Week 8 - Challenge 1 - Draft Analysis on a Fan Cover
DRAFT ANALYSIS ON A FAN COVER:
Objective: - To perform draft analysis to check if the part has given draft on all its faces. And to determine the tooling axis.
Draft: - it is a tool used in Catia to make the face taper with tooling axis. Tooling axis is the direction of mold part ejection.
Why draft Is necessary:
A functional part of injection molding has to have drafts facing both cavity and core sides to reduce the risk of damage to the parts and ensure ejection. As the molten plastic flows into the closed die and fills the cavity, the material shrinks inside the mold upon cooling and as a result grips the core without any taper, the part would come out scratched while increasing wear and tear on the mold and shortening the tool life.
Draft angle recommendations:
- 3 degree is nominal draft
- 5 is minimum draft which increase cost of manufacturing
- 7 degrees for textured faces
Steps involves in draft analysis:
Step 1.
Merging of class A surface. All surfaces should be connected no gaps should be there we can check it using join command or boundary command.
Step 2.
Now we analysis the best possible tooling direction using the X/Y/Z planes we create dummy tooling line for reference.
Step 3.
Now we create tooling clearance along X/Y direction using the intersection of planes with class A surface.
We intersect Class A surface with XY/YZ/ZX planes and create the reference lines on the surfaces which might face problem during tool ejection.
We make tooling direction in X-AXIS.
By following similar method, we make tooling direction in Y-AXIS.
Bisecting line concept:
With help of reference lines, we make bisecting line which is on the same plane as the reference lines but are in normal direction. They are the either vertical or horizontal lines at the point of intersection of reference lines.
Step 4:
Making of tooling direction line: When we get the tooling direction in both X and Y direction then we use bisecting line to generate the tooling axis.
Step 5:
Publish the tooling and class A surface we publish the output so that it can be used further for making thick body or class B surface.
Step 6:
Draft Analysis
1.We first change the view parameters into customize mode with materials checked
- Click on insert toolbar then draft analysis icon.
Now draft analysis toolbar will appear on the screen, it gives information about color coding mode, display and direction.
Mode: This option gives details about color coding and with help of these we can set the parameters of draft analysis also if we want to change the draft angle value of analysis than we can change the draft angle value for analysis then we can change.
Display option
1.In the first option is used to hide and show the color scale.
2.Second option is used for analysis under point it gives the value of draft with respect to tooling axis selected at given point of the surface, Circles indicating plane tangent to surface.
Direction
In this we set the compass on tooling direction once the compass is set on tooling axis, we lock it so that it does not change
Also, we can flip the direction of the tooling if the compass is not as per our tooling direction.
Final draft analysis:
As the surfaces are in green color this indicates that all the surfaces have draft more than 2 degrees along the tooling direction indicating that our part can be easily ejected along this tooling direction
ISOMETRIC
FRONT
SIDE
TOP
