A well-designed robot can do any action a human can do. Whether this is an acrobatic performance, or just writing with a pen, there’s a robot out there for any single action a human can perform. This includes juggling, but never before has the human action of juggling been replicated at this scale. [Nathan] built a robot that can juggle seven balls simultaneously. That’s more balls in the air than any other juggling robot.
While the original plan was to build a low-cost version that could juggle balls by throwing them up in the air, this proved to be very difficult. Instead of giving up, [Nathan] simplified the problem by rolling the balls up a ramp. The entire build is documented in an imgur gallery, and there’s some interesting tech going on here. The 3D printed arms are controlled by beefy stepper motors running at 60V. To stop the balls from bouncing around in the arms, [Nathan] included and electromagnet to hold the balls in place for a fraction of a second during each cycle.
Juggling seven balls is amazing, but how about eight? This is the question every builder of a juggling robot will get, and it’s not quite as simple as adding another ball. The motion of juggling an even number of balls is completely different from juggling an odd number. That being said, [Nathan]’s robot does have four balls under its belt. It should probably get that looked at.
This isn’t [Nathan]’s first amazing 3D printed robot, and it probably won’t be the last, either: he recently built a Skittles sorting machine for the next time Van Halen comes to town. There’s an amazing amount of skill in all his projects, and he’s certainly an asset to the entire hackaday.io community.
If you look at the top of the ball field you can see that all the balls from each cup reach exactly the same height. That seems to me to be a high degree of precision to be transferring kinetic energy / momentum. That in itself may be very useful for other things.
Any small amount of deviation at the beginning of the ball path translates into a much larger deviation at the end of the path.
Now, if I did this I would make it fully vertical and cheat using magnets to control the balls. Maybe have one make an impossible move once every few minutes just to mess with people.
+1 for reality trolling
I’ve thought about that. That would actually be more impressive than my design. You would need one rare earth magnet per ball, and you would somehow have to move the magnets around in a juggling pattern by mechanically moving them. I’ve spent a decent amount of time trying to think about how to do that and it does not seem easy.
Holy crap! I just found this: https://www.youtube.com/watch?t=22&v=uL6e3co4Qqc
A crossing cam setup would be able to do the basic motion. Might also get away with a magnetic track for the crossing point and a bunch of robot arms. Overall though, it would be quite an impressive build!
Put the magnet on a chain/belt, would be my suggestion.
Very cool project. Preemptive “BOOO” to anyone who complains about the balls rolling on an incline.
There’s a robot out there for any single action a human can perform. Like solving captchas, performing surgery, doing CT scan interpretation, assembling aerospace gear, doing automobile repair, starting up businesses, working as dominatrices, practicing law, gestating a baby, creating new inventions, discovering new mathematical breakthroughs, deciding how best to improve quantum computing tech, etc. That sort of thing.
Hmm Not so sure about that.
To practice law a human must first have a frontal lobotomy so it’s debatable as to weather or not they’re human after that.
Hahahaha
I hope there’s a lot more to robot sex than mere dominatrices.
This is the most different marble machine I’ve seen in a while. I have no idea how you’d integrate this action with a more nearly conventional one, but I like the idea.
Is it considered juggling if it’s on a backboard or ramp? Kind of reminds me of this guy who “juggled” balls inside a inverted acrylic cone by rolling the ball around the incline of the cone. Without going into the physics of it, the balls do appear to be traveling slower over the entire path than it would be traveling through the air.
Don’t get me wrong. It is some interesting engineering. Would make for a pretty interesting game for example.
I’m just wondering if this is really considered uggling……
As a moderately good juggler (5 balls, 4 clubs, terrible at rings) I’m happy to call this juggling. Maybe not toss juggling and not contact juggling, somewhere in between. At a juggling convention I’ve seen a guy teaching people with an inclined slope (sadly I don’t have a link for it). It makes it easier for children or those who don’t have full mobility with their hands.
I’ve never seen juggling taught that way. Usually with small cloths.
I’ll have to check it out.
“And electromagnet” … Do some proof reading …
Well, not quite juggling as that would be 3D.
good jugglers keep it 2D, when teaching people you encourage them to keep the balls in a flat plane pararellel to yourself.
True, but part of the skill of juggling is keeping an inherently 3D activity in that 2D plane. Very cool build regardless. Satisfying to watch; kudo to the builder.
Could you juggle an even number of balls by having the hands at different heights to one another?