Best way to collect balls off the field?
 

This thread is started to discuss ideas for getting balls off the floor and into the robot.

Last year at Nationals, the Vex folks had these cool rubber flappy wheels, and they would just pull those small balls right up into the robot. Anyone working on a larger version of that? Maybe brushes like a street sweeper, or arms that come out and sweep side to side (kinda like those nasty gathering 'bots that picked up older robots for the scrap heap, in the animated movie Robots)? After all, we have 60 x 60 to play with once the game's on...

Don

Re: Best way to collect balls off the field?
 

if possible, find some pictures from 2002 and 2004 games, tons of ideas there

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possibly two cylinders with counter wound surgical tubing. they would spin inward

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I know I can think of one team that was VERY successful in 2004 with their robot that was basically a vacuum that took up all the balls on the field. I don't want to give it away because I don't want to ruin anyone's ideas.

Re: Best way to collect balls off the field?
 

[quote=SURVIVORfan44]I know I can think of one team that was VERY successful in 2004 with their robot that was basically a vacuum that took up all the balls on the field.


That's a very good idea, but is it possible to create a strong enough vacuum with the given compressor

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yeah but isnt there a rule about only 60 psi?

Re: Best way to collect balls off the field?
 

There are many different ways to accomplish this task. I wouldn't saythat there is one better way than another - we have done it different ways over the years, the main difference this year is the ball itself. In the past the balls were either inflated rubber or soccer type. We haven't had to collect squishy (is that is a word) type balls.
It can be done mind you, but the dynamics is different from past years.
One good thing is that you probably won't tip yourself over, getting them into the machine.

Re: Best way to collect balls off the field?
 

Ah, I so wish i was on a team again this year...I have so many good ideas :(

But my idea would be an opening like a woodchipper, with a fabric type roller (similar to 121 from 02) that brings the balls into the center of the bot where they are stored for expulsion!

Re: Best way to collect balls off the field?
 

Two years ago when we had to collect and score those kickballs?...well our team made a roller system to feed the balls into a hopper that was lined with mesh material as to let it expand as it filled up. We ended up doing very well and it was very efficient because we could suck up anything in our path and it rarely ever got jammed. They called us the "Laundry basket" robot, but our rollers were covered with a rubber material to grip the balls and the rollers went in a curved path to lead the balls into the hopper and the rollers also spun the other direction as to let the balls go back out the same way to score in the side goals.

Stephanie

Re: Best way to collect balls off the field?
 

Is this what you are referring to? .If so how did that work. I never saw it.

Re: Best way to collect balls off the field?
 

Yes, exactly...
It was basically just that "no-stick" fabric that you use in your cupboards, they sewed it together into two big loops, and ran the system via a FP motor at a fairly good clip that fed into their collector, it was fantastic

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I hope you meant "no-slip".

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haha, yes...yes non-slip fabric

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That was my idea exactly. Even down to the non slip cupboard fabric. I guess I'm not very innovative =). Too bad those skirts won't let you climb up the platform this year. Im sure you need wheels at the corners or slants on the front and back in order to score those 10 or 15 points for your alliance.

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How about a belt along the bottom of the robot, as the center of the robot gets 'stuck' on the top edge of the ramp, just power up the belt and !zoom!.

Thanks for the details - we were a rookie team last year, and so never got to see any of the ball pickerupper mechanisms developed.

The big blue belt at the leading edge of the robot is obviously intended to move balls upward - does the 'belt' closest to the center of the robot move too, or is it stationary. (It doesn't look like a loop). Also, what's the purpose of that white roller-like thingie at the middle of the belt - tension? or something else, too? And, just for clarity, where the belt hits the white roller, the belt is moving upward, right?

Thanks,
Don

Re: Best way to collect balls off the field?
 

Both belts were driven so the balls were sucked up. We used two FP's to drive each belt. The piece of pvc that runs the width was used as a tensioner to help squeeze the belts together and maintain contact with the balls. Feel free to ask any more questions at any time.

-Tom

best way to collect the balls
 

what do u think and why either wheels, tracks,ect. ect. and getting it up to the loader this should be intereting because many people think creatively and it is nice to see creativity even though ur team might not be using it on their robot what do u think


also another question "should u use a hopper of some sort also or not what other ways would u do to carry them or increase ur capacity"

and how to load them efficiently?

Re: best way to collect the balls
 

For ball collection:

I've really been stuck on using vertically mounted belts to grab the balls off the ground and drop them off in a hopper. wheels with poles(or whatever you call them) protruding could probably work as well. I don't know how many people of thought of this, but a big shovel could also double as a ball collector and storage. It may even be able to drop balls off as well.

I believe that being able to score in the centre goal will give alliances the edge needed to win. Because of this, I was thinking of incorporating the ball storage with the mechanism that feeds the ball firing device.

