YHK - yet another hacker news clone

Stringman, an $800 open-source room scale gripper robot

123 points nharada 3 hours ago 66 comments

BHSPitMonkey 1 hour ago | parent

I love the ingenuity, though it's all fun and games until someone or something manages to yank down on one of the cables...

HeyLaughingBoy 1 hour ago | parent

Probably sell more of them as expensive cat toys.

yathern 1 hour ago | parent

Very clever - and I love "tension is all you need"

bigwheels 1 hour ago | parent

It's an interesting concept, but I think I'll hold out for the full-body humanoid version.

There is an undeniable allure to the idea of a bipedal chassis realizing I'm an inefficient drain on corporate resources, then stabbing me to death while I sleep due to a minor Terms of Service violation.

weirdish 1 hour ago | parent

I'm sure with a little ingenuity you could rig up stringman to stab you to death!

fidotron 1 hour ago | parent

Getting it to be forceful enough would be a bit interesting. Could certainly slowly strangle you in the cabling.

nancyminusone 1 hour ago | parent

Depending on how high your ceilings are, dropping items from height could be quite uncomfortable.

monkmartinez 1 hour ago | parent

It could also strangle you super fast, see here; Red Cable Robots Video[1]

[1]https://www.youtube.com/watch?v=AIr0ZtVVnBA

embedding-shape 33 minutes ago | parent

> Could certainly slowly strangle you in the cabling

Reminds me of the engineer who accidentally strangled himself with his contraption:

> He devised an elaborate system of ropes and pulleys to help others lift him from bed. He became entangled in the ropes and died of strangulation at the age of 55. However, he is better known for two of his other inventions: the tetraethyl lead (TEL) additive to gasoline, and chlorofluorocarbons (CFCs). - "The Man Who Accidentally Poisoned the Planet Twice": https://en.wikipedia.org/wiki/Thomas_Midgley_Jr.

jacquesm 25 minutes ago | parent

That's straight out of Douglas Adams.

"Grunthos was reported to have been "disappointed" by the poem's reception, and was about to embark on a reading of his 12-book epic entitled "My Favourite Bathtime Gurgles" when his own major intestine, in a desperate attempt to save humanity, leapt straight up through his neck and throttled his brain. "

jacquesm 28 minutes ago | parent

Gravity assist...

fidotron 14 minutes ago | parent

Honestly I had been thinking more in terms of a crossbow/harpoon type attachment. Fire, rewind, tension up, fire again etc.

smnplk 1 hour ago | parent

This reads very futuramaesque

doctorzook 1 hour ago | parent

Slow and horrible, please.

adamsmark 58 minutes ago | parent

Poison tipped syringe!

KumaBear 1 hour ago | parent

Why humanoid though. I’d want the most efficient design to complete the task at hand. Even if the thing looks like a hybrid of an octopus meets Freddy Krueger

dyauspitr 1 hour ago | parent

The difference is, I want the most efficient design that can complete every physical task that I can. That design is probably humanoid.

schiffern 33 minutes ago | parent

In non-murder tasks, humans are already obsolete. Our remaining economic value is solely alignment arbitrage, eg solving CAPTCHAs, murder, submitting 'human' papers, etc.

Given abliterated open models, Stringman is coming for our last remaining job!

app134 14 minutes ago | parent

The world is already designed for the humanoid for factor. Instead of designing 1001 specialized robots, why not design one that can already use the stuff we have lying around?

tootie 16 minutes ago | parent

The desire for humanoid robots is purely aesthetic and almost certainly suboptimal. Ceiling mounted is actually a much more plausible option. Next most likely is something more like R2D2. A rolling garbage can with an arbitrary number of specialized appendages. Humanoids seem like a real dead end to me.

kevin_thibedeau 9 minutes ago | parent

Their benefit is they can operate in any space designed for a human without custom modification. No wires to get in the way with an assistant robot that interacts with the existing built world.

hathawsh 6 minutes ago | parent

We might be at the beginning of a golden age for inventors. Robots of all shapes and sizes, with highly variable price points and specialization. Still, the first challenge for R2D2 is probably stairs.

pseidemann 15 minutes ago | parent

This also elegantly defines the meaning of (modern) life: comply.

strangattractor 8 minutes ago | parent

Sorry - Over price claw machine:)

monkeydust 1 hour ago | parent

Super smart but it's one of those ideas that hopefully gives someone else in this space another idea that leads to something that could mass scale and I would buy. Love the ingenuity though.

iJohnDoe 1 hour ago | parent

It's an interesting concept. If you scroll through the page you'll see it's actually pretty strong. The blanket pick up video should actually be the first video.

