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CARA – High precision robot dog using rope

aaedmusa.com

21–30 of 188 posts

Re: CARA – High precision robot dog using rope

#23

Why spend so much effort to achieve an "exact" gear ratio? Having more zeros does not equal to being more "precise". Also, I wonder how resistant this mechanism is to wear and fatigue.

That was confusing part of this video . May be there are some limitation on the tools he uses to tune

I don't think the number of the gear ratio really matters, what matters is that you know what it actually is (since every IK calc depends on said ratio); 8:1 is probably arbitrary and/or looks nice & might simplify some stuff.

Re: CARA – High precision robot dog using rope

#26
post #23

Earlier quoted context omitted.

That was confusing part of this video . May be there are some limitation on the tools he uses to tune

I don't think the number of the gear ratio really matters, what matters is that you know what it actually is (since every IK calc depends on said ratio); 8:1 is probably arbitrary and/or looks nice & might simplify some stuff.

It might be a lot easier to check the ratio "by hand" (by counting rotations etc) if it's numerically simple. (IIRC in some earlier videos he noticed that the pulley size ratio wasn't producing the expected movement ratio, because they were built as an obvious 8:1 or 10:1 or something, and didn't match - which led to him figuring out the subtleties of the design - I can easily imagine wanting to preserve that aspect just for debugging, at that point, even if you now have correct math.)

Re: CARA – High precision robot dog using rope

#27

Why spend so much effort to achieve an "exact" gear ratio? Having more zeros does not equal to being more "precise". Also, I wonder how resistant this mechanism is to wear and fatigue.

Well, it probably wasn't that much effort. When you're 3D printing you're going to end up printing everything 2-3 times anyway, so why not dial in the ratio while you're at it?

And you can't really declare your design is "high precision" and present yourself as someone others should take transmission design advice from if you aimed for a gear ratio of 8 and achieved "somewhere around 7.9 to 8.2"

Re: CARA – High precision robot dog using rope

#28
post #4

[flagged]

Definitely.

It's intellectually exciting.

On the flip side, capitalistic / private / special interests both controlling the progress and having the most ability to utilize it to further centralize power and wealth is deeply concerning. We can already see more controversial figures involved in AI using it to spread their personal viewpoints.

It feels really easy to see how our jobs/labor and therefore our capital and therefore our value in the modern system are being directly attacked by these capabilities and deeply concerning to imagine how further centralization of power could be good for the masses.

Re: CARA – High precision robot dog using rope

#29

I've watched and re-watched Aaed's videos on the capstan drive, it's great stuff. High speed, high torque, compliance, effectively no backlash. It's fascinating to watch a legit engineering mind at work.

He's easily one of my favorite content creators. Ofc, there are much better engineers, domain experts or more entertaining people on youtube, but he strikes a very enjoyable balance.

I wanted to start writing a list of other tech related, pop-sci and industrial-design Youtubers I kinda enjoy, but noticed just how many channels I'm subscribed to... If there's any interest, I'll drop it, just tell me. Meanwhile I have some filtering and sorting to do.

Re: CARA – High precision robot dog using rope

#30

I've watched and re-watched Aaed's videos on the capstan drive, it's great stuff. High speed, high torque, compliance, effectively no backlash. It's fascinating to watch a legit engineering mind at work.

I recently found his videos also. It's one of those things that gets my mind bubbling with ideas for things I want to make, never enough time to do them all though (and this breadboard beside me is asking for attention)

It does make me wonder about the algorithm, Quite a lot of things I find on Youtube turn up on HN a week or two later. I'm not sure if this is an indicator of the effectiveness or failure of the algorithm. It is definitely succeeding in finding videos popular with some people and showing it to more who might share that interest. The question is, are the things I (and consequently many others of similar interests) see the best of all there is, or a subset of the excellent videos out there that happen to get noticed.

I sometimes find channels that are years old with a goldmine of good information. That suggests that there is more good stuff out there than what I see. Were they just unlucky that I didn't see them before? Am I lucky to be seeing them now? It also might be that it is not luck but the algorithm has arbitrarily decided that the video has some special factor that requires promotion or that I have passed some arbitrary threshold of perceived character development that makes me supposedly now interested in such things.

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