Reference:
https://www.91suke.com/s/fe26a62e
http://school.blcwc.edu.hk/dt/P/Notes/Lesson6/Topic6_Note.pdf
https://resources.hkedcity.net/res_files/201102/20110208104412_333659.pdf
https://grabcad.com/library/animated-round-rack-and-pinion-gear-1
