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

Door handle

CREATING TOOLING AXIS -

The Tooling Direction is basically the direction that the mold pulls a part. The mold is built in two separate pieces, basically. You have a Cavity side and you have the Core side. The Core pulls apart from the Cavity and that's the Dye line or the Tooling Direction.

By analysing the component the most easily ejectable direction is somewhere close to the Y direction,(might be inclined to it) so we have made a sketch on the XY plane of Axis System) to create a bisecting line considering the 2 faces which might be difficult to be tooled.

Then resultant tooling axis is created using the bisecting method.

DRAFT ANALYSIS on 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.

Ribs

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.

The extruded surface is thickened,

Thickness,w=0.4*t

=0.4 2.5

=1mm

Therefore, the thickness of the rib is 1 mm

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.

Now, we have to check for the Rib root thickness.

To check for the Rib root thickness, We have to take an Intersection with the YZ plane and the Door handle component. Once we get to the intersection we have to create a tri-tangent circle at the rib area and measure it. The value must be within 30% greater of the wall thickness.

SCREW BOSS

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.

Once the sketch is completed, then it is padded using the Pad'command. The height to diameter ratio can be 3:1

Next, the draft is given to the boss. As per the design rule, the draft given for screw boss 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

DRAFT ANALYSIS on Part body

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: Ribs & Screw boss angle is 0.5 degree

Completed design in various orientations

Isometric

Left side

Top view