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PAROL6 Desktop Robot Arm

github.com

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Re: PAROL6 Desktop Robot Arm

#31

Post by PCrnjak »

sgnelson wrote: post #28
wigiv wrote: post #22

Earlier quoted context omitted.

Seems like an open-source/DIY or kit (requiring some assembly) for educational applications is great in the context of a class or project where building/fixing/upgrading the robot is the point, and where 3D printing is readily available. If the main purpose is for the robot to do something - the DIY approach is more likely to suffer issues that, without support, may discourage students because they're fussing with/fi…

You're completely right about the DIY vs. Industrial issue. And the reality is that I need both, a DIY solution to teach students "this is how they work, these are the fundamentals, this is how to fix them/change them/operate them." And I also need one that can be hooked up to other machines, and able to be a true industrial robot (not so much with weight capacity, but with reach), and be a true integrated system to…

That is basically why made this robot. During my high school days we were 30 students on ONE old mitsubishi robot that was pain to program and was dangerous. On collages it was "oh we have 2 40000 euro robots but they are too expensive for students". So in both world we were mostly on simulators and simulators suck. I started with faze4 robot that was financed by my college but it was too large robot and i did not write any good software for it. More impressive thing than mechanical part or PAROL6 is its software and GUI. It is made for easy programming, has build in scripting language, jog control, error logging... Also i plan to port all my robots to that software and in the future make it universal for any robot. So you get a PCB that can communicate with the PAROL6 software, configure your robot kinematics and you are up and running.

Re: PAROL6 Desktop Robot Arm

#32

Post by hadlock »

qingcharles wrote: post #15
RobotToaster wrote: post #12

Earlier quoted context omitted.

>The AR4 isn't truly hardware open source Being pedantic this isn't either, there's no CAD source files, only stl files. Hopefully that's just an oversight.

For someone that hasn't used a CAD package in 30 years, can you explain the importance of this for me? Is a STL like a JPG is to a RAW in a camera?

You would expect STEP files in an open source project. This allows you to change the motor interface to use locally available stepper motors, adapters, or other modifications. STL is an intermediary, "rendered" 3D STEP file, ready for conversion into final custom gcode assembled specifically for your machine and any accessories/user specific procedural steps/initiation procedure etc.

STEP is the sheet music, MP3 is the STL and the waveform is the gcode.

Re: PAROL6 Desktop Robot Arm

#33

Post by PCrnjak »

Vespasian wrote: post #4

Interesting 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.

I 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.

Re: PAROL6 Desktop Robot Arm

#34

Post by krasin »

invalidator wrote: post #25
krasin wrote: post #19

Earlier quoted context omitted.

My biggest concern is that they use screws over plastic as fasteners: 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…

I'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 re…

> 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.

Re: PAROL6 Desktop Robot Arm

#36

Post by iancmceachern »

krasin wrote: post #19
Vespasian wrote: post #4

Interesting 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.

My biggest concern is that they use screws over plastic as fasteners: 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…

If you like, you can always slightly modify the parts in CAD before printing or even after printing with a drill bit and then put one of those heat set threaded inserts in with a soldering iron. Not a big deal. Do what you want

Re: PAROL6 Desktop Robot Arm

#37

Post by iancmceachern »

krasin wrote: post #34
invalidator wrote: post #25

Earlier quoted context omitted.

I'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 re…

> 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.

Just 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

Re: PAROL6 Desktop Robot Arm

#39

Post by iancmceachern »

bitwize wrote: post #10

Sweet! An Armatron for adults!

I 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!

Re: PAROL6 Desktop Robot Arm

#40

Post by fudged71 »

PCrnjak wrote: post #33
Vespasian wrote: post #4

Interesting 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.

I 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…

Is a possible solution to the arm “falling” to mount it upside down?
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