[HN Gopher] Hand: open-source Robot Hand
___________________________________________________________________
Hand: open-source Robot Hand
Author : vineethy
Score : 319 points
Date : 2025-07-17 12:08 UTC (10 hours ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| ImPostingOnHN wrote:
| Looks like this product is called AmazingHand (and there are
| billions of "hand"s in the world), so the title might have some
| room for improvement as far as searchability goes.
| amelius wrote:
| Would it be possible to have tendons running through the arms, so
| the weight of the hand is reduced?
| stefanka wrote:
| Most tendons materials are elastic. That lead to create
| calibration problems and require proprioceptive sensors in the
| hand
| fusslo wrote:
| Huh, never thought of that
|
| I wonder if companies are experimenting with materials like
| UHMWPE for non-elastic, high strength-to-diameter tendons.
|
| I dont know if you'd have to weld the dyneema to the anchor
| points, though
| imtringued wrote:
| I think you're misunderstanding the essence of the problem.
| If you use tendons, you'll need a neural network in your
| control loop that can learn continuously so that it
| compensates rope stretch and changes in friction through
| wear and tear.
|
| A lot of problems in robotics reduce down to continual
| learning. Essentially all system identification tasks
| become obsolete the moment you have a self learning system
| and yet we have an AI industry preaching that AGI is around
| the corner without this "crutch".
| stefanka wrote:
| Not to mention that they easily break and are annoyingly
| tedious to be replaced (I had to assist often enough on
| such "surgeries" in our lab)
| amelius wrote:
| You could add encoder patterns to the tendons, like
| stripes. And then use something like a mouse-sensor to
| track them. This is still much lighter than servos.
|
| Another idea is to use an external camera or two and to
| track the fingers with a deep learning model. But this
| can become messy if other objects are in view. And it
| might also introduce more control delay in the feedback
| loop than a simple sensor.
| stefanka wrote:
| If space permits you should add absolute encoders in the
| joints. In a finger that's likely a challenge. In an arm,
| that's easy
| stefanka wrote:
| You don't necessarily need neural networks for that,
| there are more specialized function approximations that
| learn faster and enable life-long learning for
| kinematics/dynamics and extrapolate better than NN which
| are more general purpose.
| spauldo wrote:
| I would think pressure and angle sensors tied to a PID
| loop would suffice, but I'm not a roboticist.
| stefanka wrote:
| If you can get a feedback loop at the respective joint,
| then yes, this might be enough. In case of an arm (not
| this hand), you can often only observe the end of a
| chain, and then, that's more complex
| stefanka wrote:
| Roboy used dyneema tendons if I recall correctly. Fluidic
| actuators is another option. IMO, additional sensors and
| sensor fusion are necessary but this will raise the costs
| and demand to control software significantly. We are
| researching humanoid robots for quite some decades now and
| these problems are easily underestimated (similarly to
| autonomous driving). I doubt we'll see them in our houses
| very soon.
| fusionadvocate wrote:
| The issue is not that these problems are easily
| underestimated, but that the researchers are very
| proficient at repeating the same mistakes over and over
| again.
| stefanka wrote:
| Or both ...
| Symmetry wrote:
| In practice force sensing is more useful than proprioception
| in most cases, at least for grasping. Generally you won't the
| dimensions of an object you're attempting to grasp anywhere
| near as well as you would know the shape of the hand you're
| using so a certain amount of underactuated compliance makes
| the job a lot easier.
| stefanka wrote:
| I agree. But even then elasticity had to be taken into
| account (and maybe even gravity), if the object is very
| delicate.
| atrus wrote:
| Will Cogley has had a few different designs with tendoned
| hands.
|
| https://www.youtube.com/@WillCogley
|
| https://willcogley.notion.site/
|
| So, there are designs out there for that too!
| mclau157 wrote:
| Pollen Robotics and HuggingFace are doing a lot for robotics
| right now!
| ge96 wrote:
| Wonder if it will get adopted (huggingface robot) I noticed the
| eyes/cameras go behind the neck thing for sleep mode
| mft_ wrote:
| This looks like a nice, approachable robotic model of a human
| hand that can be printed and experimented with.
|
| But... is a human hand the best design for a robot to grip things
| with? Or could we surmise that the human hand evolved as a pretty
| good hand _given the materials and senses that were available to
| evolve humans from_ , while in theory a totally different design
| might be optimal for gripping when constructed from metal,
| plastic, motors, etc.?