My fear is that a company that has the money to build and manufacture this will rip off the idea and use their resources to polish the concept. With a lot polish, this type of thing can be useful in certain environments.

HeyLaughingBoy 1 hour ago | parent

So, you fear someone else making it "useful in certain environments?"

Karliss 6 minutes ago | parent

Cable robots have existed for decades this is not a new concept. Anyone who wanted to rip it off could have done it long time ago.

stainablesteel 1 hour ago | parent

get funding for this, it's worth a shot

conductr 1 hour ago | parent

My thoughts while watching the video

Robot picks up clothes -> this is stupid

Robot picks up kids toys -> this is brilliant

In reality though, I think the cables will never work in a household situation. It's a interesting concept and I'm sure it was fun to build :) Makes me wonder what commercial application this would work for, I'm sure there's something out there that would benefit from this over waiting on humanoid tech

simon01 1 hour ago | parent

When I was 12, it was my job to pick up all the toys my much younger sibling had thrown around all house. I spent an hour every day doing that. I wish someone had gave something like this back then. It would save hundreds of hours

conductr 53 minutes ago | parent

lol. I had much younger siblings too and have memories of pulling out the dust pan and broom if I had to clean after them. Luckily wasn’t my daily job, yikes!

nomel 1 hour ago | parent

A fourth cable would allow you to keep the other three constrained up high, with fourth being to lower. Would require some close looped control to eliminate swaying though.

BorisMelnik 58 minutes ago | parent

I'm thinking about the legos with chocolate milk spilled all over it, or the bowl of cereal sitting on top of the kids toys.

I wonder how it would handle something like a blanket or pillow on top of the toys

Karliss 16 minutes ago | parent

Only widespread commercial application of cable robots I have seen is cameras in stadiums and concert venues.

I guess in most industrial use cases it makes more sense to have a robot stationary and move the parts around with conveyors. Doing it that way allows to pipeline and parallelize the manufacturing process. In contrast the large operating volume covered by cable robot needs to be served by single robot exclusively.

d--b 15 minutes ago | parent

Same here I had a 3rd step in my thinking though:

Robot can't open ikea drawers -> this is not gonna work

tootie 7 minutes ago | parent

For $800 I think it's pretty incredible. If something like this is plausible then you may see a future version built with rails.

HeyLaughingBoy 1 hour ago | parent

I was actually just thinking about something like this this morning. Mainly because I was idly wondering if the kinematics would work with just 3 supporting cables. Intuitively, it seems like it should, but I haven't bothered to research it yet.

Anyone?

jameshart 1 hour ago | parent

Range of motion would be confined to the space beneath the triangle bounded by the three anchor points. Most spaces are rectangular, so bounding it to four corners would seem likely to give a more useful range of motion.

stickfigure 1 hour ago | parent

Perfect for your triangular rooms!

wave_function 54 minutes ago | parent

3 cables should work. Each cable length is a single parameter that defines a sphere around the mount, and the intersection of three spheres defines a point.

I suspect the reason they chose 4 is that 3 cables would limit you to a triangular region, so you’d only be able to access half the room.

swid 42 minutes ago | parent

You can join two of the cables together that come from each corner unit into one. each unit - still with an eye hole in another corner - moves the cable left or right. With the opposite corner unit, you can pick X,Y on the ceiling. I'd put the third cable in the grabber, which can be used to lower it to the floor.

Probably if you went this way, you'd want to measure each ceiling cable so it is about X+Y length, or otherwise the slack needs to be held somewhere.

This is one less actuator than their system if I understand them, and they are not counting the gripper itself.

yeehawjared 1 hour ago | parent

LOL @ tension is all you need

jayd16 1 hour ago | parent

Can it make a bed? Actually, can it lift a comforter? Can it fold towels?

