What is CAD?

CAD, short for Computer-Aided Design, is a type of software used to create three-dimensional (3D) designs. It's widely used in engineering and other fields for making new designs and models. CAD has screens where you can draw in both 2D and 3D, which makes it easy to see and create things. It helps engineers and designers turn their ideas into real-life drawings quickly and easily.

Where to design?

There are several CAD software options available in the market, including Fusion 360 and AutoCAD. These programs are user-friendly and offer a wide range of features. For students, Fusion 360 is a great choice because it's free for college students. On the other hand, AutoCAD is a paid software option. Both programs have their advantages, but Fusion 360 is particularly beneficial for students due to its accessibility and cost-effectiveness.

Introduction To Fusion360

The first step to begin using Fusion 360 is to download the software from their website. If you're a student, you'll need to sign up using your student email to redeem one year of free Fusion 360 membership. After installing the software, launch it, and you'll be greeted with a screen prompting you to sign in. This will open your browser, but you'll only need to do this once. One of the best features of Fusion 360 is that you can work on it in offline mode. However, to save your designs to the cloud, you'll need to occasionally go online.

Getting Started

After login you will be see you worksurface its a 3-D plane having x- axis , y - axis, z - axis. To create any 3-D figure first you need to design a 2-D shape.
To draw/ sketch just click on create sketch feature in the toolbar.

Create Sketch:

When you click on sketch 3 orange planes will be displayed each on representing the 3 planes. Click on any one of them an the create Sketch tool bar will be opened in this there are many things you can create Some of them are:
Line:
Click on line and then click on the plane, now you can click anywhere on the plane to create a direct line till that point. If you click and drag a circular line is created. Shortcut for line is 'L'.

Rectangle:
Same thing as a line , It has 3 options one is two points similar to line click on one point and click any where else to create a rectangle. Other option is to create using 3 points in this as the name suggest you need to mark three points. And the last option is center point where you can create a rectangle using a single point. Shortcut for drawing a rectangle is "R"

Circle:
Similar to a rectangle it also has 5 options for creating a circle. one is simple create a circle using a center, second is 2 points same as rectangle, third is 3 points circle. The last two require you to draw line, it uses tangents to draw circle, two tangents and three tangents. Shortcut for drawing a circle is "C".

Polygon:
Simple just type the number on sides it creates a regular polygon.
Spline:
It creates curved lines the first part is straight w=after that you can bend it in any direction you need.
Arc:
Just creates an arc between two points or three points.
Ellipse:
Used to generate ellipse the first click is for the generation of major axis the second click for minor axis.

Making it 3D

After completing a sketch click on "Finish Sketch" then you can use the Extrude feature to extend the diagram outwards. The extract feature only works on closed figures.
Extract:
Click on the figure you want to extract and then click extrude feature. A pop up dialog box appears where you can see many options-

Type of Extrusion:
- Solid: Extrudes the selected figure as a solid object, maintaining uniform thickness throughout.
- Thin: Extrudes the selected figure as a thin object, allowing for variation in thickness.
Direction of Extrusion:
- Normal: Extrudes the figure in one direction only, typically perpendicular to the selected face or surface.
- Symmetric: Extrudes the figure equally in both directions from the selected face or surface.
- Two-Sided: Extrudes the figure in two directions, but not necessarily symmetrically; you can control the extent of extrusion on each side independently.
Operation Features:

These are options that define how the extrusion interacts with existing geometry:
- Join: Adds the extruded geometry to existing geometry, merging them together.
- Cut: Removes the extruded geometry from existing geometry, essentially cutting it away.
- Intersect: Keeps only the overlapping portion between the extruded geometry and existing geometry.
- New Body: Creates a new solid body from the extruded geometry, separate from existing geometry.
- New Component: Similar to "New Body," but typically used in CAD software that supports assembly modeling, allowing the extruded geometry to be treated as a separate component or part.

Other Features :

Loft: The Loft feature in Fusion 360 essentially creates a smooth transition between two or more shapes or profiles. It's commonly used in CAD (Computer-Aided Design) to create complex surfaces or bodies with continuous, flowing contours. By lofting between different profiles, users can easily generate shapes that would be difficult or time-consuming to create manually, enabling efficient design iterations and exploration of various design concepts.
Revolute : The Revolute feature refers to a type of joint used in assemblies. A revolute joint allows components to rotate around an axis. This axis is defined by selecting cylindrical faces or edges of the components you want to join. When you apply a revolute joint between two components, they become linked, and one can rotate around the axis relative to the other.

Revolute joints are commonly used to simulate hinges, pivots, or rotational connections between parts in mechanical assemblies. They are essential for designing mechanisms where rotational motion is required, such as in machinery, robotics, or automotive systems.
Sweep :

Sweep is one of the feature in Fusion 360 which creates an 3-D extrusion on the specified path for it two things are needed , first being the body and second the path. after have those click on sweep in the create box. The first selection for the body and second is path then using an arrow you can extend it to where ever you want.
Hole :
As the name suggests it used to create variety of holes on a surface of an 3-D objects it is useful for creating screw holes just select the surface and an blue print appears showing how the hole will be there are many kinds of hole type, tap type, and the drill this ensures you create an exact model.

Thread :
After creating an hole you need to make threads inside it this is used for that , in this you can edit the size according to exact measurements, you can even toggle an option to start threading after some distance. To start you have to select the face on which you want to create the threads.

Now using the things we learnt lets create a Hex-Nut:

Step 1 :
As we are designing a hex-nut first create a hexagonal shape using the sketch feature. Select the polygon feature and then edge polygon draw your desired length and click finish sketch.
Step 2 :
Now using the extrude feature extrude the hexagonal shape
Step 3 :
We need to create a hole next so do that using the hole feature, Make sure the hole is in the center and make it so it goes all the way through the body.
Step 4 :
Now the final step is to create the threading, select the inside face of the hole.

Summary :
From this blog, you learned about CAD and the software used in CAD. We discovered how to install and launch Fusion 360, how to use it, create sketches, turn them into 3D models, and utilize different features on those models. Finally, we practiced by designing a Hex-Nut. We will explore more features and projects in future blogs.

Getting Started with CAD: A Simple Introduction