I always admired people who could do those types of drawings. When I was designing woodworking and other projects for magazines, I had to deliver dimensioned drawings for them, including detail drawings. I had a small drafting table and a drafting machine to do those, but not the skills needed to do the types of drawings used in the actual magazine. So, I did either three view or isometric drawings, with enough detail drawings to illustrates some things. I was expected to work accurately to scale and include dimensions extensively. Then, the graphic artist at the magazine turned my crude drawings into the cutaway or exploded views used in the actual published article. I was always envious of the pros.
I got to talk to one of the magazine's illustrators a couple of times. I apologized for my clumsy efforts, but was told that what I was delivering was better than they usually got and I shouldn't worry about it.
There were a lot of expectations for the guys who designed and wrote up those projects. Not only did you have to produce the drawings, but also professional quality step-by-step photos and often the feature photo of the finished product. You also had to write clear instructions for reproducing whatever it was. Only when something was going on the cover did they budget for a professional photographer. The pay was OK, but the skills required to do the job went way beyond just being able to design and make stuff. I loved it for about 12 years, but moved on after that to something a little less intense.