How a Manual Transmission Works
A demonstration of the basic principle behind a constant-mesh manual transmission. The animation is loosely based on Toyota's 5-speed R150, and the 3D model it is created from is available on Thingiverse at https://www.thingiverse.com/thing:3776077
I hope that the video is helpful and instructive for some.
(Synchronizers are not covered here - for the sake of brevity and clarity)