Grid Diagram for knot (example)
GIMP 2 (free photo program)
https://youtu.be/8PsHBYsJi98
Gimp tutorial for beginners.
https://youtu.be/pmLNsi7befw
Example of three-axis drawings.
I made them in Gimp2.
I use the tiny Raspberry Pi, ?30 credit card sized computer and GIMP runs on it wonderfully. It is like having Photoshop and Illustrator rolled into one - yet it is Freeware.
The only challenge is learning how to use it - but there are a load of Youtube tutorials, so well worth the effort.
Derek