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by wherkewitz 4100 days ago
Also: Everyone should know this. There are still huge issues that need to be figured out before this becomes a commercial product. The 7% figure is bound to change depending on the speed you walk at (diff. speeds will likely require springs with diff. stiffnesses for optimal efficiency). Both Steve and Greg talked about future incarnations that could switch between multiple springs.

...and I didn't write that headline, or the dek (the thing under the head)
4 comments
bostonpete 4099 days ago
> Also: Everyone should know this.

Hm, OK...then why didn't you include that info in the article?

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semi-extrinsic 4099 days ago
Because that wouldn't fit the bill of unbridled techno-optimism that is mandatory in (particularly online) popsci/poptech reporting.

Sadly it's also widespread in the scientific literature, as "publish or perish" meets "won't print methods/results that are not said to be awesome".

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kbenson 4099 days ago
I think the dek is entirely appropriate. I would call this hacking walking, in the "examine, understand, circumvent" definition of hacking.
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maxerickson 4100 days ago
Did you get a sense of whether it required tuning to the user? It seems like the ratchet disengaging at the right moment would be quite important to making it comfortable to use.
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wherkewitz 4100 days ago
Well, two thoughts:

One.) At a set, low speed we all walk pretty much the same - at least when it comes to the movements the ratchet was picking up.

Two.) Might be interesting to note that they had a pretty small sample size (n=9), and some people were getting more a benefit than others. I think one participant was up to like 10%.

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araes 4100 days ago
To do this in full production mode, I would think you would probably make it user tunable.

As the article says, most of it is fairly simple. Just a spring for a cable and a ratchet that moves with the motion of your foot (kind of auto tuned), and grabs the spring.

If the spring was remotely tensible, you could probably just walk and adjust it until it felt best.

You could probably also do that at various speeds and then create a smooth mapping of ensuing parameters for various gaits.

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maxerickson 4100 days ago
Yes, I think it has to either be tunable or self adjusting. If the ratchet releases early, you are just carrying it around. If the ratchet releases late, I expect it will result in uncomfortable tugging.

So my question is more about the behavior of the implementation, not about the design space for it.

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ridgeguy 4099 days ago
Has this system been committed to a modeling package (like COMSOL, for example) so it could be rapidly optimized for particular use cases?
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