I think the form factor is actually fine but the specs probably need a boost.

monkmartinez 1 hour ago | parent

These things are scalable... but I am not sure the PAF "partner acceptance factor" would pass depending on what you wanted to accomplish.

stickfigure 1 hour ago | parent

Realistically, this has one application: The kids' room. PAF might be higher than you think.

smnplk 1 hour ago | parent

Looks good, but I am waiting for Droneman

monkmartinez 1 hour ago | parent

Awesome!!! I love projects like this.

Reminded me of the Hangprinter https://github.com/tobbelobb/hangprinter which has been around for around for long time... always wanted to build one.

ETA: https://hangprinter.org/

bigcat12345678 1 hour ago | parent

Come on this is not up to the standard. Consumer product must be highly polished, it can be fully unfuncyional, but it needs to look good. This one is close to my 8 years old son's tape+random lego pieces...

darkmighty 1 hour ago | parent

I didn't understand if exactly this feature is available, but I think it would be a good idea to let the strings actually come off each motor completely when yanked hard. Interesting idea :)

Hasz 1 hour ago | parent

To those asking about more demanding tasks, I totally think this thing could scale up, reminds me of Maslow CNC (and predecessors):

https://www.maslowcnc.com/

basically a cable driven 4x8 sheet router.

MisterTea 46 minutes ago | parent

I've been wanting to build a cable robot for Halloween which flys a ghost around the front yard with a vision system that detects people passing by and the ghost floats towards them and follows them.

swid 35 minutes ago | parent

They designed the cables to go down into the room, instead of from the ceiling - seems like that is a deal breaker for most environments actually, because you need the whole room to have open space just to drop it to the floor all over.

They say they use 4 actuators, but if they only used 3, this problem would be solved.

Instead of independently controlling all four lines, you can join the lines leaving each corner unit and then just move the line left or right instead of reeling two different lines in and out. You still use the corner eye loops, and you use two cables that are X+Y in length. This allows you to pick a point on the ceiling. Then a third actuator and line in the gripper itself could lower itself to the floor.

cloudfudge 33 minutes ago | parent

If I understand what you're suggesting, wouldn't this result in a lot more swinging since the gripper would be suspended from a single point directly above it?

CyLith 30 minutes ago | parent

That too is a solvable problem if you have the sensors for it. You can critically damp or choose a motion profile to have essentially no swing.

swid 28 minutes ago | parent

You seem to. That is a good point I hadn't considered - the tension from the sides holds it in place. Maybe we need to use a telescoping arm (which doesn't seem practical, I'm mostly joking). It might still work, but I imagine if you don't grab it on the first try, you may have to go back to the ceiling. And hope there are no strong drafts in the room.

EDIT: maybe lower it on three lines instead of one?

carb 24 minutes ago | parent

How do you prevent having to grab things perfectly in their center of mass? (Because that requirement seems limiting)

Rigid objects would result in the gripper twisting, but the current design could offset some of that by pulling harder in one direction?

swid 21 minutes ago | parent

With the video, it is casually dropping things like clothes and toys into a bucket, so I'm not sure it would be a big deal. But you could also lower it via three lines instead of one, so there is something to counteract that.

nlitsme 18 minutes ago | parent

Seems to work for people who basically have very empty rooms, and very orderly piles of things.

SoleilAbsolu 3 minutes ago | parent

And are short enough to walk around without getting clotheslined by the cable!

delichon 15 minutes ago | parent

They compare it to a robotic arm, but they are a natural combination. Two arms, even, floating above it all, could scratch the dog, make breakfast, and maybe someday, fold a fitted sheet.

stronglikedan 10 minutes ago | parent

Even if all it can do is scratch my back, I'm in!

Ey7NFZ3P0nzAe 7 minutes ago | parent

Awesome! Though I'm thinking that you can do MUCH MUCH more things with 2 grippers than with one. Has all been tried in terms of weight management to instead of having a motor in the air with a gripper, putting two motors on each end corner of the ceiling that can pull a line tethered to a (in the air) pulley system that grasps? You could then have say 4 lines to pull (1 left grip, 1 right grip, 1 to adjust both gripper's distance, 1 to rotate the in the air platform).

structuredPizza 5 minutes ago | parent

I was working on something similar, stoked to see this type of project making it out of the labs! The inspiration for most similar systems are industrial settings with automated bridge cranes which are fantastic, almost surgical when everything is symmetrical in the active environment.