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.
I got a bit more time today, so maybe today evening (German time), elsewise I'll have to skip Friday, so likely Saturday afternoon.
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.
> It does make me wonder about the algorithm
IIRC he uses a pretty simple algorithm. I remember him discussing the gating mechanism and how he had it follow a cycloid. I think there's a lot of opportunities for others to optimize the algorithms and he is focused on the physical engineering side. I'd love to see him collaborating with someone who does more reinforcement leaning. I also think it's very impressive what he achieves with such simplified algorithms.If I'm misremembering or missed something please correct me. I'm out now but I'll try to find the video of him talking about gating when I'm back if someone hasn't already linked it.
Also, I love how YouTube has all these "small" creators doing extremely impressive stuff. It's a real shame the algorithms make discovery challenging. The beauty of something like YouTube is not about just getting something to watch, it's by being able to get access to any content. Search is always a difficult problem to solve but I'm afraid it's currently over optimizing for views rather than intent. Which, to be fair, is much harder to measure. But I say over optimized because frequently I can search the title with 90% accuracy and fail to find the video. Something minor like missing an "s" or something effectively non meaningful. It's extremely frustrating...
If I'm reading your comment accurately, you're mentioning the discovery algorithm, which is neither of these. I also got the video, but I was already subscribed (it was suggested to me when it was released). Yes, the discovery algorithm has some of these issues but I'm more understanding of that because it's a much harder problem.
Both have self inflicted problems and I think they can be more easily addressed:
Discovery over optimizes to recent views and can get stuck in certain genres[1]. There is also a strong preference to things average user enjoys which doesn't work well for those of us who are only slightly less schizophrenic than the algorithm itself. Too much exploitation, not enough exploration (I wish this was a setting I could adjust. My mood changes, how can I let the algorithm know?)
Search has two critical self inflicted problems.
1) after about 5 results it will suggest completely unrelated videos (looks like it hands off to the discovery feed). Sometimes I need page two... just fucking show me more...
2) the problem I mentioned previously, where it distrusts you prioritizing popular videos over a trivial spelling or grammatical error. Google search has this exact same problem.
[0] my dumbass didn't check which video was linked. It's this one where he discusses it. At 12:30 in the video
[1] this leads me to having tons of YouTube tabs open as I'm unsure if a video I'm interested in but don't have the current bandwidth for is never going to be shown to me again
But i don't like how aggressive it is with suggestion. If i search some random topic, my newsfeed will be flooded with all videos about that topic many days later. So sometime i have to use different profile just to not "contaminate" the algorithm.
0. High Precision Speed Reducer Using Rope: https://www.youtube.com/watch?v=MwIBTbumd1Q
1. Building a DIY Surgical Robot https://www.youtube.com/watch?v=d_8rHKrwr-Q
The advantage over gears is that overloads are distributed over much more material. You don't snap gear teeth. This is good for leg landing shocks.
[1] https://www.impact-fibers.com/info/unveiling-the-strength-ke...
Steel cables would work just as well if weight isn't a consideration, but I think Dyneema is likely to be more resistant to abrasion. However, heat produced by any significant dynamic friction will ruin it immediately, as I found to my sorrow. Kevlar is much more heat-resistant, and of course steel is more heat-resistant than Kevlar.
I'm quite fond of bowstring as a material for this sort of thing. It usually has other fibres mixed in with it so it's a little more bouncy than raw dyneema but that's minimised if you get thread that's intended for crossbows. It's usually waxed so there's some friction to it when you're manipulating it, and it's also easy to source.
Potential and active founders here should consider reaching out (i think a startup setting would suit him better than corporate research), though he’s obviously got his own stuff going on and a degree to finish!
CARA is a super cool project which is never going to kill anybody, but it's another piece of evidence that the cost of the technology for such weapons has decreased enormously.
That said, talking about the dread is going to get boring fast, because nearly every story on the HN front page is catapulting us toward that future.
What matters, given that it meets the minimal bar of weirdness to be potentially worthwhile, is whether it's correct. Which depends on what future combatants will do once weaponry actually is autonomous, not what Ukraine and Russia are doing with remotely-piloted FPV drones.
