I'm surprised (or perhaps very unaware) that there doesn't seem to exist a company yet that mass produces cheap, high quality, reasonably standardized robot arms. So many things like 3D printers or CNC machines have entered the consumer/amateur level price realm, but this seems to be something still largely unexplored. Seems to have Arduino/Raspberry Pi scale potential, but I haven't heard of a name/ecosystem that popular yet
I worked for a startup developing robot arms for a while. What we found was that giving someone a robot arm - even one with reasonable APIs and no cost to them - didn't really help because the hard part is making useful automations. Mostly people spent a few hours playing with the arm and then put it on a shelf.
Every use case is completely different and is a lot of work. Even when you get something working, accidentally shake the desk or crash the arm into something and all your coordinates are broken and you have to start again.
Not to mention the actual mechanics are really complicated - to have a meaningful payload at 50cm reach you end up with really high torque at the base joints (which also need to have super-high accuracy), which requires expensive gears and motors. None of that is cheap.
Then you get to safety - an arm that has a useful payload is also quite heavy, and having that amount of mass flailing around requires safety systems - which don't come cheap.
It's a bit like hardware no-code - you can't make an easy to use robotic arm because programming it is inherently hard. I think the only thing that will change that is really good AI.
Do you know if anyone has tried building an arm that uses spatial positioning techniques from augmented reality, like structured light or pose tracking[1], to understand the position of the arm in space without resorting to "dead reckoning"?
It seems like that kind of approach would increase the physical tolerance and reduce the programming complexity, since you know both a) where the arm is supposed to be, and b) where it actually is.
Yep. Interestingly, there has been a lot of recent work on models like RT-2 that might be capable of automating this for simple tasks. We might be at the point soon where that startup would have been viable!
There is a reason there is no standard hobbyist-grade robotic arm.
People think they can build their own robotic arms for leas than a "real" robotic arm costs, but the do not account for wobble or repeatability.
With all due respect to the person who posted a design for a robotic arm made with RC servos on HN, I would like measurements of the repeatability. Have it draw the same pattern on a piece of paper every day for a week. Show me how closely the 7 lines overlap. I doubt that it can draw such a thing; it will tear the paper or get jammed without the strength to tear the paper.
Source: I've been building hobbyist robots since the 1980's, researched robots in the 1990's including a masters thesis, and teaching robotics for most of the last decade.
The hobbyist market is pretty forgiving of repeatability issues. The Ender 3 introduced many people (myself included) to the 3D printing world and is known for its problems.
Horses for courses. Nobody's going be trying to weld car chassis with one of these, true, but also a hobbyist wouldn't want some ABB or FANUC or whatever industrial arm in their house where it could kill someone. These small light duty less-rigid robot arms are fine for what IMO is the really exciting stuff like modern machine learning control research, which is exactly what this guy's doing with them.
^Modifying cheap servos so that a robot arm can repeatedly insert a pencil lead. It's a lot of work though.
Most interesting application though fall out of the scope of old-fashioned robotic arms, i.e. when you need to sense the real world in a non controlled context. For instance to develop a robot that can trim wilted flowers, you'll need to measure the real world, and as soon as you do that, you can just sense your robot arm too, no need for fancy, ultra-precise actuators.
Do you really need the $6,129.95 & $3,549.95 robot arms for the kind of application described ? I doubt it. I'm not a robotician, and would love some feeback on this idea.
Is this not something that can be addressed with cameras and (maybe) learnt approaches now? You don't need blind repeatability if you've got good visual monitoring to close the control loop, you just (just!) need good accuracy and low latency from video to motor control.
Why not just throw a SteamVR/Vive laser tracker onto the end of the arm and use that to close the loop? They claim sub-mm precision at room-sized distances, so it should be even better if you had it basically mounted on the base. If you wanted to get fancier you could build it into the end effector w/ one of these?
https://tundra-labs.com/products/tl448k6d-vr-system-in-packa...
Why are you so negative towards this? It's just an Open source project... who cares how good it is. It's a great way to learn, and play, and experiment.
That post is in the category „all knew it was impsossible until some stupid with no idea made it“
That somebody was 4 decades failing, does not mean that at some point it won‘t be possible. In the last 4 decades the prices have lowered and the quality is much better in the RC world, if you know where to buy.
> Why are you so negative towards this? It's just an Open source project... who cares how good it is. It's a great way to learn, and play, and experiment.
I did not mean to criticize a hobbyist project for existing.
I meant to say "There is a reason there is no standard hobbyist-grade robotic arm."
