What is CAD?

posted by Margaret Potagal

If you have ever been to the DaVinci lab, or even seen the display cases in the 100s, you have probably seen things that were originally designed using CAD. The first time I heard the term “CAD” was this past year when I joined the NHS Robotics club. CAD stands for computer assisted design, and it is basically a 2D and 3D modeling software. For many of us, we remember painstakingly measuring using rulers and protractors to draft a model of a building in a middle school math class to teach us about practical applications to algebra and geometry. As we all figured out, this process is painstaking and prone to lots of erasing and revision as you come up with new ideas or catch calculation errors or lines not perfectly perpendicular to each other. A lot of these issues can be solved, and the design process itself can be greatly expedited, with the use of CAD.


CAD software first started being developed in the 1960s. Key contributors were Patrick Hanratty, who joined General Motors Research Laboratories where he helped develop DAC (Design Automated by Computer), and Ivan Sutherland who broke new ground in 3D computer modeling and visual simulation, which is the basis for CAD. His 1963 Ph.D. thesis at MIT was “Sketchpad: A Man-Machine Graphical Communications System.” It allowed designers to use a light pen to create engineering drawings directly on a CRT. In the 1970s, CAD software became available on the public market, but computers could only really run it for 2D designs. As algorithms and more powerful computers were developed in the 80s and 90s, CAD as we know it was born.


Today, CAD software is used heavily within various architecture, arts and engineering projects.

Compared to traditional technical sketching and manual drafting, the use of CAD design tools can have significant benefits for engineers and designers including:

  • Lower production costs for designs

  • Quicker project completion due to efficient workflow and design process

  • Changes can be made independent of other design details, without the need to completely re-do a sketch

  • Higher quality designs with documentation (such as angles, measurements, presets) built into the file

  • Clearer designs → better legibility and ease of interpretation by collaborators since handmade drawings are not as clear or detailed

  • Use of digital files can make collaborating with colleagues more simple

  • Software features can support generative design, solid modeling, and other technical functions.

Besides being a great tool for digital design, CAD is also used in 3D printing! As you can imagine, trying to tell a 3D printer what to print using a hand-drawn design would not be very effective, since scanners are not super accurate and the printer may misinterpret it and waste materials. CAD, on the other hand, creates files that 3D printers were designed to read. You can tell the printer how tall the object will be, the radius or area of any shapes in your design, or anything else you can think of when trying to translate a digital image into the real world.