Earlier quoted context omitted.
You can use an Arduino for virtually anything though. A robot arm can only move stuff around.
Arduinos are also $20.
Arduinos are like $3 if you buy Chinese replicas with the old bootloader ;)
Low Cost Robot Arm
131–140 of 258 posts
Re: Low Cost Robot Arm
#132Why not start with something less ambitious, like low cost robot platform able to follow people and carry stuff around and avoid obstacles. No arms, I am okay using mine to put stuff on and off it. When I had leg injury and used crutches, carrying stuff around suddenly became a problem. There are many people with impaired movement. And even without that, I often misplace things and it could help there. There are plen…
“Follow me” luggage exists
https://www.aristavault.com/products/follow-me-smart-luggage
Re: Low Cost Robot Arm
#133I'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 po…
- 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) Which of those can/cannot be done and why?
> Arm wrestling a toddler?
The most common designs of six-axis robot arm don't have the 'rotate forearm sideways' joint needed to arm wrestle.
> - Handwriting notes for small jewelry brand?
Possible: https://en.wikipedia.org/wiki/Autopen
> - Drink mixer?
Possible: https://www.makrshakr.com/ (arguably more of a showy entertainment item than anything else)
> - Handing towel when in the bathroom, then getting a new one?
Manipulating flexible materials is difficult. As is navigating through a house with locked bathroom doors and suchlike.
> - Setting up my morning espresso?
Depends if you're willing to broaden your definition of 'robot' to include bean-to-cup machines.
Re: Low Cost Robot Arm
#134I started working on a similarly sized arm. I've got a use-case, long time friends with a glass blower. I was thinking of using it to make faceted glass pendants. They've got a faceting machine but it is manually operated.
The hard part is repeatability. You need tight tolerances and each joint in the arm adds inaccuracy the further you get from the base. If the base has 1mm of wiggle, the 20cm arm has 4mm wiggle at the end, and the arm beyond it has even more.
You also, for faceting purposes, need much finer resolution than an ungeared servo will have. Gearing it is tricky because you want backlash to keep the join tight, but not so much that it has high friction when moving. You don't really want to use a worm gear because they're both slow and overly rigid. So a cycloidal gear is the best bet for the gears in the arm. You also need real servos with some amount of feedback because grabbing at glass is sketchy at best.
I was estimating 1-2k build cost, bulk of that is in the gearboxes.
Re: Low Cost Robot Arm
#135Earlier quoted context omitted.
There have been a few around, but the limiting factor (as you can see from the BOM in the link) is the cost of the actuators. They get expensive fast.
If they don't have to move fast, could you DIY an actuator with a stepper and a threaded shaft? Steppers are pretty cheap thanks to 3D printers.
There are arms using steppers and 3d printed epicyclic or cycloidal drives.
Re: Low Cost Robot Arm
#136Earlier quoted context omitted.
An impractical use would be to have a few of them replace monitor arms in a multi monitor setup. You could then rapidly switch between a few configurations. Also, have one to stir pasta in the kitchen.
On the topic of automatically stirring pasta, I saw this the other day! https://www.amazon.com/StirMATE-Automatic-Variable-Self-Adju...
That is interesting and Amazon has a great algo for matching it to laboratory equipment consisting of hot plates and magnetic stirrers.
Re: Low Cost Robot Arm
#137Earlier quoted context omitted.
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. I think the limiter on smaller arms is quality servos with real location encoders - this one costs a couple hundred bucks for motors. Not claiming the software is easy! But I think sourcing parts is (or has been) really hard.
> 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.
Re: Low Cost Robot Arm
#138A $250 robotic arm is really a price consumers can reach. How does it perform in practical scenarios in terms of durability and precision? Is it functional?
Re: Low Cost Robot Arm
#139I'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 po…
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 think the main issue is inverse kinematics and path planning.
Which is partly why SCARA is popular with amateur robot arms, the maths is simpler.
Re: Low Cost Robot Arm
#140Why not start with something less ambitious, like low cost robot platform able to follow people and carry stuff around and avoid obstacles. No arms, I am okay using mine to put stuff on and off it. When I had leg injury and used crutches, carrying stuff around suddenly became a problem. There are many people with impaired movement. And even without that, I often misplace things and it could help there. There are plen…
> low cost robot platform able to follow people and carry stuff around and avoid obstacles. So, basically autonomous self-driving mini vehicle. Сompanies spend billions on self-driving cars with quite limited luck.
> Сompanies spend billions on self-driving cars with quite limited luck.
That's in part because it needs to be very reliable to not kill people.
If the worst that can happen is killing a garden gnome or running over someone's toes you can tolerate more error.