Week 8 Part 9 Project 3 - Surface Design
SURFACE CREATION AND DRAFT ANALYSIS FOR DOOR SWITCH BEZEL:
Aim: To create a surface model of door switch bezel and add a thickness of 2.5mm to it, and also perform draft analysis to the model.
As a plastic product designer, there are some objectives to consider for designing,
- Inspect the Class – A – Surface
- Create a tooling axis
- Adding thickness by creating Class B&C Surfaces
- Perform Draft Analysis
1. Inspect the Class – A – Surface:
Ensure that there is no gap between the surfaces, so we need to check the connectivity of the part. If it is not merged properly, then we have to use the join command to merge all the surfaces into one part.

2. Tooling Axis:
It is the axis, in which the direction of the mold (or) core & cavity opens.
Before creating the tooling axis, we need to analyze the component. And then we have the check the best direction for the tooling.

3. Add thickness to the part:
Before creating a solid, we need to create class – B & C surfaces to form thickness.
Class – A – Surface: Main surface – It is the outer skin of the product which is purely an aesthetic model.

Class – B – Surface: Engineering surface where the other components are attached.

The offset of 2.5mm

Class – C – Surface: It connects the A&B surfaces along the tooling axis.


Trim those three surfaces to form one surface part.

Create a solid body from this closed surface.

4. Draft Analysis
The draft analysis enables us to detect if the drafted part is easily removed or not.
Create a compass for draft direction using the tooling axis.
Lock the draft direction and then select the component.

- The drafted angle of the green color surface is above 3 degrees.
- The drafted angle of the blue color surface is between 0 to 3 degrees.
- The drafted angle of the red color surface is below 0 degrees (negative).

Normally, the minimum draft angle for every component is 3deg. If the draft angle is below 3 degrees, it increases the manufacturing cost.
Result:
The final design is ready to manufacture using further processes.