| bigmadshoe wrote:
| It's easier for humans to train a human hand
| atrus wrote:
| Depends on what you mean by best ofc :P
|
| If anything, the human world is built for humans, so a lot of
| existing things are naturally compatible with human hands.
| Also, take into account flexibility. It might not be the best
| for one job, but it's really okay at a lot of jobs.
| magicmicah85 wrote:
| Is there a better design? I ask this genuinely, I really don't
| know but I suspect that the human hand is versatile enough to
| allow it to be programmable for a variety of tasks.
| mandeepj wrote:
| You can make it switchable! Think of it more like a dye, if
| that helps.
| a_wild_dandan wrote:
| Our modern world was built for hand-havers, so we build hand-
| havers for general interaction with the modern world. This
| vicious cycle will end, but a certain amount of inertial
| clunkiness is inevitable in nascent technological disruptions.
| Especially in moments as grand as the second industrial
| revolution.
| TechDebtDevin wrote:
| Would you prefer necrobotics!?!
|
| https://www.smithsonianmag.com/smart-news/scientists-use-dea...
|
| How long until human hands are put on robotics??
| jimhi wrote:
| This is the craziest thing I've seen in awhile
| LeifCarrotson wrote:
| A human hand is probably the most appropriate design for a
| robot to grip a variety of things _that were designed to be
| gripped by human hands._
|
| For any one specific thing, be it a doorknob, a rope, a sheet
| of paper or fabric, or a pair of scissors, there's probably a
| different design that's several orders of magnitude simpler and
| cheaper, and also much stronger and more reliable. Single-axis
| parallel grippers, circumferential chucks, vacuum cups/vacuum
| pads, electromagnets, cam lock and release mechanisms, and so
| on are common in industrial robotics.
|
| Assume your robot's only task is to grab a spool with a 35
| +/-0.5 mm ID core from from an infeed rack and place it on a
| spindle, you're not going to try to build a five-finger human
| sized servo-operated hand and tuck two of those fingers away to
| awkwardly pinch outwards from the inside, you're going to grab
| a Schunk JGZ concentric gripper off the shelf and plumb a pair
| of air lines to it. If it also needs to grab a tab from some
| tape on the spool and pull it into the machine, you're just
| going to add an asymmetric pincer like an angular tumor on two
| of the jaws - or graft on an entire separate parallel gripper
| like some polydactyl appendage, or tool-change, amputating and
| reattaching hands at will.
|
| I have also observed that humans are quite good at
| anthropomorphizing robot arms: a small, well-tuned motion can
| be universally recognized as a nod of agreement, shrug of
| confusion, wave of acknowledgement, or sigh of disappointment,
| even if the equipment is a bright yellow 6-axis piece of cast
| iron with menacing claws where the hand (or face? they're often
| the same) should be. Googley eyes and a "Hi my name is" sticker
| make this even more convincing.
|
| But if you need a single tool to grip a doorknob, a rope, a
| sheet of paper, a pair of scissors, AND an unknown variety of
| other arbitrary household objects... it's probably best to
| start with an approximation of the human hand. Also, while
| claws may be appropriate for a work environment with the robot
| inside a fence, in collaborative situations hands are just less
| intimidating.
| ctxc wrote:
| Good point, well put.
| Someone wrote:
| > For any one specific thing, be it a doorknob, a rope, a
| sheet of paper or fabric, or a pair of scissors, there's
| probably a different design that's several orders of
| magnitude simpler and cheaper, and also much stronger and
| more reliable.
|
| Also, if you're designing a robot gripper for any one
| specific thing, it's quite possible that you can tweak the
| design of that specific thing to make the task easier. As an
| extreme example, screws and screw drivers evolve in parallel.
| turtledragonfly wrote:
| As an aside, this "robot tentacle" paper was referenced in a
| recent HN story: "SpiRobs: Logarithmic Spiral-shaped Robots
| for Versatile Grasping Across Scales"[1]
|
| Seems like a pretty high bang-for-the-buck for versatility
| and capability with only a few cables controlling it.
|
| [1] https://arxiv.org/pdf/2303.09861
| numpad0 wrote:
| Why should _not_ we build robots that mimic us?
| hansvm wrote:
| Among other things, the ability to pretrain for a task by just
| copying human motion is pretty powerful.
| espadrine wrote:
| I agree that there are some robotic designs that unnecessarily
| mimic human limbs. I have in mind heads, and feet (instead of
| wheels).
|
| A hand however, is useful because so many manufactured objects
| have been constructed for their purpose.
