This is a procedure how to draw a 2D outline of a torus, with a section by the axial plane, or with a coil that wraps the torus.
It's not a detailed tutorial but any experienced inkscape user would be able to figure out how it works.
It uses the orthographic projection, FYI.
https://drive.google.com/file/d/0B56fvn-znCEVdkd2OExldGlLVU0/view?usp=sharing