Although sketching by hand has been used for quite a long time by engineers to describe objects, a new alternative has recently been popping up: Computer Aided Design. These programs, such as SolidWorks, solve the problem that hand sketching also solves, except it does it much more quickly and efficient. After the model is designed in 3D in SolidWorks, it’s only a click or two away from a fully detailed orthographic or isometric drawing.
Hand sketching may be useful if there are no computers where you need a quick design, but we live in the twenty-first century. 3D sketching is quicker, stored more securely, and less prone to human errors.
It’s not to say that hand sketching is a bad thing to learn. Sketching gives you a better understanding of visualizing shapes in three dimensions. I guess it’s analogous to learning arithmetic versus using a calculator. Everyone who uses math should know basic arithmetic, but there comes a point where the use of the calculator is a powerful tool that lets you solve complex problems as easily as before. After a person is fluent in visualizing and recreating shapes in 3D, using a tool like SolidWorks isn’t in any way harmful. It saves time and reduces errors.