Burnia sends their million autonomous weapons to kill the million people they judge are most crucial to Hevonia's war effort, prioritizing Hevonia's political leadership and military officers.
Hevonia, meanwhile, sends their million autonomous weapons to destroy Burnia's autonomous weapons, when they can find them, but not to attack any humans.
Who wins the war?
I think Burnia does, because even if Hevonia's weapons are 99% effective, Hevonia's government has still lost its top ten thousand people, including all of their military officers, while Burnia has only lost half a billion dollars. That's going to make it impossible for Hevonia to keep fighting. And I think 50% effective is more likely.
You're talking about a whole bunch of targeted and intentional attacks in a literal warzone, the most lawless kind of place on the planet and you're complaining that they are hitting their intended military targets?
Meanwhile Gaza is boring to you, because Israel uses conventional bombs with humans in the loop, even though the collateral damage matches your prediction today.
I'm saying that the events we're seeing in the Ukrainian war are convincing evidence that the nature of war has changed, and the implications of that change for human society are disquieting.
For two million years, people have often resolved conflicts by warfare. But that warfare, though it has never ended completely, has always been localized, which meant that most places most of the time were peaceful.
This is the foundation of the system of international relations in which different states exercised monopolies of legitimate violence over geographical territories: by so doing, they could prevent warfare and provide security. This system has existed to one extent or another for thousands of years.
Warfare is no longer localized, so now the only place for anywhere to be peaceful will be for everywhere to be peaceful. It is no longer possible for states to provide security to the people within their borders. Consequently statehood itself has lost its meaning. The last time we saw such a change in the nature of warfare was twelve thousand years ago when the first states arose.
I have some corrections for you about other things that you did not understand either about my comment or about the wars we are commenting on.
It bears repeating that the planes blown up in Operation Spiderweb were not in a literal warzone, nor anywhere close to a literal warzone. Some of them were thousands of kilometers from the literal warzone, in a part of Russia that has China and Mongolia between it and Ukraine.
The Ukrainians reportedly did have humans in the loop for that attack in particular, and both the Ukrainians and the Russians are mostly using FPV drones rather than autonomous drones of any sort at this point, unless we count landmines as "autonomous drones". In https://www.youtube.com/watch?v=RmfNUM2CbbM Russian drone developer Sergey Tovkach specifically says that Starlink is the reason Ukrainian sea drones have established control of the Black Sea — Russia could build sea drones but does not have an equivalent to Starlink, so evidently both Ukraine and Russia are dependent on remote piloting for their sea drones. He also says Starlink's latency is too high for piloting quadcopters. (Evidently Operation Spiderweb used the Russian cellphone network.)
The Israeli attacks are also using precision-guided weaponry and (in some sense) AI, not conventional bombs, and they're killing lots of innocent people, but you're right that it's less worrisome to me, for three reasons:
- The total number of people they're killing is about an order of magnitude smaller, about 80,000 so far (out of a total of 2.1 million Gazans), versus roughly a million in the invasion of Ukraine. Many more civilians have been killed in Gaza, but both Russia and Ukraine practice conscription, so it's not as if the soldiers being killed are only or even mostly volunteers; they were civilians until being, in many cases, conscripted.
- The weapons Israel are using are mostly very expensive, which limits the number of people they can afford to kill with them. By contrast, the drones being mass-produced in both Ukraine and Russia cost only a few hundred dollars each, and each country is expected to produce about 3 million of them this year.
- The people Israel are killing are almost entirely in close geographical proximity to Israel. Gaza City is 80 km from Jerusalem. Beirut, the residence of many of the Hizbullah personnel that Israel killed with explosive charges in pagers (along with, in several cases, their children), is 230 km from Jerusalem.
Therefore, while Israel's war is clearly causing terrible suffering to millions of innocent people, and it could easily spiral into a Third World War, it does not represent the advent of a new, borderless mode of warfare in which the cost of untraceably killing a precision-targeted human anywhere in the world is similar to the cost of a small air conditioner or 20 kg of beef.
