sphere bot

[Veselin Kolev]

Wouldn't it be the scariest thing ever, if you set your robot down on the playing field. And another team comes up. With a big ball. You ask, what is that?? They say, our robot. It emits a blue glow, their team color. It rolls. It rolls over things. Wouldn’t that be AWESOME?

I personally think it would be worthy of applause if a team makes a sphere bot that can roll over other robots. Come on, you can make up to a 30” sphere. I am just wondering if any team has made a sphere bot before, and if so how they accomplished it.

Making a 30” hollow sphere that is light and strong must be a pain in the… Yea, if you have any ideas on how to make a sphere bot, please feel free to post here.

A related topic:

If one were to make a sphere bot, it would probably need a polycarb shell on the outside and inside. So… how would on go about covering a sphere with curved polycarb?

I have a few ideas, like milling a giant mold and melting plastic into it. But that’s expensive. Also, one could make a curved piece of sheet metal, lay flat polycarb onto it, and heat it up so the polycarb forms to the curve. If anyone has done this before (making a polycarb sphere), any advice would be greatly appreciated.

Thanks,
Veselin Kolev

[Elgin Clock]

You can always buy a premade polycarb dome here:

http://www.globalplastics.ca/domes.htm

Yeah.. We talked about making/buying one of our freshman a hamster ball to run around Atlanta in when we were looking for covers for our dome and I stumbled upon this site.

We were gonna buy two of these size balls here that is covering the salad bar and attaching them together somehow

http://www.globalplastics.ca/micashop1.jpg


edit: Ok, back to the subject at hand - enough ranting.
As for bending polycarb, there are a few good ways to do it, and a million bad ways.
In 2002 we had a polycarb formed cover on our robot as seen HERE.
It wasn't a sphere, yet was as smooth as a baby's rear end.
I believe this was achieved by a length or heated up material of some kind that was in the shape of a bow. It was used to form the curves on the robot's cover, and the cover held up all year. (Remember, this was the year that our robot was attacked continually by soccer balls)
I regret not knowing what the actual material that was used to bend the polycarb on this robot's cover was, but maybe I will see it one of these days.
I know it was a very simple device, that was like maybe a heated filament of some sort, and the lexan was bent around the material.

[dlavery]

Originally Posted by Veselin Kolev

Wouldn't it be the scariest thing ever, if you set your robot down on the playing field. And another team comes up. With a big ball. You ask, what is that?? They say, our robot. It emits a blue glow, their team color. It rolls. It rolls over things. Wouldn’t that be AWESOME?

You mean like this? Okay, so this one has a yellow glow instead of blue, but close enough.



This particular version of the Tumbleweed rover is wind-driven. But there is another variation built by a former FIRST student that now works at Johnson Space Center in Houston that is made entirely of FIRST-legal parts, and is actuively driven/controlled.

-dave

[Wayne C.]

my guys have discussed the idea in the past -especially considering the times we got Gyrochips in the kits - but other than roll around we couldn't figure out how it would play the game.

See if you can find the old toy called the Bumble Ball- it may give you some ideas on how to make this thing walk around. There are a number of cat toys that work on similar acentric cams and such.

If you do decide to build one I would certainly love to see how you do it....

WC

[Ryan M.]

Originally Posted by Wayne C.

my guys have discussed the idea in the past -especially considering the times we got Gyrochips in the kits - but other than roll around we couldn't figure out how it would play the game.

Yeah, the idea is cool, but it would pretty much ruin the mobility of your robot if you were to put out any appendages to actually manipulate something in the game.

Thinking about it though, Stack Attach might have worked with this. If you could get some actual power.

[rocknthehawk]

that would be aweosme...actually just having a sphere bot would be awesome...if i was going to build one, i'd jsut use 1" square moly tubing and bend it to make a frame, and then just cover that in sheets of aluminium that have been run through an english wheel a abunch of times, or something like 22-gauge sheetmetal....but i have no idea how this would effect the weight issue

[lbridgwater]

This is Roboball, it was designed , built and tested within about 6 weeks. most components are FIRST legal though I had to swap out a few things in order to fit under my weight limit of about 20 Kg ( 44 lbs). First ran about this time last year. It is capable of about 20 mph and will run for about an hour before the motors over heat or the battery for the IFI EDU controller dies. The ball material is a 50 inch diameter big-ins ball similar to the ones that have been used in a few FIRST competitions in the past. the little green wheels are just there in case the pendulum arm impacts the ground while traveling over bumpy terrain. It is inflatable and yes can travel across water.

[Ryan M.]

That's awesome!

Question though... is it able to turn? It's hard to tell from the pictures. (Being only two. And I'm an idiot programmer nerd who ignores the peasants who build the robot. )

[lbridgwater]

Definately able to turn, the pendulum interal to the deveice is leaned over at any angle you want and it will cause the sphere to lean over as well and as long as it is traveling forward it will turn, much like a motorcycle when you lean. Similarly the ball can lean so far over that it places the metal disks on the sides of the ball onto the ground and literaly turn on a dime. Though its nearly unstable if you try and turn at full speed. Tends to make the ball flip over, always a fun thing to see.

[JoeXIII'007]

I've always thought about it, never have proposed it to my team, but I've thought about it.

Thinking about it though, Stack Attack might have worked with this. If you could get some actual power.

There is no 'might have' with a sphere bot and Stack Attack. It would have been a champion bot just for the defensive capability and manuverability. I can see it knocking stacks of boxes down by 'bowling' into them and becoming king of the hill by rolling on top another bot or just evading them.

On a side note, why did I instantly think Samus when I saw this thread?



Source: Nintendo.com

[Adam Y.]

http://downloads.solarbotics.com/PDF/kit6.pdf http://www.chiefdelphi.com/forums/sh...ighlight=robot
Oddly enough this has been talked about before. It just was in the chitchat forum. Of course the robot discussed there pushed the definition of robot to the extreme.

[Adam Y.]

Please excuse me double posting but I figured it would be better than starting another thread on the same topic. Aparently there is a patent on a spherical robot. It was really quite random on how I discovered it because I was searching for the person's name. If anyone actually recognizes the name then you probably would know why I was curious.
Shperical robot patent

[greencactus3]

i just noticed. if you can have the spherical robot folded at the start and it folds out so the starting height limit is a little below the centerline of the sphere, then as much as other teams push you (assuming other teams robots only push from below the height limit), then they will not be able to push you (well they would, but) if you have a high traction, you can roll right over them no problem. anyone understand what im trying to say? please rephrase this then.

[phrontist]

Originally Posted by greencactus3

i just noticed. if you can have the spherical robot folded at the start and it folds out so the starting height limit is a little below the centerline of the sphere, then as much as other teams push you (assuming other teams robots only push from below the height limit), then they will not be able to push you (well they would, but) if you have a high traction, you can roll right over them no problem. anyone understand what im trying to say? please rephrase this then.

How would you change the size of the sphere? If it were somehow inflateable, it seems too easy to pop. I can't see any other expansion method being robust enough to work consistently.

[Levin571]

Another idea commonly passed around before was the idea of the hoverbot which would be cool to see but i haven't looked in the rule book for a while to see if it would be allowed