Re: best way to collect the balls
 

yes but feeding vertically also is feeding against gravity and it could slip on the balls surface. going up and cause some problems

Re: best way to collect the balls
 

look at bots from 2002 and 2004, tons of good ideas

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A few bots to look at as a starting point are team 121 and 233's from 2002 and team 33's from 2004. All had amazingly efficient ball collection and release mechanisms.

Re: Best way to collect balls off the field?
 

Here's a hint

-Andy A.

Re: best way to collect the balls
 

if you go for the center goal and have a large ball storage capacity, do you think it's worth it to be able to collect balls off of the ground?
i guess what i am asking is would it be more efficient to have your human player fill your bot with balls during the second period while on defense (or any time during the match for that matter)?
that would mean you have to win auto. though to be on defense. :)

Re: best way to collect the balls
 

IMHO (and I know there are people who will disgree with me), there won't be as many free balls on the ground as compared to games like 2002 and 2004. Rather most of the balls will be controlled by a robot. It's not hard to build a funnel bot and just have a human player continously dump balls into a hopper with the bot right next to the control station. The only balls that will be on the ground are accidental, be it the human player missed the bot or the bot missed the goal.

Plus, if there are any balls on the ground, you can be sure that another bot with a ground loader will be grabbing it too. Cutting down the number of balls that you can get to on the floor.

So while a ground collector would be an easy addition to the bot, I don't think there will be many free balls on the ground to make it worth the effort/money/time/weight.

Re: best way to collect the balls
 

How about throwing balls to the backbot during the defensive period? I see an immense strategic advantage if the backbot is left alone (all 3 offensive robots trying to score). If it can pick balls off the floor (the human players on defense throw all their balls to the backbot), it can plant itself in front of the platform, wait for the offensvie period and score in the centre goal unimpeded.

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Then it would seem that if the bot had some sort of backbaord or other guidance system, the HP can aim for the bot instead of just in the general vincinity, which makes the collection take a lot less time and effort.

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http://www.golfmachinery.com/collectors.htm

This looks pretty good, size it up and I think it'll work for this year too..

Tatsu

Re: Best way to collect balls off the field?
 

aka i belive 126's 1992 bot...

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I was actually thinking about a golf-ball styyle collector. However, I am worried that it might push the balls away instead of pick them up. Any ideas?

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Re: Best way to collect balls off the field?
 

Remember, the rules state your robot just needs to be off the carpet to score the bonus points. Whether or not you can get to the top of the ramp is totally up to you.

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It is sufficient for the balls to get "pinned" against the carpet by such a collector.

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try testing with wood models. I haven't visited my school in ages, so all my tests have been conducted with lego.

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that is a good idea very creative never thought of that good thinkin

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Yeah, I agree with that. I think that there will be many funnels that will be used this year. I can't wait to see what kinds of mechanisms will be used this year.

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Actually I believe the funnels will pose a problem with jamming.

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Personally, I have to agree, because if balls have to ability to bounce around, even a little bit, at some point some will find a way to get jammed. It is also probable that if there are two balls in the funnel at once, they can get stuck against each other in the "neck" of the funnel. So, some more things to take into account when designing these systems.

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I would personally recommend if you use a funnel idea would be to use a like actuator or stir stick sort of thing to keep the balls moving and put it to where it will be most effective where the balls are most likely to jam

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I would think that with a reasonable hopper load of balls, just the general jostling of the robot would be enough to know any jams loose.

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So are you syaing it will pick the ball up with a conveyor or will it just spin. Also what did team 121 us for the rollers for the conveyor belts?

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I would atleast have something moving the balls just to avoid anything from happening and it still would not loose that much energy from doing it. it is just to be on the safe side

Re: Best way to collect balls [off the field]?
 

FYI i merged multiple threads together that were the same idea to keep the discussion centralized.

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You'd think so, but the problem ends up being one of weight as well. Too many balls on top can wedge the lower ones quite effectively unless you design to avoid it.

Re: Best way to collect balls [off the field]?
 

I'm just thinking about those toys...that you push around. It has a clear dome, and when you push it around, some kind of mechanism tosses all the coloured balls around. I never owned one myself, so I don't know how it works. That might help stop the jamming. A stir stick is a really funny idea though. I'm just picturing a big wooden stick rotoating around, moving the balls around.

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I had been thinking of this exact idea and had that exact worry, but this is reasuring. I think it would be best to have the roller clearance from ground adjustable to some degree as to "fine tune" the mechanism, to ensure the "pinnage".

Re: Best way to collect balls [off the field]?
 

we were testing out some belt ideas in our gym, and the balls seemed just fine accidently getting stuck under the treadmill, so i think a carpet will definitly provide enough traction with only one top belt

Re: Best way to collect balls [off the field]?
 

A conveyer belt at a 45* Angle would be able to shuffle the balls into the bot if needed. I dont have any pictures it would be viable.