The developments we are seeing of the mode of war in the Ukrainian invasion do represent such a transition, and that is true regardless of how the conflict goes. But mostly it is not the Ukrainians and Russians who are responsible for the transition; it was an inevitable result of developments in batteries, motors, power electronics, and 3-D printing and (more broadly) digital fabrication.
What will the new equilibrium look like, now that statehood is effectively meaningless? Well, it might be better or it might be worse, but not many people currently alive will live long enough to find out.
I'm surprised that Ukraine isn't DIYing full-on solid motor cluster SAMs and armor piercing ATGMs. I thought those kinds of devices were something just about any sufficiently developed country can do in days to weeks should such national emergency arises and all bets were off, except nations in peacetime has moral obligations to do no evil.
Also, I wonder how resistant this mechanism is to wear and fatigue.
Isn't having more decimal places the exact definition of precision (vs accuracy)?
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"
It's also interesting because competing actuators with strain-wave, cycloidal, or planetary gearboxes will state exactly what the ratio is. The actual gear teeth may not be spaced out perfectly around the circumference, but the number of teeth is an integer with an infinite number of zeros.
He could also go with narrower rope, and spread the load over more windings, which would give him more throw.
That's why pro crews don't use gears and ropes. At high impulses deformations and elasticity throw the kinematics off what's actually happening. Modeling the deformations and the elasticity is a computational no no. Instead what you see is the motors right on the joints.
At least that was the case last time I had a look at robotics.
the motors were so sloppy the company wasted a ton of money [0] having me write heuristics to tackle the errors they accumulated over several hours.
one of his whole points is that by using dyneema (rope), there's almost no elasticity at all in the capstans.
[0] relative to the cost of better motors
The answer here, as with so many things in robotics, is: It Depends.
UR10e robot arm that can lift a 4kg object with a reach of 1m and has sub-1mm repeatability? Strain wave gears in the base and shoulder joints, 100:1 ratio.
MIT Mini Cheetah robot dog that can do backflips? 6:1 planetary gearbox.
Shadow Hand with 20 degrees of freedom? Tendon driven, with the 20 motors in the forearm to keep the fingers slim.
Little dinky Huggingface SO-101? Servo motors, integrating 1:345 gearing with a series of 6 tiny brass gears.
Mid-price CNC milling machine, if you call that a robot? Really long ballscrews, driven by stepper motors.
>Mid-price CNC milling machine
A ball-screw is mostly decorative on small machines... =3
Back-drivability is the enemy of precision, so many robotic applications can do without it.
The old "fast, cheap, or good... choose any two joke is mostly still true. =3
You’re right that it has a freedrive mode, and force control modes. But it’s a rigid, low-backlash robot with the compliance achieved in software afterwards.
Expensive, naturally, but none of the problems that come with things like series elastic actuators.
I think the X-Carve 3-axis wood carver uses stepper motors with belts of all things. The Shapeoko Pro is leadscrews and stepper motors. Wazers, I believe, are belt-and-servo driven. And a lot of 'CNC conversion kits' you can order online use stepper motors. Plus of course laser cutters have really low torque requirements, so they've got a lot of design freedom.
Arguably those are "cheap" rather than "mid price" it just felt weird to declare a $4000 machine to be "cheap"
Note that belts were continued through the Shapeoko 3 (I got a machine as a "thank you"), though the Z-axis got a leadscrew in the Z-Plus upgrade, then the Pro (since, I got a job with the company and got an XXL as part of my employment), then the 4 (the original Pro is referred to as a 4 Pro sometimes), and it is only with the 5 pro that ball screws were switched to for all axes (and I now have a 5 Pro).
For an example of what a belt-drive CNC can do see:
https://community.carbide3d.com/t/hardcore-aluminum-milling-...
Sure. Yet evolution has achieved astonishing kinematics with all manner of deformation and elasticity inherent to the materials, and also constantly changing physical properties, using low resolution data. We cannot build permanently lash free mechanical devices at reasonable cost and reasonable size/weight. Eventually, the answer must be pervasive real-time compensation throughout the kinematic model.
> Modeling the deformations and the elasticity is a computational no no.
Why? Nervous systems do this. That's why you can change your shoes and still walk upright.
