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PAROL6 Desktop Robot Arm
- barkingcat 3y agoCool I'll try to build one.
- krasin 3y agoThe video of the robot arm in action: https://www.youtube.com/watch?v=PiBCbHtvbpE https://www.youtube.com/watch?v=PiBCbHtvbpE Very impressive repeatability and very smooth movement for a 3d printed arm.
- arlcode 3y agoInteresting project. I wonder how the rigidity holds up over time. Working at a robotics company, the mechanical engineers had to overcome quite some challenges to find a compromise between, precision, speed and repeatability. And that was with a metal frame.
- sgnelson 3y agoI imagine a lot of that will have to do with the 3d printed material used. If you're talking typical FDM style PLA, ABS, the creep on these can be pretty terrible. If you're talking something like carbon fiber reinforced nylon, it's probably a bit better. If you move to something like Markforged's fiber-strand reinforcement it'd get even better. And then there are the SLA/SLS solutions, like Formlabs "rigid" material, which I think would be a very interesting material to try for this. I think at the end of the day, you need to keep in mind this is an educational robot, not an industrial robot. If it can maintain 0.050" of repeatability, that would probably be good enough for a lot of use cases (but of course, that depends on your use case.)
- krasin 3y agoMy biggest concern is that they use screws over plastic as fasteners: https://github.com/PCrnjak/PAROL6-Desktop-robot-arm/blob/main/Building%20instructions.pdf https://github.com/PCrnjak/PAROL6-Desktop-robot-arm/blob/mai... Quote from the manual: > Screws are in this example M3 screws and holes are undersized to 2.7-2.8mm that means that when we screw in the screws we are tapping holes in 3D printed parts. > There are multiple benefits to this: > ● Connection is strongest compared to tapping holes with a tap or using brass inserts > ● It is simple and fast > ● No need to prepare the hole, it can be printed undersized > Cons are that you can’t disassemble it a lot of times. In case you feel screws slipping in the hole. Put some super glue in the hole and wait for it to cure. After that re tap the hole.
- invalidator 3y agoI've used this technique on several of my projects. The formed threads are strong and reliable. It cuts down assembly steps and BOM. The tight fit means the screws won't back out (like locktite or nylocks). The only downside is they can only be reassembled a few times before they start getting loose, at which point you can either add material (superglue), or just reprint the part. If you have something you want to reassemble frequently, use inserts. If you're putting it together once and intend to use it that way for a long time, threadforming works fine.
- krasin 3y ago> I've used this technique on several of my projects. Did they have any moving parts? Did they experience continuous vibrations and frequent mechanical shocks? For DIY robot arms, fasteners are very often the issue #1, if arms operated more than just for demo purposes.
- iancmceachern 3y agoJust print it and find out. If there is a problem put in heat set threaded inserts. I don't think it'll be a problem though
- krasin 3y ago> If there is a problem put in heat set threaded inserts You would be surprised how many screws will go lose after a a thousand of hours of operation, even in this case.
- iancmceachern 3y agoI'm a mechanical engineer, product designer and technical leader that has designed many products, some of which have been implanted in people and are in the Smithsonian, etc. I know screws can come out, that's why they make loctite. What I'm saying to you is to make sure something is an actual problem before saying it is. In this case, the fact that the screws are used as self tapping, the screws themselves create the threads, likely combats this. Like a nylock nut. This isn't what I would do for say, a surgical robotics system, but that's not what this is. If given the choice of having the design as is, or making it more expensive, more difficult to assemble, and less accessible. I'd choose it as it is. There are always tradeoffs. I believe the designer made the right ones here. Before saying they didn't, maybe build one.
- PCrnjak 3y agoI have been abusing it for 8 months straight and too be honest I was trying to break it. Software has a lot of safety features to not hit joint limits, speed limits, ESTOP is operational... Only problem is that robot has no brakes so during power loss it falls. I thought it will be fatal for robot to fall like that but it survived it multiple times. Only parts that brake are esthetics and covers. Also i thought that repetability will suffer under such abuse but it stayed the same. The clip on youtube is after 6 months of a lot of use.
