Star Wars VII Soccer Ball Droid

All of these methods for balancing the head on top seem a bit too fiddly to work reliably. Would it be possible to use the split ball method so the head is attached, but turn using some sort of gyroscope?
 
All of these methods for balancing the head on top seem a bit too fiddly to work reliably. Would it be possible to use the split ball method so the head is attached, but turn using some sort of gyroscope?

The main challenge with the split ball, even if it works like a Segway, is stopping it tipping sideways - plus the distance between the two hemispheres where they touch the ground is very close for differential drive. Even with a large counter weight hanging in the bottom half of the base it's still going to wobble around a lot so it'll be very hard to reliably keep both 'wheels' on the ground at the same time.
 

i think we were going in the right direction with the Sphero, but their new Ollie model mounted inside a sphere sliced in half with a few cm gap to connect a rod to the head is the best option, and is what I am going to be attempting in my build. Going to have to check the specs, but installing a Qi charger as well would make it easier.

http://www.thinkgeek.com/product/hrsp/
 
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I'm unclear what was wrong with this idea that was suggested in post #41 - it seems to solve all the issues of building a mostly working replica (at least what we see in the trailer). Since the sphere is totally hollow it also allows scope to have opening panels and so on, provided they only open when they aren't facing directly up or down which is trivial to solve with tilt switches.

I'm pretty sure there'll be a toy version out by Christmas 2015 ;-)

https://www.youtube.com/watch?v=dr5xdpLL58A

Any thoughts?
This looks like a neat idea but the head in the Star Wars video is clearly not mounted like that. If you were to use that idea and still try to make it look like the SW video you would have to have such a small wheel base I think it would be super unstable. The one in your video has a really wide wheel base, for stability I'm sure. Also It gives the "head" a very static and smooth movement, where again the SW video bounces and looks more unstable. I know that bounce may not be realistic to replicate in our world.
 
This looks like a neat idea but the head in the Star Wars video is clearly not mounted like that. If you were to use that idea and still try to make it look like the SW video you would have to have such a small wheel base I think it would be super unstable. The one in your video has a really wide wheel base, for stability I'm sure. Also It gives the "head" a very static and smooth movement, where again the SW video bounces and looks more unstable. I know that bounce may not be realistic to replicate in our world.

I think the wheel base could be made smaller, so it's inside the dome - and that being almost the same proportions as the dome/sphere in the trailer. Of course you'd see the wheels sticking down at the edges, but this is unavoidable. Provided the wheels can grip the ball ok then it will work - the stability comes from the active balance/traction/motion, not the wideness of the wheelbase.

You could probably still 'bounce' a bit and it should catch itself and stabilise on landing (at least sometimes, maybe).

Ultimately there are few ways to reproduce the CGI in real life, but I think this is the one that would drive the easiest and be most stable, even if the proportions/look are slightly compromised. It will be interesting to see other attempts though ;-)
 
Also It gives the "head" a very static and smooth movement, where again the SW video bounces and looks more unstable. I know that bounce may not be realistic to replicate in our world.
Not so, take my idea, counter weight it appropriately then add a spring from a bobble head and there you go, you could even put a micro servo on microcontroller to make it turn it's head every few minutes.
 
Ultimately there are few ways to reproduce the CGI in real life, but I think this is the one that would drive the easiest and be most stable, even if the proportions/look are slightly compromised. It will be interesting to see other attempts though ;-)


Are we 100% sure that it is in fact a CGI character and not a practical effect. To be honest it looks more like a practical effect especially when you compare it to the CGI scene in the background and the look of the ship and speeder effects.
 
Are we 100% sure that it is in fact a CGI character and not a practical effect. To be honest it looks more like a practical effect especially when you compare it to the CGI scene in the background and the look of the ship and speeder effects.

Some of it could be practical. Somewhere I read that the ball ran on rails which were digitally removed later or just out of shot in other scenes.
 
Some of it could be practical. Somewhere I read that the ball ran on rails which were digitally removed later or just out of shot in other scenes.
In that case it has to be 100% practical. The chaotic movement of the bouncing head never felt like something that was programed, it was far too natural, probably was a rod straight through both halves of the ball with a similar set up to how I described into a track. Probably self propelled though, since with a rod straight through a gyro wouldn't be needed.
 
In that case it has to be 100% practical. The chaotic movement of the bouncing head never felt like something that was programed, it was far too natural, probably was a rod straight through both halves of the ball with a similar set up to how I described into a track. Probably self propelled though, since with a rod straight through a gyro wouldn't be needed.

Disagree completely - nothing is 100% practical these days ;-) There are some complex physics simulations out there that would make the bouncing trivial to CGI.
 
Disagree completely - nothing is 100% practical these days ;-) There are some complex physics simulations out there that would make the bouncing trivial to CGI.
True, but I think the CGI in that scene was to erase the tracks and to make the ball sections movement more fluid, and yes bouncing is not a hard thing to program into an algorithm, but it still behaves in a programed manner and can be noticed it you know what you are looking for. it is a hard thing to put into words what I am trying to convey, but I stand by my hypothesis that this is an almost completely practical effect.
 
I am pretty sure that everybody who's been working on that movie, iespecially JJ, knew about the problems with the R2 units on all sw episodes. A producer like KK would fire you if you'd suggest to make Rolypolybot a practical effect. ;)
 
I just did an experiment and put a gyroscope inside of a sphere to see if it can keep the sphere stable.

The answer is YES! However, there's a catch. A gyroscope with enough mass to keep the sphere upright also has enough gyroscopic procession to spin the sphere at a comically fast rate.

Now, you could also do a vertical gyroscope to counteract these effects...but honestly at that point you're getting more into a thesis project than a replica prop.

A Ballbot (with the three wheels inside of the head balancing) may be the least screen-accurate of the options...but is definitely the most possible.
 
Meanwhile, back in early 2008...

new_pet.png
 
My locomotion theory: The body has an internal structure around which the ball casing moves on ball bearings etc. which are powered to move the droid about (like the mouse in a ball idea)
The head is held in place by a magnet surrounded by 3BBs which run on the inside of the casing while the head itself has a similar magnet/3BBs which protrude slightly from the bottom of the domed head. The two magnets attract each other holding the head in relative position with body's internal structure and the BBs allow the ball's casing to pass between them.
This would allow the spherical body to be solid.
View attachment 410314

That would be spot on for how to build it practically. Use a tilt weight system inside the ball to control the locomotion. As to the Ball Head being one droid I would say no. Looks to me more like the head is the droid and he is using the ball as a faster transport system. Also the ball reminds me of the training sphere Obi-Wan uses to teach Luke on the way to Alderaan. With the ground noise it looks to be a bit bigger than a softball but not quite to a soccer ball.
 
Well, when I first saw this droid all I could think is how much crap was given over Artoo's boosters.....and, not really surprised that people would accept this over that.
 
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