| swiftcoder wrote:
| Feet are used for roughly the same reason a human-like hand
| is preferable - human-designed spaces tend to not be
| perfectly compatible with wheeled locomotion.
|
| The ability to negotiate stairs is table stakes for a
| household robot. It's already a pain when one's Roomba-like
| is defeated by a small ledge...
| jjk166 wrote:
| Well we aren't all wearing mecha-claws to improve upon our
| feeble human design.
| beAbU wrote:
| The human hand is arguably the best general purpose gripper of
| human-scale objects. Only took evolution a couple of hundred
| million years to figure it out.
|
| If you can limit the scope of things to be gripped, e.g. a
| sheet of paper, a baby chicken or a 100x100mm square steel
| girder then no doubt there is a better design out there.
| eichin wrote:
| Not exactly. The human hand is really advanced within the
| constraint of "you can't just arbitrarily replace damaged
| parts". If you can swap in replacement fingers, 3 of them is
| fine (and much easier to model and perform grasping
| calculations.)
| ygjb wrote:
| The question you are asking opens up a whole other field of
| questions. The amount of AI and robotics "in the field" is only
| going to increase. As that increase comes do we want to
| continue to build for a human capabilities and limitations, or
| do we want to build for machine capabilities and limitations.
|
| I think the ethical approach is to build for human capabilities
| and limitations. We have already seen what happens when we
| allow business to optimize for the lowest common denominator,
| and that is why we have regulations that emphasize
| accessibility. If we allow or encourage businesses to build
| robots that lack human capabilities and limitations that
| operate in the real world alongside humans, then even if those
| robots are assistive in nature (either a prosthetic robot hand,
| or a full blown humanoid robotic assistant), we will displace
| or redefine what humans are capable of, and diminish the role
| of and respect for human beings in our society.
| mandeepj wrote:
| The bigger or biggest question is - how much weight it can lift?
| If we assume it can lift half a pound, then what changes it'd
| require to make it lift 10/20/30 pounds and so on?
| micromacrofoot wrote:
| hands hold, arms lift -- a hand without an arm isn't going to
| have much strength
| horsawlarway wrote:
| Yes, but this is "bring your own arm" so the person above you
| can easily build the arm out to whatever specs they'd like.
|
| They probably want to know relatively important information
| like
|
| - Breaking force (how much force will break a finger)
|
| - grip force (How much force can the fingers exert to hold an
| object once closed)
|
| - holding force (combination of grip force and material
| properties [ex - friction] that gives you an idea how much
| force can be applied to prevent slipping)
|
| - closing force (How much force is exerted during closing
| [similar but distinct from grip/holding])
|
| Or, with a lot less specific detail but still generally
| useful as a starting point...
|
| - payload capacity (approximately how much can this safely
| manipulate)
| ortusdux wrote:
| I wonder if I have time to make one of these and then decorate it
| to look like Thing for Halloween!
| Brajeshwar wrote:
| Here is what I'm more keen on, rather than the human-like robots
| that we are all expecting. For instance, I would like a wall-
| mounted or floor-standing multi-arm robot that serves as a
| kitchen assistant. One can add or reduce arms as needed/desired.
| It is custom-equipped with a fire extinguisher, thermometer, and
| the usual must-haves for a kitchen. It will hold the cutlery,
| plates, and other items as needed. It will also advise on the
| likes of, "No, salts usually go in a pinch, would you like me to
| add in just about 5 grams?"
|
| Thus, similarly for the garage, the DIY table, etc. Just Arms
| would be good.
| thrance wrote:
| Tbh I would rather not have computer-guided knife-flinging arms
| in my home, be them on wheels or fixed to the wall.
| sroussey wrote:
| I have a parrot (whose beak is sharp enough, thank you very
| much) that loves to grab a knife out of the knife block and
| spin around with it.
|
| I have to put a towel over it though today he pulled the
| towel off and still grabbed the knife and was holding it up
| when I turned around.
| seanthemon wrote:
| It's a well known fact that birds aren't real and you must
| be a target now.
| 0_____0 wrote:
| Like a mischievous toddler with wings...
| scotty79 wrote:
| I always imagined robot hands hanging and sliding on rails
| under top kitchen cabinets.
| goopypoop wrote:
| perhaps sir would prefer... tentacles?
| bredren wrote:
| It slices, it dices...
|
| Seriously, though. Vassar Robotics (YC company) has an arm kit
| available for order now. The original ship date for my order
| just got pushed back due to an upgrade in the camera spec.
