Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

CARA – High precision robot dog using rope

aaedmusa.com

Post reply on HN
Print view View original

41–50 of 188 posts

Re: CARA – High precision robot dog using rope

#41

Post by Retr0id »

Paddywack wrote: post #35
taneq wrote: post #32

Earlier quoted context omitted.

Arduinos and hobby servos. No, neither of them are "industrial grade" and yeah, you'll reach their limits pretty quickly, but building a physical thing that does stuff is (in my experience) a huge motivator. 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. :)

Can you recommend where to find beginners projects that “do stuff”.

Just like the article, there's a huge amount of hobbyist-accessible projects on youtube, you can click around the recommended videos.

Re: CARA – High precision robot dog using rope

#42

Post by adolph »

heap_perms wrote: post #22

Fascinating! I want to get into this type of stuff. But I have no idea where to start, I just have just a CS degree and 3 years experience as a developer.

I recommend a Brachiograph build. It will introduce you to some fundamentals of PWM and inverse kinematics. It is well documented but not cookie-cutter. Using a Raspberry Pi will give you more direct access to running the servos than the microcontroller experience. All the parts are infinitely reusable afterward if you don't want to keep it around.

https://www.youtube.com/watch?v=u4Jh1daCl60

https://www.brachiograph.art/

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

Re: CARA – High precision robot dog using rope

#43

Post by busymom0 »

dvt wrote: post #21
andrewstuart wrote: post #20

Earlier quoted context omitted.

He might be perfectly happy doing projects and YouTube.

Likely makes more money, too!

His current Patreon has 57 paid members. Unless he has another revenue stream, I think he'd need more paid members.

Re: CARA – High precision robot dog using rope

#44

Post by adolph »

btbuildem wrote: post #3

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 haven't watched the one about the dog, but the one with the initial explication of capstan drives [0] was excellent. I've been dreaming about it for the last year, especially since about the same time another person started working with the da Vinci robot actuators which use cables to generate find motion.

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

Re: CARA – High precision robot dog using rope

#45

Post by sitkack »

geerlingguy wrote: post #39
dvt wrote: post #21

Earlier quoted context omitted.

Likely makes more money, too!

For many, no; taking on lots of sponsorships, you can make a good amount of money (especially the ones where you agree to do X posts across Y social media accounts for Z period of time, essentially being fully sponsored across a large swath of life). 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…

You just need to start selling supplements, anti-aging creams and time shares.

Re: CARA – High precision robot dog using rope

#46

Post by abtinf »

geerlingguy wrote: post #39
dvt wrote: post #21

Earlier quoted context omitted.

Likely makes more money, too!

For many, no; taking on lots of sponsorships, you can make a good amount of money (especially the ones where you agree to do X posts across Y social media accounts for Z period of time, essentially being fully sponsored across a large swath of life). 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…

Do fun projects of your choosing vs the grind of corporate life.

The former has a rather large non-pecuniary component of total compensation.

Re: CARA – High precision robot dog using rope

#47

Post by sitkack »

Paddywack wrote: post #35
taneq wrote: post #32

Earlier quoted context omitted.

Arduinos and hobby servos. No, neither of them are "industrial grade" and yeah, you'll reach their limits pretty quickly, but building a physical thing that does stuff is (in my experience) a huge motivator. 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. :)

Can you recommend where to find beginners projects that “do stuff”.

Grab a servo and start playing with it.

Re: CARA – High precision robot dog using rope

#48

Post by abtinf »

AIorNot wrote: post #8

Amazing presentation! - somebody hire this kid asap https://www.aaedmusa.com/

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.

Re: CARA – High precision robot dog using rope

#49

Post by michaelt »

throwawayffffas wrote: post #37
fusionadvocate wrote: post #7

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.

I think it's about kinematics, the more precise your gears the better the model fits the real world. 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 lo…

> That's why pro crews don't use gears and ropes. [...] Instead what you see is the motors right on the joints.

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.

Post reply on HN