How to create a 3D CAD model? -- Getting back to the basics -- FEAforall

OK, you may came here because you had an idea for a new kind of product and you want to understand how to transform your idea into a 3D model on computer…

You came to the right place 😉

I’ll tell you here some of the most important things to know when you start…

… because when I started learning to create 3D models the first time, there were a lot of things to understand!

So, that’s what I’ll try to talk about on this blog.

Hoping that you will learn from my previous mistakes and experience and get better at creating CAD models of almost any mechanical system.

Like when you start almost any new project, the first thing you should do is to ask yourself the right questions.

You see, having the right questions helps you a lot to get the right answers… 😉

So…

Why do you need a 3D model?

There are many possible applications you may want to do with a 3D model:

It can be to get a good way to represent your design into something that looks more realistic in 3D, so you get a better idea of how it will actually look once manufactured
Maybe you already have a physical object that you want to represent and you need to get it into a computer in order to do something else with it (Simulate it for example…)
Or perhaps you are a graphical designer and you want to show your projects to your clients in 3D…

It is important to ask yourself those questions, because the process to generate a 3D model may be different in function of what you want to achieve.

The different types of 3D models

If you are a graphical designer, your process to create a 3D model will probably be totally different from someone else…

Like an industrial product designer who wants to represent a mechanical product for example.

A graphical designer needs some tools such as Maya, 3D Studio Max or Blender (the open source variant) for example.

Those tools will help you to create a very realistic 3D model that looks like real and can be rendered into an almost “photo-like” quality.

If you want to represent a mechanical System though, then there is a specific way to generate a 3D model, which is called CAD (Computer Assisted Design)

This blog is more focused on the CAD aspect of 3D modelling, so that’s what I’ll be talking about next.

What is a CAD model?

In the past, when you wanted to make a part, you needed to draft it first by hand

you can still do that of course, but now there is much better…

Every step of the conception of a mechanical part can be handled with a software known as a CAD software.

There are many of them around, at various price points, depending what you want to do

The most known CAD software are Solidwords, Inventor, Catia, …

Those are the tools you will hear about in the industry (but you probably heard about them already 😉 )

So, what is a CAD model…

Well, it’s basically a 3D representation of all the geometrical shapes that will represent your final model accurately.

The good thing about CAD is that it helps a lot to create drawings!

You just have to design a CAD model directly into a software…

and pop!… click on a button and get your drawing

(that’s slightly more complex than that in reality, but not REALLY complex)

In the past, it just wasn’t so easy to create drawings…

when you had just a small change to do in your design, you had to re-do all the drawings by hand…

no need to say that designers weren’t making changes as quickly as they do now…

that’s one of the advantages of the technology I guess.

How do you create a 3D CAD model?

The way you will create a model inside a CAD software depends on what you actually want to do and the type of part you want to model.

If the part you want to model is a pure 3D mechanical part like this one, then you will have to go through a 3D modeling process.

But if your part is a slender part that is made of sheet metal, you may need to use a different type of CAD modeling like “surfacing” for example.

The typical way to model a 3D CAD model follows 2 main steps:

Creating a sketch or draft
Changing this draft in 3D using specific operations
The model can then be refined using specific operations that depends on what you want to do

I’ll talk more in details about the basic operations to create a 3D model

…because it requires to show more “visually” how it works 😉

So we will study together in other articles what “extrusions”, “boolean operations”,”translations”, “rotations” actually means…

(nothing difficult I know, but there are so useful tricks to know about each)

In fact, creating a 3D CAD model is more or less like creating a sculpture (or lego) 😉

You just have to use the right combination of actions in the right order