That sounds like “It’s not wrong, we just don’t do it”. There are some amazing examples of imprecise drive systems compensated for by excellent control systems all over the world, for millions of years.
He actually discussed this in an earlier video for his initial tests on the capstan drive. He ended up testing the rope he used for around 358 hours (two weeks) on continuous use in the drive itself with very low backlash
"CARA (Capstans Are Really Awesome) is my latest quadrupedal robot, following ZEUS, ARES, and TOPS. Built over the course of a year, CARA is easily my most dynamic and well-designed quadruped yet."
But for a lot of tech/engineering channels, it'd be immensely difficult to make the same salary as you could working at a FAANG or the like. (I'm making about half what I made when I had a W-2, but it's enough).
The former has a rather large non-pecuniary component of total compensation.
Much better for someone to fund a startup run by him.
Hire him and put him in R&D in some robotics company.
I was a professor for a long time. My observation was that often a top researcher was also a top teacher and even a top administrator. There are exceptions of course. But if someone is smart and effective at using their attention, those skills transfer to many things.
It’s a pain in the ass when allocating university roles. I want that person to do EVERYTHING ‘cos they always deliver.
On top of studying engineering at uni, his "side-gig" is being creative, empathetic, and fantastic at communication - and your prime recommendation is to "hire" him to be a specialist hidden away in the back office? Which interwebz forum are you on?
EDIT: My last question is clearly an echo-chamber statement. But that doesn't subtract from the fact that, yeah, should he found a business, yes, he'll deal with certain "BS". That is the weight we'll all carry. But he's quite likely capable of moving civilization forwards, so... :shrug:
The implications of the tools we now make available for use in our own personal workshops are still being discovered, and will be for some time.
Or if you're already all over the basics, figure out what kind of stuff you want to build and then try and build it. :)
https://www.youtube.com/watch?v=u4Jh1daCl60
https://github.com/evildmp/BrachioGraph
Sample Supply List for $80 budget:
Pi Zero with header $20: https://www.adafruit.com/product/6008
Power supply $9: https://www.adafruit.com/product/1995
SD Card $10: https://www.adafruit.com/product/1294
Three hobby servos $18: https://www.adafruit.com/product/169
Breadboard wires $5: https://www.adafruit.com/product/153
Breadboard $5: https://www.adafruit.com/product/64
Glue, popsicle sticks, pen and paper $10
I feel this deeply, also this whole video is quality content.
Time to raise my own bar.
Update: Ah, weird, if I watch the non-embedded one on youtube it is the original in English with normal sound. It's the one embedded on his web site which has AI translation to German.
As an end user, there's nothing you can do to prevent from seeing them. But you can change the audio track to the original while the video is playing.
WHAT?!? It a time when there is a growing animus towards AI generated content, for many content creators this would be tantamount to slander
Anyway good engineering requires extensive testing over many hours of movements.
He actually discussed this in an earlier video for his initial tests on the capstan drive. He ended up testing the rope he used for around 358 hours (two weeks) on continuous use in the drive itself with very low backlash
It definitely gives off Elysium (film) vibes.
Geordi LaForge reminds me of Aaed.
The platform in the video and the robot dogs from Boston Dynamics are ideal for tasks where they are only limited by their own weight and the amount of computing power required to navigate, such as exploration.
I suppose that's why we mostly see autonomous delivery robots on wheels.
Or maybe I am being too pessimistic about other platforms...
Breaking Taps on YouTube did a really awesome video on a somewhat similar mechanism (I'm no mechanical engineer haha, it was new to me!), rolling contact joints. I love the idea of using string/ropes. Worth checking out as well if this kind of stuff interests you! https://www.youtube.com/watch?v=TQiLLcumqDw
hakonjdjohnsen•1d ago
PaulDavisThe1st•1d ago
hakonjdjohnsen•19h ago
When I came across this amazing project and wanted to share it to HN, I was debating whether to post the youtube link or the project page. I decided to post the project page and mention the youtube link in the description for those who prefer video, but somehow that description got posted as a comment instead (not sure how that happened?). Anyway as you said the video is embedded in the project page so it wasn't really necessary