# 2. Computer Aided Design

## Overview

Okay, so before I get into what software I chose to work with and what I modeled, I want to offer beginners a bit of background and some tips regarding CAD, focusing particularly on parametric design. My goal is to provide you with a comprehensive overview rather than detailed instructions for specific problems.

First, what is parametric design? I’m no expert but I’ve come to understand it as an approach within computer-aided design (CAD) that allows you to use parameters to define the measurements of a shape and manipulate its geometry and dimensions.

Let me give you an example of where parametric design might come in handy. Suppose I want to model a gear. I would need to define several measurements, such as the pitch diameter, bore diameter, face width, tooth profile, pressure angle, the number of teeth… I could define all of these with specific measurements, and that would be fine if I only needed to make one type of gear.

But what if I need to make several gears with different requirements? That’s when parametric design comes in. Essentially, you’re not just modeling a gear; you’re designing a gear-making model. This model allows you to produce any gear by changing its parameters. You need to think upfront about which parameters you'll want to adjust. Once you've done that, you only need to change the parameter you wish to modify, and the design will automatically adjust to those new parameters.

I hope that was clear. Now, I'm going to move on to the next topic:

## What software did I choose to use?

First of all, I use an M1 Mac, so I need software that runs well on Macs. I chose two free pieces of software: Fusion 360, which I already had my eye on, and Blender, which is open source and I already use for rendering. I had never used the parametric design features in blender so it was a new experience for me.

To familiarize myself with the two, I first attempted to model the same Lego brick in both using parametric design.

Why did I prefer Fusion's interface? Well this is what Fusion looks like:

And this is what blender's node system looks like:

Honestly it looks more daunting than it really is and fusion's looks deceptively simple, learning where to make your sketches in fusion is a little complicated when you start and node systems are really useful for some things so take these images with a pinch of salt

After this, I decided to focus on learning Fusion since I found its interface more intuitive for CAD and parametric design than Blender’s node system.

Looking for a tutorial showing how to make a lego brick I found a playlist of YouTube videos titled “Learn Fusion 360 in 30 days” so I decided to work through some of these videos to learn how to use more tools in fusion. Here is the link: **Learn Fusion 360 in 30 days.** I’ve done the first 6 but plant to finish all 30 since they are very clear and I really liked fusion.

## Final Project

After this, I decided to model what I think will be my final project. Following along with the first 6 tutorials made me feel like I could model anything; they seemed easy enough. But once you start thinking about how to apply them to your own design, you realize it’s harder than it seems, especially if you try to stick to your original design instead of adapting it to the tools you already know how to use. By the way, I think that’s a valuable tip: while learning, never compromise your design to fit the tools you’re familiar with. Doing so makes you complacent and hinders your progress, and leads to worse designs in the future.

## Renders

These were done in Blender using cycles, a procedural texture and an HDRI for lighting