
The Octo-Bouncer - spchampion2
https://electrondust.com/2020/03/01/the-octo-bouncer/
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ximeng
Five ball juggling robot:
[https://www.youtube.com/watch?v=9asDO_1A27U](https://www.youtube.com/watch?v=9asDO_1A27U)

Three ball juggling / devil stick robot:
[https://www.youtube.com/watch?v=pKJEbs64Y2o](https://www.youtube.com/watch?v=pKJEbs64Y2o)

Partner juggling:
[https://www.youtube.com/watch?v=83eGcht7IiI](https://www.youtube.com/watch?v=83eGcht7IiI)

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jcims
High speed rock paper scissors champ -
[https://youtu.be/3nxjjztQKtY](https://youtu.be/3nxjjztQKtY)

Ishikawa Komuro Labs had a bunch of crazy high speed robotic vision and
actuation system ~10 years ago.
[https://youtu.be/-KxjVlaLBmk?t=65](https://youtu.be/-KxjVlaLBmk?t=65) if you
watch the slow motion there's so much backlash in the system it's hard to
believe it works at all, but somehow they factor all of that in. Crazy stuff.

That said, for a little side project this is very cool. The simulation idea is
dope and the end result is fun to watch.

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basicplus2
Yeh.. the scissors paper rock 100% winning rate.. robot is cheating.. every
time its waiting till human has made a choice, easy to see in slow mo

Alternative is bunny carrot gun..

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Centigonal
That's what the robot is supposed to do - it explains that on the slide at the
beginning of the video.

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sitkack
Build one these but using something like micro mirrors [1], esp in
microgravity this could be used for mass transfer and sorting of fine powders.
The powders could be parked in clumps in an electroacoustic grid potential
(ultrasonic phased array).

[1]
[https://en.wikipedia.org/wiki/Digital_micromirror_device](https://en.wikipedia.org/wiki/Digital_micromirror_device)

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Wingman4l7
Sounds similar to some work NASA did with to "walk" lunar / Martian dust
simulants off of glass using electrostatics, intended for use in colony
habitat windows: [https://www.nasa.gov/content/scientists-developing-ways-
to-m...](https://www.nasa.gov/content/scientists-developing-ways-to-mitigate-
dust-problem-for-explorers)

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chasd00
this is a amazing! I'm working on a flight controller and vertical stability
system for a high power model rocket and it's so freaking hard. You have to be
an expert fabricator, electrical engineer, controls engineer, and software
engineer. You also have to have the drive and dedication to get it done. It
makes the webdev I get paid to do seem so trivial.

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philipkiely
This article is really cool structurally, beyond the content itself. What I
mean is that it's formatted somewhat like a programming tutorial (build X with
Y in Z minutes) except that it's perfectly readable to people like me with
very little hardware background. Most of the specific implementation details
are abstracted out into links. I think that this kind of writing can be very
effective for technical people trying to reach a broader but still technical
audience.

Regarding the content itself, I think it's really cool that the author made a
sound-absorbing box for the CNC machine, and I'm surprised that it is safe to
totally enclose the machine like that. After spending last summer working at a
3D printing company that makes metal printers, I wonder how a 3D printer would
compare to the CNC mill in terms of time to create that many small parts, I
imagine it would only take one print-wash-sinter cycle, under 48 hours, about
1/4 of the article's reported machine time. That said the CNC mill used was
very small.

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heisenzombie
The 3D printers you were using probably cost in the $100k-250k range. I think
you can get tiny bench-top mills like that for something like $200.

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marcinzm
And a CNC mill at a fraction of that $100k price point would probably be much
more than 4x faster (due to spindle power and liquid cooling of the parts).

edit: Also since it looks like 2d work you can also use a fiber laser to cut
it out which would probably be faster and less messy than a CNC but more
expensive of a machine.

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gpm
Mechanically this seems like something that could also be built out of lego
(technic). Instead working with metal it seems like everything needs to be
custom machined.

Is there a reason there aren't similar kits of metal components with regularly
drilled holes and so on that can just be put together in whatever way one
chooses?

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tlb
There are some kits, like Actobotics. Generic structural parts are inherently
heavier and less stiff than custom-designed ones, so they're not usually
suitable for high speed projects like this one.

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rkagerer
This is amazing! But based on the title I thought it would juggle 8 balls.

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donquichotte
"I basically ran my Benbox CNC 1310 (almost) nonstop for multiple weeks."

Wow. That's some serious dedication. What an excellent multi-disciplinary
project, congratulations!

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SubiculumCode
This needs to be an exhibit at the San Fran Exploratorium.

[https://www.exploratorium.edu/](https://www.exploratorium.edu/)

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MertsA
Why four servos instead of just three? You could still have a square surface
with three, just mount to the glass underneath and maybe have a frame on the
glass to provide the triangular mount points. That way each servo is truly
independent, right now you only have 3 distinct degrees of freedom anyways so
you've essentially made an "overdetermined system".

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3953584
Intuitively I would assume three servos would require more precision,
practically, even though theoretically it's no problem.

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MertsA
Well, no, it wouldn't take any extra precision. If anything, the current setup
takes more precision as you have to keep all servos in sync or it'll be
pushing one servo against the others. Right now you could unbolt one of the 4
servos that are on it and it would still work just fine. You wouldn't need to
reprogram anything, just having 3 working servos and one completely
disconnected would still keep it in the exact same position.

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jv22222
That is awesome work and an awesome article. If that was a commercially
available product for sale I would buy it, because, fun!

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Waterluvian
Watching what it can do, it feels like this is the perfect machine to run one
of those marble mazes.

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mewse-hn
This is incredibly impressive.

My only domain knowledge for this thing is building a 3d printer from scratch,
but the design and micro-manufacture of this thing, combined with the software
that allows it to do what it does, is jaw dropping. Great work!

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scary-size
Video of the machine and Windows app:
[https://youtu.be/lYyAMDYzJQM](https://youtu.be/lYyAMDYzJQM)

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tantalor
Why "Octo"?

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p1mrx
There are only 4 motors, so it's probably named after the octagon-shaped
opening in the frame.

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cdaringe
10/10 great work

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the_cat_kittles
id be curious to know more about the planetary reducers. did you just need
more precision? or torque? seems like servo motors would solve the second
issue.

