Challenge

Week 8 - Challenge 4 - Coin Holder Design

VVaibhavkumar Chonde27 Mar 2021

CENTER CONSOLE COIN HOLDER

AIM: Create the Coin Holder Plastic component through the given Class-A surface. To begin with, the tooling axis for the given Class-A Surface should be created meeting the requirements of the draft angle and at the end perform the Draft analysis on the model.

Take the Thickness of the component to be 2.5 mm.

Tooling Axis:

It is the direction in which the component will be ejecting after the molding process is completed.
The direction of tooling axis should clear the maximum portion of the part.
It should be selected in such way that number of side cores will be minimum as it will add more cost to the process.

Why Draft angle is important:

However, they are a required feature. A functional part for injection molding has to have drafts facing both cavity and core sides to reduce the risk of damage to the parts and ensure ejection. As the molten plastic flows into the closed die and fills the cavity, the material shrinks inside the mold upon cooling and as a result grips the core. Draft angles should be at least 3° to facilitate the part ejection.

Reduces the chance of damage to the part due to friction during release.
Reduces wear and tear and chances of damage to the mold.
Ensures a uniform, smooth, unscratched finish when required.
Ensures the integrity and uniformity of other surface finishes and textures.
Reduces overall cooling time by lessening or eliminating the need for unconventional ejection setups.

Workbench and tools used

Generative shape design

Extract
Extrapolate
Join
Trim
Offset
Boundary
Edge fillet
Intersection
Sweep
Close surface
Feature Draft Analysis

Design Process in CATIA V5

Given Data,

Class A surface,

After importing the class ‘A’ surface, we need to check the connectivity between the surface with merging distance 0.003 mm.

Now we will be doing Draft analysis on Class ‘A’ Surface, for that we need tooling Axis.

Tooling Axis creation:

First, we will extract the base surface of class ‘A’ and on that create the point and then create Axis system at that point.
As these surfaces are complex and cannot clear the tooling axis. In this situation we need to communicate with class ‘A’ designer and here we are doing this just for practice purpose.
So that we are creating the tooling axis in Z direction.
This line is the Main tooling axis for our part.
After which we will be publishing the tooling axis and class ‘A’ surface.

Draft Analysis,

Insert -> Analysis -> Feature Draft Analysis
Keep the view mode to material.
Drag the compass (Direction – compass) on the tooling axis and then select proper direction and lock it.
Giving draft angle as 3 degree.

‘B’ Surface Creation:

Extract Class ‘A’ Surface.
Untrim extracted surfaces.
Extrapolate to some extend eg. 30mm.
Use trim and select proper surface.
Offset inward at 2.5 mm
Use edge fillet, for inside fillet formula is Class ‘A’ surface Fillet – Thickness or Class ‘A’ surface Fillet + Thickness

‘C’ Surface Creation:

Take outer boundary using Boundary command of class ‘A’ surface
Also extract the outer surface for reference purpose.
Use sweep command to create surface using the extracted boundary and the reference surface.
Give the sweep surface angle as 90 degree and extend the surface up to 3 to 5mm and select appropriate direction.
Sweep – profile type ‘line’ – subtype ‘with reference surface’
Do same steps for the cut-out.