Week 8 - Challenge 1 - Draft Analysis on a Fan Cover
Why draft is necessary:
A functional part for 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:
1. 3 degree is nominal draft
2. 0.5 is minimum draft which increase cost of manufacturing.
3. 7 degree for textured faces
Steps involved in Draft analysis:
Step 1.
Merging of Class A surface. All surfaces should be continuity we can check it by using Join command or boundary command if there is gap then green color line will appear. So we have to make sure the surface is joined As shown below.
By this we can confirm that there is no gaps between the boundary.
Step 2:
We can create dummy tooling line for reference for best possible tooling axis using X,Y,Z.
Step 3:
Now we create Tooling Axis 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.
Step-4:
Making the 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.
Publication: We can Publish the tooling line and Class A surface to the output so that it can be used further for making thick body or Class B surface.
Step 6:
Draft Analysis
1) First we need to change the view parameters into customise mode with material checked.
2. Click on insert toolbar then draft analysis icon.
Now draft analysis tool will appear on the screen. It gives information about color coding mode, Display and Direction.
Mode: This option gives detials about color coding and with help of this we can set the parameters of draft analysis also if we want to change the draft angle value for analysis then we can change.
conclusion: The draft analysis for fan cover was done with 3degres of draft