There is a very good video from 1937 by Jam Handy. It explains why we need differential gears and how they work.
I think the video is a masterpiece of an explanation. I recommend you watch it, not because understanding differentials is essential (though that doesn't hurt), but because the video can teach you a lot about how to explain something properly.
Here are some techniques the video uses (non-exhaustive):
- Start with giving the context of why the thing that is being explained is important, e.g. by describing a concrete problem to which the thing to be explained is the solution.
- Use visual explanations. Specifically, demonstrate the mechanism to be explained in action.
- Start to explain a simple toy model and then add layers of complexity until you arrive at the real deal.
I think I have never seen an explanation, that by its end has annihilated the possibility of misunderstanding so effectively, and I really like how smooth the transition is from background story to technical explanation. There is no jarring break.
This was great.
Tangentially, this post reminded me of this GPS explainer which I also thought was excellent as explanation.