Week 9 - Attachment Feature Creation (Ribs & Screw Boss) - Challenge 1

AIM:
Create the RIB and SCREWBOSS for the Drill Handle considering the design rules mentioned in the video.

STEPS TO BE FOLLOWED :

• Creating the tooling axis.
• Draft analysis of Class A surface.
• Creating Class B surface.
• Creating Class C surface.
• Close Surface and Create solid body.
• Draft analysis of Solid body.
• Engineering features Rib and Screw boss.
• Draft analysis of Solid body with engineering features.

CLASS A SURFACE:

In automotive design, a class A surface is any of a set of free form surfaces of high efficiency and quality. It gives the aesthetic of the component which is created by the styling team and gives to the part design engineer to create the part with all engineering aspects.

CREATING THE TOOLING AXIS :

• Class-A surface is first analyzed to create the tooling axis or tooling direction that molds pull apart in injection molding. Tooling direction is important for plastic product design as it decides the direction for mold separation.
• First check the connectivity of the given Class A surface by using the Boundary or Join feature to visualized and repaired the open edges of the surface.
• And then, analyse visually the best suitable plane or surface for tooling axis.
• First check the connectivity of the given Class A surface by using the Boundary or Join feature to visualized and repaired the open edges of the surface.
• And then, analyse visually the best suitable plane or surface for tooling axis.
• TOOLING AXIS is created by bisecting the axis created on two intersections .
• The best tooling direction for the class-A surface is along y-axis direction.
• Flat surface on the center part is extracted for creating the tooling axis in y direction
• Then a line is created by BISECTING METHOD with the point and direction along y axis.

DRAFT ANALYSIS OF CLASS A SURFACE:

The Draft Analysis command enables you to detect if the part you drafted will be easily removed. This type of analysis is performed based on color ranges identifying zones on the analyzed element where the deviation from the draft direction at any point, corresponds to specified values.

• Before going to drat analysis go to customized view parameter >under mesh >check material and then click ok.
• Now for draft analyses go to insert » analysis » feature draft analysis.
• Use the compasss to define the draft direction.
• In the colour scale change the draft angle to 3 degree.
• The component changes to green in indication of passing draft angle.
• Use running point to check the angle on the component.

NOTE: Some part of CLASS A SURFACE does not cleared the draft analysis this may be due to improper CLASS A SURFACE.

CREATING CLASS B SURFACE:-

• Extract the surfaces from the class A using multiple extract and untrim them.
• Use Extrapolate to make sure that all the untrims are properly intersected to trim and offset the surfaces to 2.5 mm to create the thickness.
• Fill the patches which are not offested by the using the commands like extract,boundary and multi-section surface.
• Then join the patches to the offseted surface using the command.So will get the complete class B.

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.

CLOSED SURFACE :

Draft analysis for Close Surface:

DIFFERNT VIEWS OF SOLID BODY:

RIB CREATION:

Next, the profile is extruded, to find the height,h=Wall thickness * 5

=2.5*5

= 12.5 mm

Therefore, the height is 12.5 mm

The extruded surface is thickened,

Thickness,w=0.4*t

=0.4 2.5

=1mm

Therefore, the thickness of the rib is 1 mm.

SCREWBOSS CREATION:

• Draft - 0.5 degrees on the walls of boss
• Thickness - Typically 40%* of the nominal wall at the base.
• Height to Diameter Ratio - 3:1
• Radii - 0.25mm maximum radii.

FINAL BODY VIEWS:

FINAL BODY DRAFT VIEWS:

NOTE: RIBS and SCREWBOSS is blue in color due to the draft provided by us is 0.5 deg which is less than 3 deg.

TREE STRUCTURE:

CONCLUSION:

• Closed body with RIBS and SCREWBOSS is created by following the required specifications.
• Draft analysis is performed on CLASS A SURFACE, CLOSED BODY AND FINAL BODY.