- fudged71 3y agoIs a possible solution to the arm “falling” to mount it upside down?
- PCrnjak 3y agoBrakes will be added in later design
- arlcode 3y agoSounds very interesting. Maybe this is a project where I can put the random collection of components to use which lying around in my basement. Not exactly to spec but that's the spirit I think.
- sgnelson 3y agoI wonder how this compares to the AR4 robotic arm ( https://www.anninrobotics.com https://www.anninrobotics.com ). The AR4 isn't truly hardware open source, but my understanding is that it's software agnostic. My biggest question is the full cost for the PAROL6. Their BOM link is 404. I can build the AR4 completely for less than $2000, and for education, that's a very small price for a semi-useful, full 6 axis arm. (Currently, to give a comparison, one of my suppliers is offering an educational cobot solution for $40,000. Yes, it's truly "industrial," and is a complete self-contained solution, though it's only capable of 2kg if I recall correctly. This was what they were pushing for the educational market.) As someone who is trying to implement robotic training in education, with a budget that approaches zero, I just need something cheap that students can hack/break/fix without costing a fortune in maintenance costs. One of the cool thing about the AR4 is that it can come as a complete kit, either as 3d printable or aluminum frame. and they work with Steppers Online to provide the steppers and drivers as one package. If you work for a school system, this type of solution solves a lot of logistical issues. That said, if this thing is truly low cost, let's say under $1000, for it's capabilities, it could be a very nice project.
- nulld3v 3y agoThe BOM file is in the repo I think: https://github.com/PCrnjak/PAROL6-Desktop-robot-arm/blob/main/PAROL6_BOM_6_9_2023.pdf https://github.com/PCrnjak/PAROL6-Desktop-robot-arm/blob/mai... Looks like they forgot to update the link.
- deleted 3y ago[deleted]
- ilaksh 3y agoThe instructions detail everything including the exact screws/nuts needed. EXCEPT the most important parts, the actual motors! It doesn't give any specs or names or a thing for those. Incredible. Also the BOM info is gone.
- unwind 3y agoAnother poster mentioned the BOM link, it's 6 NEMA 17s of various torque ratings.
- PCrnjak 3y agoHi i am creator of PAROL6, the BOM link is fixed. Also about the bom it will soon be updated in more detail. My focus is now more on software and finishing touches on hardware to make it safe so some changes happen in BOM. That is why is seems "incomplete or rough"
- bitwize 3y agoSweet! An Armatron for adults!
- iancmceachern 3y agoI love the armatron. It was so many engineers first exposure to robotic systems, was affordable and get-able by regular people, and magically ran off on one single motor. I was just watching some YouTube videos on it and how well designed the mechanics of it are, so clever!
- mohn 3y agoI was researching the Armatron last weekend and was surprised to learn then about the single-motor operation. It's quite a complex system of linkages and transmissions [0] to enable the six degrees of freedom. I suppose that explains why the toy is so noisy. I had no idea that was how it worked, must not have taken mine apart when it broke or I outgrew it or whatever happened. [0] http://www.jeff-z.com/pinball/toys/armatron/armatron.html http://www.jeff-z.com/pinball/toys/armatron/armatron.html
- iancmceachern 3y agoTotally. It also highlights an interesting change in engineering and product development that has happoned in my lifetime. It used to be, when this Armatron was made, electronics and computers were magic and mechanical engineering, real complicated kind of mechanical stuff, was common and the slillset to do it was similarly common. In that world it makes sense to have the whole robot arm powered by one motor that constantly spins, with mechanical clutches and linkages deciding what moves when. That's because electronics and mechatronics like motors and encoders were still expensive and new. Now its the opposite. In general, if given the choice between a complicated mechanical solution and a "simple" electronic/computer solution we choose that. Simple is in quoted because modern electronics and computers are far from simple. The manufacturing of a modern semiconductor rivals the Manhattan project. But is seems simple because we can just buy it at best buy and program it to do things. You can easily find lots of engineers to do something with code or an arduino, but finding someone who can design a fly ball governer, or even know what that is and why it matters, is rare. Now days there are tons of cheap robot arms that have a servo motor for each joint, because servos are cheap and complex mechanics are not.