|
| It won't be able to hold knives (I don't think) but there are
| companies working to bring about your hoped-for wall arm right
| now.
| binsquare wrote:
| The world is designed with humans in mind, it's great to see
| robotics evolve in this direction to take advantage of that!
| poly2it wrote:
| Why was this downvoted?
| baq wrote:
| Literally the reason for all publicly traded robotics companies
| going up recently.
| breakpointalpha wrote:
| What jumps out at me is the $135 bill of materials.
|
| What a time to be alive!
| jjangkke wrote:
| Most hand related jobs upwards of $100 per 30 min
|
| If this Robot hand can do those jobs we could see some
| industries take a hit
| delijati wrote:
| https://m.youtube.com/watch?v=6pbgOmaBx34
| 0_____0 wrote:
| People have been making end effectors using hobby servos for
| ages. These servomotors are designed for use in an RC
| aircraft, they're light, cheap, and expendable.
|
| Industrial needs care not about weight, care less about cost,
| and care a great deal about capability, repeatability, and
| reliability.
|
| This is a cool project for a hobbyist but it's not meant to
| be a serious industrial machine.
|
| Edit: what is with this thread? Lots of very generic positive
| comments here but not much thinking about what this is
| actually useful for.
| pwndByDeath wrote:
| Woosh
| 0_____0 wrote:
| oh....oh no....
| johnmaguire wrote:
| I think the confusion stems from the fact that you're
| responding to a joke innuendo thread.
| trhway wrote:
| They just haven't watched the Big Bang Theory episode
| with Howard and the robotic hand:
|
| https://www.youtube.com/watch?v=OYryogNE8Ys
| stefanka wrote:
| Ooooh. For _that_ application you better have either
| enough elasticity or reliable force/torque sensors and a
| good control in place.
| ACCount36 wrote:
| ...that's how it was in year 2020.
|
| What you're missing is: today, we're nearing the point
| where actual general purpose robots become viable.
|
| Which means: the purpose of a robot is no longer to sit at
| a factory line and precisely execute the same exact motions
| on repeat 24/7. The purpose of the next generation of
| robots is to learn generalized behaviors, adapt to
| circumstances, and carry out circumstance-specific actions
| with active sensor feedback. Which means completely
| different requirements for effectors.
|
| Which means: repeatability can go get fucked, for one.
| lukan wrote:
| Without repeatability, good luck tuning your robot to do
| anything reliable.
| ACCount36 wrote:
| Real world isn't "reliable". If a robot can't correct for
| errors, it's not going to survive out there.
| stefanka wrote:
| > ...that's how it was in year 2020
|
| Humanoid robotics research was pretty popular in the
| early 2000s already, with remarkable, reproducible
| results not only in videos. It's definitively more
| present in the media now.
| stronglikedan wrote:
| > Lots of very generic positive comments here but not much
| thinking about what this is actually useful for.
|
| How can you say that when the person you are responding to
| is talking about what this is actually useful for?
| kakapo5672 wrote:
| It took me a a distressingly long time to understand this
| comment. I'm kind of concerned, and have vowed to get out
| more.
| MisterTea wrote:
| > upwards of $100 per 30 min
|
| That is why I'm self employed.
| echelon wrote:
| I can't wait for this to be put on a tall roomba base so it can
| clean my kitchen.
| Animats wrote:
| Feetech is selling actuators which are mechanically R/C type
| servos, but have a bidirectional computer interface allowing
| the control computer to find out what's happening at the
| servo.[1] This isn't new; Dynamixel has been doing it for over
| a decade. But not at this price point. This Feetech servo is
| $17, while Dynamixel units start around $70 and go much
| higher.[2]
|
| The parts list has "need to be strong" for many of the small
| parts, but they are 3D printed PLA plastic. That's the low end
| of 3D printing. None of the videos show the hand handling
| anything.
|
| So this is really the proof of concept model. If there's enough
| interest, someone could make the parts by injection-molding of
| something better, such as polycarbonate or glass-filled nylon.
| The total plastic volume here is so tiny that the plastic cost
| is negligible, and there's no reason not to use a high-quality
| engineering plastic.
|
| Nobody seems to do hobbyist injection molding much. TechShop
| had a desktop injection molding machine, the CNC milling
| machines to make molds, and even Autodesk Moldflow to design
| them. But nobody used those tools. A few university maker
| spaces have similar machines. Because most of the world's
| plastic stuff is made by injection molding.
