of the 'uses the compass' button.

• Now select the surface. Using the dialogue box on the right side you can change the draft value. As the surface is showing green color it is OK for the draft. IF it is not OK for the draft it will show other colors for undercuts and where the draft is required.

Isometric View

Front View

Side View

Top View

Draft Analysis

Tree