Originally published at: https://boingboing.net/2019/05/06/so-this-is-why-train-wheels-ar.html
…
5 Likes
I prefer Feynman’s explanation.
32 Likes
Maybe it would be better to link to the original video:
17 Likes
I am reminded of the Whee-lo, the wheel of which spins on conical magnetic hubs.
9 Likes
Once you go conical, you never go back.
12 Likes
Very good explanation… I never thought before
6 Likes
We’re so screwed if we ever have to recreate the world’s knowledgebase from scratch.
13 Likes
“Cone-Wheel, what is best in life?”
“To taper from the inside to the outside, to have a rigid axle, and to hear the lamentations of the flange.”
31 Likes
Axle. It’s spelled axle.
10 Likes
14 Likes
The explanation misses one of the key aspects. The conical wheels allow/force the the set to move to the outside to so that the outside wheel becomes effectively larger in diameter, thus allowing it to take the longer path without skidding, while spinning at the same rpm. Added benefit is that it naturally banks the train carriage to the inside a little (although high-speed curves are banked as well).
17 Likes
They have the props. They have the story. But the combination of the music, and the minimalist captions that disappear before the action makes this video more confusing than it needs to be. I had to watch the video several times before I figured out what was going on.
3 Likes
Lovely. His joy is infectious in describing how clever this mechanism is.
7 Likes
You can build your own demonstration model with two styrofoam cups.
1 Like
Admittedly, I already knew the answer. But I found the minimalist presentation to be an asset. Seeing it work is better than hearing it described how it should work. (Apologies to Feynman, who could make a story about putting coins in a parking meter into something fascinating.)
3 Likes
Indeed, the initial video is missing any kind of explanation at all. A viewer is left to intuit the answer, but I bet the vast majority of viewers who didn’t know how this worked to begin with probably watched this, said “ah ha!”, and left with no better understanding.
Feynman’s explanation at top is how I originally learned it.
1 Like
TLDR-No differentials.
1 Like
This post seems to be bleeding over into my universe where the train wheels are cylindrical with a flange.
3 Likes
