It took me a few days to get my system down, especially for the screw tip. It took me a while to figure out a way to inference consistently the profile progressing on the spiral. Of course, the first time I completed the tip, I saw that I had reversed the thread direction. On my second attempt I lost the tip in the processing of scaling up 1000 x’s. Exactly when I clicked on show errors after using Inspector, the screw tip disappeared. This last time, I just left it small and didn’t scale at all. I was mainly using guidelines from the protractor tool, the line tool, and checking as I went with Inspector. Most of the time it would remain solid, once I got my inferencing figured out. Next, I’ll start working on different heads and lengths. I will attempt to line up on the red axis to meet the threads.
I hope you are doing this as a learning and technique exercise and not because you intend to include such screws in real models. It is very rarely necessary to include such small details in a model. All that anyone building whatever will be fastened with these needs to know is the size of screw and where to drill the pilot hole. Including detailed screw components will just bloat the size of your model beyond what is really needed! If you want, you could use a low-poly notional model of the screw for prettiness, but even that isn’t really essential.
That’s pretty cool. The model on which I’m working has a ton of bolt threads and initially I looked at accurately representing them, but it was so tricky I said the heck with it and cheated with “accordion” (non helical) fake threads. It’s not like anybody can really tell the difference.