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Low Cost Robot Arm

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Re: Low Cost Robot Arm

#51

Post by Terr_ »

IshKebab wrote: post #43
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…

Picking up and sorting Lego with a robot arm is pretty much a state of the art research project (a few years ago at least), not a hobby project.

I imagine it is strongly affected by whether the pile is already decomposed into individual bricks or not.

The analysis and disassembly of a combined set of bricks can frustrate even human eyes, brains, and fingertips.

Re: Low Cost Robot Arm

#52

Post by otikik »

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…

My impression is that the fastest/easiest way to do it would be putting all the pieces inside hopper with the selector at the bottom. Perhaps using compressed air to push the falling pieces into different containers as they fall. I believe there’s already something like that in produce factories, separating vegetables by state/size.

Re: Low Cost Robot Arm

#53

Post by [deleted] »

cs2818 wrote: post #48

As a longtime Dynamixel user I agree the U2D2 adapter is pricey in comparison to other options, but I would like some quantification of the “latency is very high” claim. I have always found it to be a sure bet for low latency (~1ms) across a wide variety of platforms.

[deleted]

Re: Low Cost Robot Arm

#54

Post by coryrc »

TaylorAlexander wrote: post #47
ipsum2 wrote: post #18

Does anyone have any suggestions on something that's a little higher quality, i.e. more torque and larger, like the size of a UR5 but cheaper than $30k? There's always seems to be a gap between "robot arm with dynamixels/off the shelf servos" and "research-grade arms".

I’m very happy with the mechanical design for my four axis brushless motor powered robot arm with integrated 3D printed planetary gearboxes. I have some hope of picking the project back up and better documenting it, though the CAD files explain a lot. For the last few years I’ve been working on my own brushless motor controller design and I think this year I will have that stable enough to go back to working on this…

Pretty neat! As a fellow motor controller designer, I worry you're wasting time reinventing the wheel in that regard, but I really like your project, I also want a farming robot.

Re: Low Cost Robot Arm

#55

Post by SirWart »

ipsum2 wrote: post #18

Does anyone have any suggestions on something that's a little higher quality, i.e. more torque and larger, like the size of a UR5 but cheaper than $30k? There's always seems to be a gap between "robot arm with dynamixels/off the shelf servos" and "research-grade arms".

There are a couple of arms commonly used in research around the $10k mark, namely the Franka Emika and UFACTORY xArm 6.

The ALOHA project uses the ViperX 300 6DoF, which is around $6500 but uses higher quality dynamixels with aluminum parts and bills itself as "research grade". I have one of these and I'd say it's expensive for what you get, but still cheaper than the "factory grade" robots. I will need a bimanual setup eventually and I'm probably going to get either an Emika or xArm since I'm already hitting the weight limits of the ViperX.

Re: Low Cost Robot Arm

#56

Post by otikik »

otikik wrote: post #52
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…

My impression is that the fastest/easiest way to do it would be putting all the pieces inside hopper with the selector at the bottom. Perhaps using compressed air to push the falling pieces into different containers as they fall. I believe there’s already something like that in produce factories, separating vegetables by state/size.

Oh look someone has already done something like that:

https://www.youtube.com/watch?v=04JkdHEX3Yk

Re: Low Cost Robot Arm

#57

Post by moffkalast »

alex_suzuki wrote: post #6

Anyone who finds this interesting might also like this one, it‘s not DIY – comes fully assembled: https://www.waveshare.com/roarm-m2-s.htm I have one and the build quality is really impressive for the price point.

There's also the 5-dof version that I've seriously considered buying at one point, but it's really hard to tell if the ROS 2 integration is any good: https://www.waveshare.com/product/robotics/roarm-m1.htm

A real shame there isn't a 6-dof one, since that's what you'd really need to grasp anything properly in the radius around the arm.

Re: Low Cost Robot Arm

#58

Post by etrautmann »

dr_kiszonka wrote: post #20
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

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.

Pasta is one of the few things you’re not supposed to stir while cooking?

Re: Low Cost Robot Arm

#59

Post by omeze »

Im currently waiting on the motors for this, but my bambu p1s printed out the parts with minimal stringing in like 90 mins. Really to try it out for cooking experiments

Re: Low Cost Robot Arm

#60

Post by TaylorAlexander »

coryrc wrote: post #54
TaylorAlexander wrote: post #47

Earlier quoted context omitted.

I’m very happy with the mechanical design for my four axis brushless motor powered robot arm with integrated 3D printed planetary gearboxes. I have some hope of picking the project back up and better documenting it, though the CAD files explain a lot. For the last few years I’ve been working on my own brushless motor controller design and I think this year I will have that stable enough to go back to working on this…

Pretty neat! As a fellow motor controller designer, I worry you're wasting time reinventing the wheel in that regard, but I really like your project, I also want a farming robot.

Thanks. I specifically want something that is designed in kicad, open source, and easy to manufacture at JLCPCB using parts already in stock there. Maybe there are more options now but two years ago when the Odrive we were using was discontinued and their new products got more closed source and more expensive, we didn’t have a lot of options. At this stage I’m very happy we’ve gone with our own design because we have so much flexibility on packaging and specification. Working with third party devices sucked.
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