If you’re interested in how to draw believable robots and machinery I taught a class that’s available through svslearn.com.
This isn’t a tutorial outlining a mech recipe, this class is a map showing the terrain allowing you to navigate your own design. I go deep into the thought process of design, demonstrate it, and even do draw overs of a few class member’s work.
When you order the class you’ll get a streaming or download option that you can watch any time. It also comes with a pdf of my lecture notes, and a workbook with a bunch of drawing exercises.