Skimming through this threads and the various answers to the multiple "has anyone found a use for a robotic arm?" questions will explain why there's no such company. There simply is no consumer-grade market.
Arduinos are for prototyping, which makes the application fairly massive. The company I work for used them to develop one of our machines before we moved to a custom board. So, I'd say they are pretty useful.
Agreed, they certainly can be/are useful (and fun!), in a multitude of ways, but all too often I've also encountered peoples' "complaints" that they bought a bunch and now don't have a use case for it/are searching for one :)
That's because a toy engineering project is still an engineering project and will be way more work than you think it is, no matter how much work you think it is. It's hard to maintain that energy for long when it's not your day job (sometimes even when it is, tbh).
LOL. I often tell people online that they're better off downloading the free Arduino IDE or playing around with the Wokwi simulator until they have a good idea of what they want to build and whether or not it's within their capabilities before buying parts.
I've built a lot of custom arduino-based projects for other people and a substantial fraction of them are the "I bought a bunch of stuff, but I don't have time to learn how to program it" types.
They do, but cheap is ~10.000€ currently for a general-purpose bot with 1.2m reach. You get a high quality machine and software for that. Note that a robot without really good kinematics software is borderline unusable. Also, besides the arm you need the control box which reliably delivers power and commands in real-time. That adds quite a bit of cost too.
Ask yourself - what problem are you trying to solve?
After you've defined it, you'll quickly learn that there's much simpler and cheaper solution than 6DOF robot arm in almost every case.
And if you actually do need it, in those cases you'll find that 10-20k is actually pretty cheap all things considered.
With my understanding 6DOF robot arms are used when you need to be flexible. Today you do this tomorrow (or in a couple of months) you will need to do something else. The more diverse set of things to do the better. But if you need to do the almost exact same thing many times over for a long time it is better to design a production line that doesn't use 6DOF robot arms at all.
Also I have understood that robot arms are in real life rather complicated to program to operate correctly. So any process would take substantial effort. Magnitude harder than controlling some relays or reading some sensor data.
> I don't know, but I think the big real industrial kind can really really hurt or kill people.
Not a robot arm, but I worked on a project where the customer wanted to use a commercial motion platform as part of a simulator-based training system for boats. They thought they could just put it in the corner of their boat shed and get training but were amazed when they realised how dangerous it could be to passers-by, especially if it moved unpredictably when someone was standing nearby without paying attention. It went from 'we just need some crowd control barriers' to a full metal cage that was also integrated with the building fire alarm system so that it would stop cleanly if there was some sort of emergency elsewhere.
Other motion-platform-based hilarity ensued when it was discovered that the commercial software model they were using to drive the sim could in some circumstances capsize the virtual boat.
I've explored the idea of using super cheap servos to build a robot arm/tentacle to pick cherry-tomatoes and it seems the only reason you'd want to use location encoders is in tasks that require high precision in an open-loop system (the robot is blind to its environment but has info about his own body). To me it seems you can get rid of this requirement if you allow the robot to sense its environment using cheap, 800x600 cameras with depth estimation ML algos and get away with the accumulated imprecision of sequential servos by coupling to each servo a high accuracy/small angle servo (just modify the servo's gear box). As for the gripper mechanism, you don't need fancy force sensors, just use a kirigami effector [1]. See also mobile-aloha [2].
In a controlled environment - where the object to pick up, for example, is always in exactly the same location - you could do that. If there is any variation in the location of the object, you need vision to localize it each time. You need a camera, maybe two, and probably some kind of 3d perception, which is an unsolved problem at the moment (well, not solved in a general way, there are some solutions for specific objects).
Yes, they have systems to learn this way, but it assumes the environment is controlled (always) and the task identical (always).
Lots of automation works this way, but it actually limits the applications quite a bit.
A robot that can safely work along side people (i.e., a "cobot") and adjust to environment changes and changing work patterns is a whole different beast.
Sensors too. E.g. force sensors are important for dexterous manipulation and safety. But they are all expensive, bulky, imprecise, or require constant recalibration, or all of the former.
Our robotics Prof used to quote his industry peers: "The best sensor is no sensor."
Have to disagree with this. The major limiting factor is the software and lack of applications. If there was a killer application it would be much easier to sell. Then the numbers would drive the prices down.
For a useful robot arm, you need high forces/torques. Usually, this is achieved by high ratio [1] gearboxes between the motor and the joint. Those are expensive, and inefficient and make estimating the output force via the motor current almost impossible.
