Watch the video where I demonstrate how to draw light and dark ovals of different sizes as relaxed as possible.
Recording: De Foto Firma
Exercise: Try to imitate the exercise from the video. Move your arm as relaxed as possible, without bending your wrist or squeezing your pencil. Start the movement in the air before you hit the paper. Let your hand gently glide over the paper while drawing. Try it both clockwise and and counterclockwise.
Exercise 2: While rotating flat ovals, move up or down on your paper. Let your hand gently slide over the paper on the side of your little finger and keep your wrist and fingers relaxed. Try to keep the ovals the same width. It now becomes a so-called helix.
In a tornado, that helix becomes wider towards the top and sometimes changes direction.
Exercise 3: Draw one or more tornadoes. Try small and big ones. Draw your tornadoes in one line, so without letting go of the paper in between! This way your drawing hand becomes increasingly flexible. If you like it, you can make up things that are thrown into the air by the whirlwind. Hopefully everything lands safely on the ground again.
Of course, real screw threads can’t be drawn so casually; the spirally connected ovals must all be drawn equally diagonally and be exactly the same width everywhere. With two vertical assisting lines you ensure that the thread is the same width everywhere. If you draw everything lightly in the beginning, you can then make the thread more real with some light-dark contrast and shadows.
Screw threads