Balls lodged under bridges??
 

After our team played at the KC regional this weekend one of the questions I have is:

Are there any reliable and simple methods to deal with balls under the bridges?

I saw robots with great shooters/ball launchers and fairly good bridge & balance manipulators.

Once balls went under a bridge things got interesting. What have you seen at other regionals?

Peggy
Bit by Bit 4-H Robotics/FIRST FRC Team #3784

2012 winners of GKC Regional thanks to Team 16 and Team 1986
2011 winners with Team 525 and Team 1730 @ GKC Regional
2011 High seed rookies @ GKC Regional
2011 Gracious Professionalism @ GKC Regional

Re: Balls lodged under bridges??
 

I attended the BAE Systems GSR regional in New Hampshire. We saw balls get under the bridge and teams lose balance points because of it. I think a simple sweeping bar attached to the front of the robot should do it. Of course this is my first year (pardon the pun) so........

Re: Balls lodged under bridges??
 

The problem with a sweeping bar is the 14" appendage rule. There needs to be a change to the field design. The ramps that were added under the bridge after week 0 do absolutely nothing. One idea I had was adding an accordion style skirt under the bridges. They would be inset a bit so as not to interfere with robots while the bridges were down.

I really think the GDC or whoever does field design needs to look at this and address it as a massive problem with the game.

Re: Balls lodged under bridges??
 

Actually, if you watch this, you will notice that the ball deflector is designed to only work when the bridge is pushed the other way.

Re: Balls lodged under bridges??
 

I don't think that the maximum rule of 14" will be enough to sweep under the bridges.
Just tip the bridge away from your robot 1st & then the lexan will roll them out & away so ramp mounting can be initiated.

Re: Balls lodged under bridges??
 

Please avoid making duplicate threads and check for existing threads describing this issue to avoid parallel discussions and minimize forum clutter.

Re: Balls lodged under bridges??
 

What everybody is missing here is that this is real life. Nothing is perfect, things are always changing. Get used to it & flow with it & you will progress in life without too many hitches. Yes the balls get stuck under the ramp, but that is why teams have to rethink their strategy. Think to yourselves, is there a ball underneath? Will I need to tip the ramp away from our robot 1st? Don't bash FIRST because it's not a perfect game. Every game played has had variables. Embrace it & get creative with fun mixed in.

Re: Balls lodged under bridges??
 

I disagree. While the balls getting under the bridges are a pain, they pose the same problem to every team. I saw several different ways teams at KC removed them, and at least one time I saw a robot get up on the bridge even though there was a ball on their side of the bridge. It kind of hopped up in a couple of stages.

I think the bigger problem is knowing that the balls are there, and where they are. That's another engineering problem, and I expect to see some different ways to solve it by the time we get to the St. Louis regional in week 4.

There's also the non-engineering part of the problem. Such as spending too much time trying to remove a ball when there's a better alternative like going to the other side. There were also times where it really wasn't even necessary to use the bridge.

I'd hate to see the field changed at this point. All of the teams have the same problem. I'd much rather see FIRST address the problems associated with volunteer food (seriously -- no filet mignon & lobster?) and inspector compensation. Are we really supposed to believe that working with great teams of both students & mentors is all we get out of this?

Re: Balls lodged under bridges??
 

They don't exactly pose the same problem to every team though. There are situations where it is actually impossible to get a ball out from under the bridge, and it happens to only one team that match. That match could be a tie-breaker finalist match.

Re: Balls lodged under bridges??
 

I saw some teams try to get onto the bridge and get over the balls too. It is just one of those things that makes FIRST so much fun to participate in! If there is a ball under the bridge, well.... what will you do?

Re: Balls lodged under bridges??
 

The trick is that teams who lift the bridge are typically on the same side as the direction that the balls come out which means they hit the robots bumper and go right back under or are stopped right at the bottom of the lexan plates and still block the bridge. Our team has a full width pickup and we started to just ram the pickup under the bridge and clear all the balls out in a few seconds.

On idea is if you are on the same side as the balls lift the bridge and quickly drive back so the balls can roll out. Teams aren't giving the balls the time they need to roll out.

Re: Balls lodged under bridges??
 

Our bridge mechanism was only on the corner of our robot, so many times we just knocked the balls off the bridge from an angle without being directly behind it.

Re: Balls lodged under bridges??
 

You crush them with the bridge and keep going.

Video (Match 91): http://www.more.net/content/2012-qualification-matches

At 2:38 in the video you can see that 967 is dealing with a ball under the bridge. Eventually they give up and go to the other side where they knock a ball into the other side of the bridge as well. 1986 come to the original side and crushes the ball with the bridge while climbing on. We do have to stay towards that end to keep the ball from preventing 967 climbing on after us.

PS. This was the exciting match where all 6 robots end up balanced, 2 on each bridge. Blue has a 19 point lead when red completes the double balance to take a temporary lead. Blue counters with their own double balance (even though only a single was needed) for the victory. Meanwhile the co-op bridge is blocked on both ends by ball adding to the drama previously described.

Re: Balls lodged under bridges??
 