I don't think we've figured out how to make good cheap mechanical actuators. I think that engineers make do with inaccurate actuators by changing the mechanism around it.
Robot arms need a level of reliability that isn't cheap yet.
- Arm wrestling a toddler?
- Handwriting notes for small jewelry brand?
- Drink mixer?
- Handing towel when in the bathroom, then getting a new one?
- Setting up my morning espresso? (grinding the beans and turning on the coffee machine)
Like arm wrestling a brick wall; if you can push it over then you win, if you can't push it over then you lose - either way there's not much fun in it. And if it can beat the toddler it risks injuring them because neither of them really understand what's happening and what the risks are. The arm can't stop if the toddler says 'ow'.
> "Handwriting notes for small jewelry brand?"
Can be done already with a commercial 2D plotter: https://www.axidraw.com/ . It costs twice as much as this arm, but you don't have to build it and it already has "software for realistic handwriting" and there's a company to get support from.
> "Handing towel when in the bathroom, then getting a new one?"
Is the arm big enough to be useful for that? It appears to be shorter than a typical human arm so it would be cheaper, simpler and quicker to put the pile of clean towels a foot closer to the shower where the robt arm is sitting, and not have the robot arm at all. Plus you wouldn't have to deal with electricity in the bathroom or dripping water on the robotics as you reached for the towel it was handing you. (Are you thinking of a robot arm with cameras for feedback of where it's positioned? Cameras in a bathroom won't be popular with everyone no matter how much you promise they are innocent).
> "Setting up my morning espresso? (grinding the beans and turning on the coffee machine)"
Simpler and cheaper done with a timer mains plug which you can get for under $10. Put the beans in and load up the coffee machine the night before (work you'd have to do anyway) and have the timer start them in the morning. If you expect the robot arm to unseal a bag of coffee beans, measure some out, deposit them in the grinder, close the grinder, and close and seal the bag after, you'll wake up to spilled beans and unsealed bag a lot of days before you get that working reliably. Instead of $250 plus weeks of effort to speed up this 2 minute task(!) you can get a Keurig / Nespresso pod coffee maker for less than $100.
> "Drink mixer?"
How much spilled wasted alcohol, plus time of disassembling and cleaning your robot arm and the surface it sits on, and the floor, or finding the bottles, unscrewing the tops, handing them to the arm, waiting for the arm to slowly pour them which you could have done quicker, then putting the tops back on and putting the bottles away yourself, then putting the drink stirrer into the arm, then waiting for it to mix the drinks which you could have done yourself quicker, before you decide this was not a good use of time or money? (How often do you drink mixed drinks anyway?)
The robot isn't going to learn to do the task better next time like a human could so if you have to get involved in the task at all, you may as well do it yourself. And if it's a 15 second task like "reaching for a towel" what are you doing with your life trying to automate that? Roomba saves a lot of time, a lot of annoyance, it could be worth it even if it does an inferior job - because you can leave it running over and over and over. Same with a robot lawnmower, if you just glance around to make sure there's no pets or children in the way then let it go, it can save you a good chunk of time and if it goes wrong you just get a patchy lawn or dusty floor and it can retry tomorrow. But handing you a towel or mixing you a drink saves you almost no time, but if it goes wrong you get a broken bottle of sticky drink all over or a pile of towels on the floor, which has undone months of 'time saved' in one go.
State of the Art public robot arms include Boston Dynamics' Stretch[1]. It's not for sale to the public, the price isn't public, it's got 18 suckers on a flat tray and runs on a wheeled base and looks like the size of an armchair. Boston Dynamics' Spot the walking dog robot was launched in 2020 for $75k and was explicitly not safe for use in the home or around children.
Do you genuinely think they will improve to the point of having finger style grippers, dexterity and adaptability to grind coffee, mix drinks and pick towels, and be on sale to the public, safe for use in the home, for $250 (or $2500) by Jan 1st 2030? I would be very surprised.
(Can you get a robot arm today, for any price, to help a quadraplegic open their mail, bring a drink with a straw in it to their mouth, lift them into a sitting position, hold a book in front of them and turn the pages, or ... do anything helpful? I'm not aware of any, but haven't been looking specifically).
Yes you could probably build a robot today which hands you a towel from a pile, reliably and swiftly, or selects the bottles of alcohol and opens them and pours and mixes a drink - in a carefully controlled and lit environment where none of the lids or corks are stuck and the glasses are all a similar shape and size and nobody is allowed to be near it - I don't say it's impossible with today's tech, but it would cost a lot more than $250. A hundred or a hundred thousand times more, while being far far more limited than a human.
