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Low Cost Robot Arm

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Re: Low Cost Robot Arm

#91

Post by Max-q »

greggsy wrote: post #40
isquaredr wrote: post #12

The geek in me is drooling, but are there any practical home uses others have found for robotic arms? Hacking is always more fun with a good project

I’d use it to pick through and sort the massive pile of Lego my children leave behind after an Easter long weekend. Seems trivial to do identification based on the high quality corpus of block databases. Wouldn’t have to be super quick - you could just leave it running overnight. I’m sure someone’s written an interesting paper on the ideal sorting algorithm too (i.e. large things > small things vs. ‘just pick up and…

I think the easiest way to collect the Lego pieces from the floor is by using a vacuum cleaner.

Then look at the sorting as a separate problem :)

Re: Low Cost Robot Arm

#92

Post by 7373737373 »

0xEF wrote: post #89
7373737373 wrote: post #75

Earlier quoted context omitted.

A lack of applications hasn't prevented the sale of a large number of Arduinos lol

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 :)

Re: Low Cost Robot Arm

#93

Post by euroderf »

isquaredr wrote: post #12

The geek in me is drooling, but are there any practical home uses others have found for robotic arms? Hacking is always more fun with a good project

Drinks mixer! Line up the booze bottles and other stuff.

No need for brute strength. Tolerances of one or two millimeters are mostly fine.

Re: Low Cost Robot Arm

#94

Post by amatic »

TomK32 wrote: post #82
Ekaros wrote: post #77

Earlier 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.

Wouldn't be the easiest way to program a robot to "show" it its task by simply moving the arm a few times in the paths it has to replicate afterwards?

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).

Re: Low Cost Robot Arm

#95

Post by michaelt »

brcmthrowaway wrote: post #35
jerzmacow wrote: post #2

Wow, I was building a Thor 3D printed arm, and this project looks way better! I think I'm going to Pivot. Side bar: these servos are a game changer.

Are the servos better than SG90?

They're "smart" which means you can form a serial bus of them, query individual motors' encoder positions and motor temperatures and whatnot, adjust the PID parameters yourself, and so on. You can also daisy-chain them together, which might reduce your cable routing problems.

Downside is when they break, you're out $50 or more - and you're going to break at least one. And the manufacturer wants you to operate them at 11.1v which isn't very convenient. And when it comes down to it, it's still got plastic gears, a plastic case, and enough backlash to be noticeable.

Re: Low Cost Robot Arm

#96

Post by moffkalast »

potatoman22 wrote: post #3

I printed a robotic arm for school. Unfortunately, we weren't using a high quality enough printer, so the tolerances were off and things didn't slot together well. I'd recommend people to know the precision of their printer before setting off to build this.

It's not so much the printer's fault as the slicer's. Calibration is key.

Re: Low Cost Robot Arm

#97

Post by Itschris48 »

7373737373 wrote: post #69

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 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?

Re: Low Cost Robot Arm

#98

Post by rini17 »

Why 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 plenty of toy robot undercarriages on aliexpress but too small (under 20cm largest dimnsion) to be practical.

Re: Low Cost Robot Arm

#99

Post by sgu999 »

michaelt wrote: post #81
greggsy wrote: post #40

Earlier quoted context omitted.

I’d use it to pick through and sort the massive pile of Lego my children leave behind after an Easter long weekend. Seems trivial to do identification based on the high quality corpus of block databases. Wouldn’t have to be super quick - you could just leave it running overnight. I’m sure someone’s written an interesting paper on the ideal sorting algorithm too (i.e. large things > small things vs. ‘just pick up and…

> Seems trivial Said like someone who's never tried it :) For a start you're going to need a camera. Maybe more than one. You want depth sensing? Even an cheap choice like a RealSense is going to add another $250 to your costs. And you'll need a sturdy mount for it, the robot's going to vibrate the table and you don't want to suffer motion blur. Got the camera in a fixed location, over the area you're picking from? T…

> Even an cheap choice like a RealSense is going to add another $250 to your costs

fyi, Luxonis is selling some for $150, I'm still meant to try them but they look quite good

Re: Low Cost Robot Arm

#100

Post by numpad0 »

ipsum2 wrote: post #29
antoniuschan99 wrote: post #25

Earlier quoted context omitted.

I have a dobot mg400 but there are quite a few others: uFactory, elephant robotics, annin, dorna, epson (vt6L and their scaras), and lynxmotion is releasing their ses-v2.

Wow, thanks for the list of resources. My problem with most robot arms are either they have small payloads, accuracy isn't very high, are too slow, or software support is terrible. Do you have any specific suggestions for 6DoF? The MG400 looks to have 4.

You don't want a cheap && powerful && fast robot in your home! Let alone sell a bunch of.
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