The field & the rules are the same for everyone. Bad Things happen; where on the spectrum of those things would you like to draw a line that says "change the rules after week one" is right thing to do?

Re: Balls lodged under bridges??
 

Watch team 231 put a ball under the red bridge. Then 2936 spends the next 10 seconds trying to get it out for the triple balance.

Re: Balls lodged under bridges??
 

This whole ball being stuck issue is something I wished FIRST would have either fixed or noted in an official update with warnings to teams on just how severe it is. Reading or hearing about it from others or even on CD, isnt something that all teams hear.

It doesnt matter if all teams have the same problem at any of the events.
Not all of the teams have the same solutions/designs to remedy the situation if it were to occur.

Re: Balls lodged under bridges??
 

At the Smoky Mountains Regional the referees alowed one member, from each alliance, to go to the side of the field and signal their teammates if there was a ball under the bridge.
I know this doesn't eliminate the ball but at least you know it's there.

Re: Balls lodged under bridges??
 

Legal? I think it is because the only rule about balls on the bridge is they can't aid in balancing right?

Re: Balls lodged under bridges??
 

This is the second time I've heard this on chiefdelphi (after the fact); however, no one on my team was ever told this. When was this decided, and why wasn't there some sort of drivers meeting to make sure everyone knew?

I can't complain too much about the results, but this could have been a game changer for my team, as we were largely a bridge bot.

Re: Balls lodged under bridges??
 

The refs went through the pits Saturday morning and told every team.

Re: Balls lodged under bridges??
 

[G14]
Strategies that use Basketballs to either aid or inhibit Balancing of any Bridge are not allowed.
Violation: Technical-Foul, and counting or discounting the affected Bridge as Balanced, as appropriate.

Re: Balls lodged under bridges??
 

Refs at events are able to do this? Then SMR teams had an advantage that teams at other events were not offered?

Re: Balls lodged under bridges??
 

We were not told. None of the mentors, pit crew, or drive team member was told about this.

Maybe they saw someone standing outside the pit, assumed they were on our team, and told them, but it never made it to my team.

Re: Balls lodged under bridges??
 

This issue can be game-changing or outright frustrating for alliances.

I hope by now, FIRST is notifying each of the subsequent regionals about what changes, if any, such as the extra person spotting balls trapped for teams, will be allowed and relayed to all teams.

If this was something that FIRST felt teams should figure out on their own to remedy in matches.....then they wouldnt have a rule against it as a strategy to prevent teams from balancing.

From what I witnessed during week 1 regionals, its bad enough for teams to get on and balance themselves on the bridge.:)

Re: Balls lodged under bridges??
 

FIRST will be addressing this issue shortly.
In the meantime, Tipping the bridge from the other side will usually dislodge these trolls.
It's up to the teams to figure this out and try to establish a protocol of "clearing the bridge" before attempting to balance.

Re: Balls lodged under bridges??
 

Per today's team update:
http://frc-manual.usfirst.org/TeamUpdates/0#term%20149

Re: Balls lodged under bridges??
 

I'm not trying to be snotty here, or pick on anyone, but of course not all teams have the same design. Everyone had to make choices about what their robot can do. Shooters are different, bridge manipulators have different capabilities (or aren't on the robot), etc. And thinking that there might be a reason to look under the far side of the bridge is another choice.

We have a little plastic mirror that came out of a baby crib toy on the front of the robot. Depending on how your camera is mounted you might be able to use that. I'm sure smarter people than I can come up with other methods.

It'll be interesting to see if the field change will help with the problem. And I'm also interested to see what teams do to look under the bridge.

Re: Balls lodged under bridges??
 

I doubt this will be allowed at future events. It should not have been allowed at this event and I doubt if Aidian was consulted. If such a change was made officially it would have been communicated to the other events going on as well, and it was not. Sometimes well meaning officials try and "make things better" by locally "adjusting" the rules. In reality, they just create a mess that has to be dealt with later, especially at a Week 1 event

The original design had the plastic ball deflectors about 2.5" off the ground at the center of the bridge, which gives a slope of about 4 degrees. The revised version flips the deflector over and increases the height of the deflector to about 7", increasing the slope to a little more than 10 degrees. That will require more than twice as much energy for the ball to roll up and get trapped. That should significantly reduce the number of balls being caught under the bridge, and make them want to leave more.

Re: Balls lodged under bridges??
 

We never brainstormed ideas on looking under the bridge as we assumed the bridge and its appendage would take care of the balls rolling out effectively.
The idea of a plastic mirror instead of mounting another camera is pretty clever and inexpensive.

Re: Balls lodged under bridges??
 

I don't think the rules should be changed. I was simply stating that it isn't the same issue for everyone.

Re: Balls lodged under bridges??
 

As a point of reference for those interested who have not had the opportunity to see "under" a bridge, I will attempt to post a shot I made during disassembly of a bridge. You can see the ball-clearing mechanism has already been extracted. It is on the floor beyond the frame. This picture makes it clearer how complicated balls under the bridges can get. If under one of the joists, a ball has more impact on bridge movement than if it is between them.