Week 8 - Challenge 1 - Base Bracket Design

Challenge 1: - Base Bracket Design

Given surface

1] Tooling axis Creation

In injection molding, the Class A surface is first analyzed to determine the axis or tooling direction that separates the molds. Tooling direction is critical for plastic product design because it determines mold direction

Steps followed

On the extracted surface, a reference point is first created. The reference point is created in the center of the large circle. we can make the reference point for our requirements.

To plot clearance lines, a new axis system is used.

The planes on which we are creating our model to be selected along with class A were used to develop the tooling axis using the Intersection curve command. By which We will get the intersecting curve from which we will create two lines and we will use those lines to create the Tooling axis.

Two clearing lines were bisected to form the Tooling axis, as shown below.

The tooling axis's graphic properties are changed to identify the Tooling axis. We can change the thickness and the color of the line.

Concerning the 2 Lines plotted along the X plane, and Bisecting line is drawn using these lines. While creating we will use the above two lines to create a bisecting line.

2] Creation of Class A surface

The given Surface is Joined together, using the Join command.

3] A detailed report on draft analysis and the tooling axis creation.

DRAFT ANALYSIS

• For molded or cast parts, the draft angle is the amount of taper perpendicular to the parting line. It is measurable in degrees. Because plastic shrinks and sticks on molding surfaces as it cools, we draft the walls of the plastic part so that it ejects or breaks free from the molding surfaces more easily and without dragging. To reduce the risk of damage to the parts and ensure ejection, a functional injection molding part must have drafts on both the cavity and core sides

Nominal values for Draft angles

• 3 Degrees is a nominal draft angle
• 5 Degrees can also be manufactured. Increasing the manufacturing cost
• 7 Degrees is considered for Textured surface parts

Importance of Draft in injection molding

• Reduces the possibility of part damage due to friction during the release
• Reduces mold wear and tear
• Ensures a uniform, smooth, unscratched finish
• Ensures the integrity and uniformity of other surface finishes and textures
• Reduces overall cooling time by reducing or eliminating the need for unusual ejection setups

Steps followed for Draft Analysis

• The created part must be changed to the material mode in the display frame
• Compass is enabled and placed in the direction of the Tooling Axis
• The lock command is then used to fix the compass along the tooling axis
• Colour codes are classified and Draft angle is applied
• Running point analysis is used to display permissible draft angle

The draft analysis Dialog box

Creation of Class B Surface

It is the offset surface of the Class A Surface the offset value depends on the thickness of the material, here the offset value is 2.5mm

Class C surface

The surface that Joins both Class A and Class B surfaces are considered to be Class C Surface.

Class (A+B+C)

Here we combine all the surfaces into one closed surface using the Trim tool Command.

Conversion of Closed surface into Solid Part

Using Solid Command we convert the closed surface to a solid surface in the Part model

Isometric

Front

Left

Right

Top

Bottom

Tree Structure

Draft Analysis of Final Part

After the conversion of the Closed surface into a Solid Part, it is subjected to Draft analysis to check if the Part can be manufactured using the Molding process and meets all the Injection molding requirements.

When we will Input the draft angle as 3 deg we will get Class A as Green. ClassB as Blue. Class C as Red.

To see the bottom view.

When we will Input the draft angle as 2.9 deg we will get Class A as Green. ClassB as Blue. Class C is Green and some parts of it will be Red.

We can see some red parts in front.

Conclusion :

Hence the base bracket plastic component through the given class A surface and created the required Tooling axis and performed the Draft analysis on the model and also for the solid model. so this Draft analysis feature is very useful to check the Draft angle and can check whether this part makes any problem while manufacturing that product. And the nominal Drafting angle is 3 Degree so we need to design the part with a minimum of 3 Degree has the Draft.