|
| [1] https://www.feetechrc.com/
|
| [2] https://www.robotis.us/dynamixel/
|
| [3] https://makerspace.engineering.nyu.edu/machines/pim/
| mionhe wrote:
| Mold design is still difficult when the parts aren't dead
| simple. The software I've seen is okay with the simple stuff,
| but once you get even a little more complex you have to
| understand simultaneously how to design good parts for
| molding and how to design good molds, both of which are
| heavily dependent on the type of plastic you're using and the
| size of the press you have access to. Not to mention how to
| machine good molds from metal, which is a challenge all on
| its own due to surface finish and tolerance requirements (and
| weird geometry that makes the CAM choke...)
|
| In other words, we're not really there yet to bring that
| activity into the hobby realm. But I hope that we're not too
| far away.
| Animats wrote:
| They're little linkage parts, mostly flat.[1] Some of those
| holes are bearings. None of those parts are hard to make,
| but they need to be strong. They could be made by CNC
| machining, or in quantity by injection molding, or
| stamping. But tiny working parts in 3D printed PLA will be
| too flimsy for that hand to do much work.
|
| Totally fixable problem. Then this hand can go to work.
|
| If this thing catches on, someone might sell an upgrade kit
| with stronger parts. The designer is already considering a
| servo upgrade.
|
| [1] https://github.com/pollen-
| robotics/AmazingHand/blob/main/ass...
| mrbonner wrote:
| You haven't accounted for the 3D printer yet.
| stefanka wrote:
| It's one of best designs I have seen, I admit. But for that
| price you cannot get absolute encoders outside the motor,
| reliable force/torque sensors (think picking up a strawberry),
| tendons (thread below). It might be too limited for research
| and real-world projects unfortunately.
| aaronblohowiak wrote:
| Would adding AnySkin to the finger tips work? ( https://any-
| skin.github.io ) ?
| michaelt wrote:
| Ignore the fact the hand is as thick as a servo motor, for
| now, and just consider the palm width.
|
| This 2-finger hand is just below 4 inches wide, across the
| knuckles. By the standards of gloves for humans, this is
| already "X-Large"
|
| The SCS0009 servos are 1/2in wide and there are two for each
| finger. Adding two more servos would make it 5 inches wide,
| taking it into "XXX-Large" territory.
| proee wrote:
| Maybe this could be an add-on option for the K-Scale robot that
| is coming out soon? They want $1k for a 5 finger end effector
| hand.
|
| https://www.kscale.dev/
| glitchc wrote:
| This is great, but to make a comparable hand, we also need very
| sensitive sensors, at minimum pressure and temperature, across
| the entire surface area.
| falcor84 wrote:
| Absolutely, though I'd be ok with just pressure as a starter.
| agumonkey wrote:
| Anybody knows of similar projects for exoskeleton or support
| devices?
| lucidrains wrote:
| https://theopenexo.nau.edu/
| agumonkey wrote:
| thanks a lot
| Joel_Mckay wrote:
| Yes, it is a technology originally intended to make spacesuits
| less brutal on astronauts hand/wrist/forearm fatigue.
|
| Last I checked, project was shelved in 2020 for various
| reasons. =3
| schainks wrote:
| I swear I've seen this before somewhere..
| SequoiaHope wrote:
| Beautiful design and I love that it's in onshape with an
| aliexpress BOM. I might build this!
| fitsumbelay wrote:
| I love that it's cartoon style -- 3 fingers and a thumb instead
| of four
| FBISurveillance wrote:
| Great stuff. So 2x$135 and I'll finally get my t-shirts folded
| for me in the laundry room.
| TheAceOfHearts wrote:
| Does anyone know what design considerations, if any, might've
| gone into deciding to have 4 fingers instead of 5? And what
| tradeoffs that entails?
|
| I actually saw this posted a few days back on Twitter and had
| been wondering if there was any deeper consideration for the
| number of fingers. It seems like you save around $10 in parts by
| getting rid of a finger, based on the information in the BOM.
| p_d_r wrote:
| It looks like the width of the servos driving each finger makes
| a certain finger spacing necessary, and I bet five made for an
| awkwardly wide hand.
| michaelt wrote:
| Ignore the fact the hand is as thick as a servo motor, for now,
| and just consider the palm width.
|
| This 4-finger hand is just below 4 inches wide, across the
| knuckles. By the standards of gloves for humans, this is
| already "X-Large"
|
| The SCS0009 servos are 1/2in wide and there are two for each
| finger. Adding two more servos would make it 5 inches wide,
| taking it into "XXX-Large" territory.
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(page generated 2025-07-17 23:00 UTC)