5 HN users recommended this explainer5 months2018–2026score 5.5
Years with an HN recommendation, 2007–2026
It is held up as a model of clear, well-paced educational film and of the old-era instructional style.
A 1936 Chevrolet-sponsored film that explains how a car transmission works by treating gears as spinning levers. It uses physical models to make the mechanism clear.
“The editing, pacing, and style were better.” (HN, 2019)
The editing, pacing, and style were better. Educational videos today tend to go to one of two extremes. Either they're a talking head with PowerPoint, like most of the "massively online" courses. Or they have way too many jump cuts, like theatrical movies which want your attention, not your understanding. There's also an annoying tendency to have distracting music and irrelevant graphics during narration. Here's an old Jam Handy film, "Spinning Levers", on how a transmission works.[1] There's a whole series of these Chevrolet films on the Internet Archive, covering major vehicle systems. Things to note: - There's a narrator and a demonstrator. We never see the narrator, and the demonstrator never talks. So the viewer can focus. - The demo models of parts are really good. They start with a simple version and add features until a full transmission has been built up. - There's some simple animation. Animation is used to point out how power flows through the gears. This is much clearer than someone using a pointer. - The editing and narration are very well synchronized. - There's an entertaining part at the beginning and end, so you don't feel like they're beating you over the head with the boring stuff. [1] [this video]
Model of good educational film editing, pacing and demonstration.
Lately, because of a car situation, I've been watching car mechanic videos online. There's some old videos, like 1937 old, made by Chevrolet, that explain really well how different mechanics of a car work. One explains a transmission starting from levers[1], how they work to give mechanical advantage, and how gears are basically spinning levers. I ended up feeling like I could make a basic transmission if I only knew how to make metal pieces in the shapes I want. From there I've been looking at people disassembling automatic transmission and explaining the different parts. I gotta say, learning how these machines work mechanical advantage to something so convenient has really raised my interest in physics and mechanical engineering. I don't remember simple machines[2] being something so interesting back in physics class. I don't blame the teacher, 'cause she was always enthusiastic about physics. I wonder why this is more interesting now than then. It's probably just that, now that I'm older, I can understand complex applications of those fundamentals being taught at school. [1] [this video] [2] [link]
Explains transmissions starting from levers and gears as spinning levers.
A couple of other examples: an old US Army training video on the workings of various categories of firearms [0], and an old video on how transmissions work [1]. Both make great use of physical models of the mechanisms. [0] [link] [1] [this video]
Old video using physical models to show how transmissions work.
This old training video is great too, it also mentions the idea touched upon in the article that gear teeth are levers: Spinning Levers - How A Transmission Works (1936) [this video]
Training video that also treats gear teeth as levers.
Similar videos about cars: Chevrolet Suspension (1938): [link] How Differential Steering Works (1937): [link] How A Transmission Works (1936): [this video] And as a bonus, an explanation about transistors from 1953: [link]
I get a similar feeling looking at instructional videos from that era[0][1], or reading books like Stick and Rudder[2][3], or even the simple brilliance of the visual design of the London Underground[4]. There's a pervasive sense that despite the reams of progress that has been made in the science of human factors, simple straightforwardness is becoming an endangered species. [0] [this video] [1] [link] [2] [link] [3] [link] [4] [link]
Example of straightforward instructional videos from that era.
I think this “awesome”, “amazing”, “super exciting” phase came much later than the moon walking era. Remember it’s been over 50 years since humans walked on the moon. Much has changed. See these old videos, where people talk in a straightforward way: Car transmission [this video] How to dial your phone [link] The dial comes to town [link] Now go watch that Apple video again and you’ll see what I’m talking about.
Example of plain, straightforward explanation from an older era.
Video list and Hacker News comment labels from HackerTube (prompted by @karpathy), released under ODC-By 1.0, built on the open-index/hacker-news archive. Hacker News data is provided by Y Combinator; comments remain the work of their authors. Video titles, channel names and thumbnails belong to their creators and are shown via YouTube. HackerTube Watch is an unofficial edition. Data export of 2026-10-31.
9 Hacker News comments
From the HN archive; up to 20 kept per video, favoring different commenters. Recommendations first.
Read more
Read more
Citations, criticism and jokes