Simple toy joint sketches

I had some interest in how the movement of limbs work on toys. looking into some stuff I found a a small 3D printable elephant which I really liked the look of. Because I don't have a 3D printer and the files didn't explain very well as to how the legs of the elephant works, I decided to sketch out some quick drawings of how I would make the joints of the elephant work.

I will be expanding with more research into different joints used in engineering, toys and even some basic human joint. The reason for this is because I can use it in any moving part of my final product of my FMP.