- janci 3y agoI would love having one capable of unloading the dishwasher.
- NavinF 3y agoI've thought about building a robot to do that, but I think it would be cheaper to buy 2 or 3 dishwashers and modify them for use as cupboards. One will always be open for loading dirty stuff and another will always be open for retrieving clean stuff. btw ultrasonic cleaners are like miniature dishwashers and having one near my office room is very convenient for cleaning hardware compared to using the full-size dishwasher in the kitchen. Only disadvantage is that it needs soundproofing
- janci 3y agoYeah, I came to the same conclusion: 2 dishwashers. But a robot arm would be much cooler.
- BizarroLand 3y agoJust put the ultrasonic actuators onto your sink basin, and have a dish rack built in to it as well. Fill with water & soap, insert dirty dishes. Then when you head out for work in the morning, turn it on. let it buzz for 30 minutes or so, and then have a separate actuator drain the dirty water, refill and drain a second time as a rinse, and then drain again to let dry. That would be what, $1200 in parts and a season of testing to make work?
- NavinF 3y agoHmm some potential problems: I don't like the idea of having the dirty dishes right next to the clean ones so this would require at least 2 sinks so one can be loaded throughout the day My desktop ultrasonic cleaner is so loud that I can't work in the same room. Transducers that can clean an entire sink (>10x volume) will likely be so loud that I can't work in the same building when it's running If anyone in the building works from home, the unit will have to be soundproofed on all sides. That's way harder for a sink that's built into the countertop
- hobofan 3y agoI tried to collect a rough overview of available robot arms a few years ago (with focus on low-cost/open-source ones).[0] If anyone has some pointers on other recent projects in the space, I'd love to hear about them! [0]: https://github.com/hobofan/collected-robotic-arms https://github.com/hobofan/collected-robotic-arms
- Svenstaro 3y agoAre you maintaining that list?
- hobofan 3y agoDepends on what you mean by that :D As one can see the last commits are a few years old, and in the issues there are a few robot arms that I haven't worked in yet, which I want to do soon. However, I'd largely attribute the lack of activity to me not actually seeing a lot of new robot arms popping up. If there are any I'm missing or resources where one might regularly find some, I'm eager to hear about them and add them to the list!
- Animats 3y agoThere are lots of low-end robot arms. I have a uArm, which is not very good, on my desk. Way too much slop. Repeatability maybe 2mm.
- PCrnjak 3y agoHi guys I am the creator of PAROL6 arm. I was not aware of this community so if you have any questions feel free to ask me here. Also new video is up explaining more things. https://www.youtube.com/watch?v=PiBCbHtvbpE&ab_channel=Sourcerobotics https://www.youtube.com/watch?v=PiBCbHtvbpE&ab_channel=Sourc... Also anyone interested in building/buying it can sign up on these 2 forms for more updates. You can sign up here for beta testers (there are a few spots left: https://forms.gle/sZqHVLPoMJxuVAyJ9 https://forms.gle/sZqHVLPoMJxuVAyJ9 This is general form for people interested in control boards, kits, or whole robots: https://forms.gle/XkSvStwnQxw1f8xL8 https://forms.gle/XkSvStwnQxw1f8xL8
- RobotToaster 3y agoDo you plan to publish the CAD and EDA source files?
- chillbill 3y agoRequiring a google account to fill in the form is annoying and weird…
- iancmceachern 3y agoWelcome to the future