Computer-aided design (CAD) is the process of using software to take an idea in your head and create a digital model of it. It has applications in manufacturing, testing, and graphic design. The step immediately following CAD is Computer-aided manufacturing (CAM) in the design process. The CAD process can currently be applied to 2-Dimensional (2D) and 3-Dimensional (3D) spaces. However, researchers are currently looking at the practical uses of 4-Dimensional CAD by using Virtual Reality.
It is interesting to note the distinction by others between CAD and graphics. The definition of CAD suggests that any computer software that can be used for design should be considered a CAD software. However, many individuals will argue that software used for graphic design are not CAD because they lack features such as constrained dimensions which make precision an issue for translating to CAM. The Inkscape Wiki argues that, for its 2D vector graphics software, a lack of precision, the ability to dimension, and an atypical workflow prevent its software from being a traditional CAD. For DaBL's purposes, all software and methods below have the necessary requirements to be considered CAD and can be easily used on our machines for CAM.
In addition to software, there are some hardware devices that can be purchased to assist users in design, such as graphic tablets. These devices emphasize the artistic aspect of design and are not necessary for the CAD that is usually used in the Design and Build Lab. However, users of the space are more than welcome to bring their own.
Types of CAD
2D CAD is the process of specifying lines points or shapes on a surface plane for which to create a sketch. These sketches can be used to model anything from architectural plans to simple coasters. Generally, one starts with drawing space of a specific dimension and continues to add to this plane. Some may offer a scale that will translate the drawing to a physical piece of paper which is necessary for things such as architectural plans which cannot be printed to original size. General vector graphics software can be used to create the necessary drawing for a CAM process such as laser cutting.
The obvious extension to 2D CAD is 3D CAD which adds an extra dimension to the work area. Instead of working on a flat plane, we work in a space. Many types of 3D CAD software exists which all take a different approach to how they model an object.
Types of 3D CAD
Both types of 3D CAD are used in what is called solid modeling which formed the basis of the subject. Since the goal of DaBL is to teach CAD with the extent of manufacturing an object, solid modeling is required to ensure the object is bounded in space and can actually be created.
This type of modeling relies on defining features, called parameters, that build upon each other to create an object. For example, a 4x4mm square is defined by the parameters of length and width. If we add a third parameter for height of 4mm, we get a 4mm cube. An important note about parametric modeling is that it can be modified. If we go back and modify the length and width to be 5mm and 6mm respectively, our cube becomes a 5x6x4mm rectangle. The parameters can be created and deleted by the user and serve to constrain certain aspects of the design.
At its core, this type of modeling does not impose relationships on any of its object bodies and relies on the user to manipulate aspects freely. The goal is direct modeling by which you make the changes that fit your design. However, many of these types of software do possess the ability to add relationships to aspects of the design. These constraints may include making features parallel or perpendicular. This technique usually lacks the timeline feature which allows parametric techniques to build off itself.
List of software
|Autodesk EAGLE||2D CAD||PCB Mill|
|Inkscape||2D Graphics||PCB Mill / Laser cutter / Vinyl Cutter|
|Autodesk Fusion 360||3D CAD||3D Printer / PCB Mill|
|Blender||3D Graphics||3D Printer / Media devices|
It is important to do some light research on what software may be best for you. For example, if you plan to create a very simple shape and know nothing about 3D CAD, TinkerCAD is the software you want to use. If you would like to create a more complicated shape and do not mind investing an hour or two learning the software, Fusion 360 is likely your best bet. If you would like to create a device with moving parts and be able to test its mobility in the software, Inventor is likely going to be helpful. And for character creation, animation, or simulation (stuff not always meant to printed), then Blender, Maya, and 3DS Max will be helpful. There are lots of options some of which are listed here and some are not. Be aware that the staff on hand may not be familiar with every software option.
- Computer-aided design on Wikipedia
- Solid modeling on Wikipedia