Week 10 - Challenge 1- Attachment Feature Creation (Ribs & Screw Boss)
Class A suraface:
In automotive design, a Class A surface is a collection of free-form surfaces of high performance and quality.
It gives the aesthetics of the component developed by the styling team and provides the part design engineer to create the part with all the engineering features
Creating a surface class
Given that we have a class-A surface, the first step is to ensure that there are no gaps between the given surfaces.
We can check it with the help of view and parallel or boundary commands.
TOOLING AXIS:
A TOOLING AXIS is created by bisecting an axis created at two intersections.
The ideal tool direction for a class-A surface is along the y-axis direction.
A flat surface in the center section is extracted to create the tool axis in the y direction
Then created a tool axis with the point and direction on the y axis.
The TOOLING AXIS of the part is created
DRAFT ANGLE:
When creating parts for plastic injection molding, using a draft (or taper) on 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 the plastic may bend, break or distort due to molding stresses caused by cooling.
Equally important, the lack of draft can prevent parts from escaping the molds, which can damage not only the parts but also the molds—a costly and time-consuming detour
DRAFT ANALYSIS OF CLASS A SURFACE
Change the view to material mode for draft anlysis
draft analysis is done using featured draft analysis tool
Use the compass fucnction to aling the compass to the tooling direction and lock the direction using lock function in the draft analysis tool bar
the surface is showing green colour so that the surface clears the minimum draft angle of 3 degree
By using the analyses under the running pointwe can check draft angle on the individual faces. It shows how much draft on specific points when we move the cursor point.
Green colour - above 3 degree positive draft
Red colour -between 3 and 0
blue colour- below 0 degree
CLASS B SURFACE
Class-B surface means the thickness of a part it is not visible and is inside part. In other words, the Class-B surface is a surface below a certain thickness from the class-A surface. This is the surface that contains engineering aspects of a model.The Class B finish is a quality finish with only minimal imperfections. A Class B finish is the most common finish for exterior surfaces. It is normally specified on surfaces such as external covers, panels, and parts that are fairly prominent.
B SURFACE is created by Offseting the class-A surface to 3mm inward direction.
patches are created while offsetting the surface. Rework on the patches using the features like extract, multi-extract, sweep, multi-section surfaces, extrapolate.
the boundary command is used to identify and highlight the patches
class B surface is created
CLASS C SURFACE
The surface that joins class-A and class-B surfaces are class-C surfaces. Class C is often specified for interior surfaces not readily visible, surfaces that will be covered by another part when assembledThe Class C finish allows more imperfections than Class A or B. Class C is often specified for interior surfaces not readily visible, surfaces that will be covered by another part when assembled, or surfaces which the Customer feels do not need to meet a high cosmetic finish.
The method used for class c surface is sweep feature
Since it is a complex class-A surface, we cannot create the class-A boundary curve and sweep in a single stretch .
small sections are created using multi-extract command and then create sweep of 90 degree with reference to the surface option.
SOLID SURFACE:
CLASS A and CLASS C is JOIN together
CLASS B is trimmed with CLASS A AND C
SOLID SURFACE FORMED
RIB DESIGN:
SCREW BOSS :
