I had never seen a rope use a robot dog before so I clicked immediately. It wasn't what I expected from the headline, but very cool nonetheless.
CARA – High precision robot dog using rope
171–180 of 188 posts
Re: CARA – High precision robot dog using rope
#172Earlier quoted context omitted.
Dynema makes a huge difference, a true game changer in many ways. I came across it rigging sailboats where is started out replacing ropes and now replaces steel cables as well. Spectra is another brand with different, equally amazing properties.
Spectra and Dyneema are both UHMWPE. They're different brand names (from Honeywell and DSM respectively) but chemically and mechanically the same, possibly with some small and insignificant differences due to manufacturing processes.
That’s an answer straight from an LLM methinks and not reflective of actual experience. Read up on real world tests for the practical differences. They are very similar but far from “the same”.
Re: CARA – High precision robot dog using rope
#173I'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.
These drives sound amazing, so why are they not used everywhere? What are the disadvantages?
Re: CARA – High precision robot dog using rope
#174Re: CARA – High precision robot dog using rope
#175Earlier quoted context omitted.
That would be a terrible path for someone with this extreme level of demonstrated talent, motivation, and follow-through. Much better for someone to fund a startup run by him.
Why would you put someone with clear talent at building stuff in charge of running a startup? He'll get bogged down in lawyers, day to day operations and growth strategies. Hire him and put him in R&D in some robotics company.
... what tf?
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:
Re: CARA – High precision robot dog using rope
#176Earlier quoted context omitted.
"back in the day", we used capstans to drive film (movie) rolls around the scanning aparatus. Both high speed and precise without backlash. Great stuff. Somehow I always thought maybe lack of high torque is the issue more people aren't using them or wear and tear.. but, apparently not?
Dynema makes a huge difference, a true game changer in many ways. I came across it rigging sailboats where is started out replacing ropes and now replaces steel cables as well. Spectra is another brand with different, equally amazing properties.
Interesting you've mentioned sailboats. I've encountered dyneema for the first time in spearfishing!
Re: CARA – High precision robot dog using rope
#177Oh man, that first capstan drive video was awesome and I kept wondering what he was going to do with it. A lot, apparently! This is so cool.
Edit: And yes of course, in hindsight, you don't build a leg unless you're planning to build a thing with legs.
Re: CARA – High precision robot dog using rope
#178Earlier quoted context omitted.
He actually used steel cables for his initial prototypes, but steel cables have a problem with rolling fatigue that actually gets worse the larger the diameter...so if a tiny steel cable is not strong enough, you might actually have to change the gear dimensions (and therefore ratios) in order to not fatigue them.
Right. Steel cables have to be oiled internally if flexed frequently. This was a major cause of cable failure in gym exercise machines for decades. Newer exercise machines tend to use synthetic flat straps over pulleys.
The Sandia paper also claimed that steel cables need a larger pulley radius.
Re: CARA – High precision robot dog using rope
#179Earlier quoted context omitted.
Well, suppose you have two countries at war, say, Burnia and Hevonia. They each produce a million autonomous weapons. 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…
It's the same question as when one opponent is ready to nuke enemy cities while the other is not. In theory everything turns out the same way you postulate. In practice cost of winning the war in this manner might be higher then the cost of losing localized, limited conflict.
That's why there's never been a war between two nuclear-armed countries: everybody is shitting in their pants because of exactly that logic. Presumably we'll find out when the PRC invades Taiwan.
However, if that doesn't end up with a radioactive wasteland, we'll probably find out shortly afterwards what happens when every two-bit drug cartel or extortion mafia can cheaply assassinate anyone, anywhere in the world, with an ambush drone.
Re: CARA – High precision robot dog using rope
#180Earlier quoted context omitted.
It's the same question as when one opponent is ready to nuke enemy cities while the other is not. In theory everything turns out the same way you postulate. In practice cost of winning the war in this manner might be higher then the cost of losing localized, limited conflict.
That's why there's never been a war between two nuclear-armed countries: everybody is shitting in their pants because of exactly that logic. Presumably we'll find out when the PRC invades Taiwan. However, if that doesn't end up with a radioactive wasteland, we'll probably find out shortly afterwards what happens when every two-bit drug cartel or extortion mafia can cheaply assassinate anyone, anywhere in the world, w…
> However, if that doesn't end up with a radioactive wasteland, we'll probably find out shortly afterwards what happens when every two-bit drug cartel or extortion mafia can cheaply assassinate anyone, anywhere in the world, with an ambush drone.
I wonder what's stopping them right now. They used drones to smuggle drugs already.