Industrial 3D Modeling Methods : an introduction (1/2)

By Jacopo V, consultant at AYES Italy

3D modeling is the process of developing a mathematical representation of any surface of an object in three dimensions via specialized software.

In any mechanical design project, there are two different 3D modeling methods which can be used: “Top-Down” and “Bottom-Up”.

The choice of the method depends on:

•  The characteristics of the product to be designed;
• External constraints such as dimensions, complexity of the assembly, process technology;
• Design Software used.

 Although it is possible that the project final design be identical regardless of the method selected, “Top-Down” procedure offers a higher level of flexibility (in terms of change management process), resulting in decreasing risk of design conflicts and errors.

Flexibility is the key to solid and easy-to-use product design, as it allows preserving the integrity of the final design purpose throughout the process.

The “Bottom-up” Method

“Bottom-Up” remains nowadays the best known and most commonly used modeling approach.

This is because it is the simplest, the most immediate and intuitive technique. This method is effective mainly in two cases:

• To assemble already designed parts of an object.
• To build small and rather simple assemblies.

The “Bottom-Up” method consists first in designing individually each component of the assembly.

Then the parts are connected to form larger components, which are interconnected to create a complete system.

One advantage of this design process is that it allows to clearly identify the variables that have an influence on the individual components, and thus, on the entire system.

The “Top-Down” Method

“Top-Down” 3D modeling approach relies on the principle that it is possible to deduce the design of the individual components of a mechanical ensemble from analyzing the final assembly characteristics.

These components are linked together through dimensional relationships and external constraints. This approach leads to establishing a logical and sequential chain gathering all the information involved in the study.

Next week we will continue this article exploring further the Top-Down 3D modeling method. Do not miss!