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

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

DOOR HANDLE :

AIM :

Create Rib and Screw boss for the door handle considering design rules.

Objective :

• Create the Tooling axis by using the bisecting method.
• Design the class-B and class-C surfaces and join them.
• Create the solid feature by surfaces we create.
• Design the required Ribs and Screw Boss and analysis them.
• Perform the Draft analysis for the final component.

INPUT:

Given Class A surface of door handle with the thickness of the component 2.5 mm.

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 solid body
• Draft analysis of Solid body
• Engineering features Rib and Screw boss
• Draft analysis of Solid body with engineering features

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.
• Create a line at the centre points by using normal to surface type from line feature.

DRAFT ANALYSIS OF CLASS A :-

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.

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.

CREATING CLASS C SURFACE:-

For creating the class C surface once the B-class surface is created then form the A – Class surface the with the help of sweep command and with the tooling direction another surface is created intersecting the B Class surface created and then the surfaces are trimmed to get a single desired surface.

CLOSED SURFACE :

Draft anlysis for Close Surface

Ribs creation

Ribs are thin wall protrusions that extend perpendicularly from a wall or plane. They are usually found in clusters offering support to a plane that would have otherwise been too thick, but can also be stand-alone support for a single wall. They are commonly used to provide additional support and strength to a part. Thickness and location are essential to rib design.

First, the base surface where the rib has to be created is extracted using the Extract command. A positioned sketch is created and the profile for the rib is drawn.

• Desgin rules for Ribs 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

Sketches for Ribs

• The draft is applied to the sides of the ribs. As per the design rule, the ideal draft angle is 0.5 deg

• Then fillet is applied to the faces of the rib. As per the design rule, the fillet can be 0.25 mm.

Ribs

Creation of Screw Bosses

Screw Boss features are commonly found in injection molding designs. They are used to aid in the assembly of molded parts by providing a channel for a screw. Their primary use is to strengthen holes or slots in the surface present in the part model.

Design rules consider while creating a screw boss

• Thickness

• Draft

• optional radii

• Boss gussets

• Type of ejection

The construction process of creating the screw boss is explained below:

For thickness, the design rule is as follows,

Thickness,w=0.6*T

=0.6*2.5

=1.5 mm

Therefore, the thickness of the boss can be 1.5 mm per side.

In this case, we have considered the size of the screw boss as M06.

• Desgin rules for Screw boss

Sketches For Screw Bosses and Ribs for Screw Boss

Screw Bosses

Draft Anlysis for Closed Body

• Screenshots of the completed design in various orientations (Isometric, Front, Side, and Top View)

Iso-matric view

Front View

Side View

Top View

Multi View

Feature Tree

Conclusion

• TOOLING AXIS for the CLASS A SURFACE and MODEL is created
• CLASS B AND CLASS C surfaceis created from CLASS A surface
• SURFACE MODEL is created using CLASS A,B & C surface
• SOLID BODY is created from SURFACE MODEL using close surface
• RIBS AND SCREW BOSS are created considering the design rules
• DRAFT ANALYSIS is done on CLASS A SURFACE and SOLID BODY
• Publications: Use the publication option published the following
  • Tooling Axis
  • Class A, B, and C surface
  • SURFACE MODEL
  • SOLID BODY