Week 8 - Challenge 3 - Coin Holder Design
AIM
The aim of this project is to develop the product design of the COIN HOLDER with the help of the class A surface following the OEM standards.
OBJECTIVE
To 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.
Introduction
Class A
Class A surface is the term mainly used in automotive design industry. It describes the final production surface data for the aesthetic parts of the car.
Class B
Class B surface is the secondary surfaces which is not visible normally. These must be smooth and "error-free" as well, but are not held to the standards that class A surfaces are.
Class C
Class C surfaces are the backside surfaces that can have tool marks, flash and other imperfections without hurting appearance, function, etc..
The steps involved in creation of this project are:
1. Bringing the class A surface of the coin holder in Catia v5 software.
2. Determining the tooling axis for the coin holder.
3. Creation of class B surface.
4. Creation of class C surface.
5. Joining all the class A, class B and class C surfaces of the coin holder.
6. Building closed surface after joining all the surfaces.
7. Draft analysis on the coin holder.
METHODOLOGY:
In this model we have focused on the following things:
- Tooling axis
- Draft analysis
- Class-B surface
- Class-C surface
- Making a solid model from surface.
Following tools were used to reach the final step:
- Extract
- Un-trim
- Trim
- Extrapolate
- Offset
- Edge fillet
- Face fillet
- Boundary
- Sweep
- Join
- Close (part design)
Procedure
Below is the class A surface which was incorporated in the Catia V5 work bench to work upon.
Determination of Tooling axis (Normal to Surface method) and Draft analysis at 3 Deg for the above class A surface.
Creation of Class B surface
The class B surface is created by extracting each surface of class A surface and then untriming them.
After this an offset of 2.5 mm is given in the downward direction to generate the class B surface.
The surfaces are then extrapolated with a certain distance in order to create cross section among the surfaces to perform trim operation.
Surface trim and Fillet option was used to give the class B surface required shape.
Creation of class C surface for coin holder
For the creation of class B surface, first the boundary of the class A surface is extracted using Multiple extract feature.
After this sweep option is used to create the sweep along the with reference surface at 90 Deg.
Class A surface and the class C surface are then joined together to get desired shape.
After this operation, class A,class C surface are trimmed with class B surface together to give the plastic product a mouldable shape.
After ensuring that the surfaces formed are completely closed, the closed surface feature is used to create the solid mould of the coin holder.
Draft Analysis
When the design is complete, draft analysis is done on the component to check the the product which we have designed is manufacturable or not
After draft analysis is done we can observe that the green colour shows that the drafted walls of the coin holder are above 2.9 degrees which is a permissible cirteria to manufacture in injection moulding.
What material is used for coin holder ? why?
Polypropylene is used for coin holder because it offers excellent fatigue resistance and elasticity, by securing it a well deserved reputation for Toughness and durability.it has high flexbility properties, lighter density and adapt to a range of facbrication techniques.
Conclusion
1. Class A, Class B and Class C surfaces are created following standards of automotive industry using Catia V5 software.
2. Draft analysis was performed on the coin holder and it was observed that draft was under permissible limit for the manufacturing of the component using injection moulding process.