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.
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.
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
No disagreement, but does the comment meaningfully contribute to the discussion about this particular project?
[0] https://screenrant.com/matrix-timeline-year-future-when-sett...
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.
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.
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.
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.
"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.
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 $10I feel this deeply, also this whole video is quality content.
hakonjdjohnsen•7h ago
PaulDavisThe1st•6h ago