Ball deflectors.....don't

[kjohnson]

Originally Posted by Bob Steele

I wonder what is going to happen when an alliance rolls balls under both sides of the opposing alliance bridge..so they cannot balance it.

I wonder if this will be a G25 violation?

Its a G14 violation:

Originally Posted by 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.

[Grim Tuesday]

Originally Posted by nukemknight

Its a G14 violation:

I think the question was if the balls were placed there inadvertently, but by the actions of an alliance.

I find it somewhat disturbing that this problem is being considered part of the challenge, when they went to specific lengths to assure us it wouldn't.

[kjohnson]

Originally Posted by Grim Tuesday

I think the question was if the balls were placed there inadvertently, but by the actions of an alliance.

I find it somewhat disturbing that this problem is being considered part of the challenge, when they went to specific lengths to assure us it wouldn't.

From the video: "Its there to help balls roll out from under the bridge."

I haven't seen or heard anywhere where FIRST has specifically said that balls wouldn't get stuck under the bridge. As seen in the video, the polycarb sheet lifts on one side when the other side of the bridge is pushed down. The weight of the bridge has to be removed from the top of the ball before it will roll out. From the field demo video that you linked, it looks to me like the bridge and polycarb sheet are behaving just as FIRST expected.

[AllenGregoryIV]

The field is working as designed, from my point of view that design was not clearly stated. Since the ball ramps aren't part of the low cost field there was a slim chance a team would discover this challenge on their own with out some hints from FIRST. They could have worded it "that the ball ramps allow balls to be removed when the bridge is tipped to the other side" and I think a lot more teams would have understood the challenge as FIRST intended it.

[BigJ]

Originally Posted by AllenGregoryIV

The field is working as designed, from my point of view that design was not clearly stated. Since the ball ramps aren't part of the low cost field there was a slim chance a team would discover this challenge on their own with out some hints from FIRST. They could have worded it "that the ball ramps allow balls to be removed when the bridge is tipped to the other side" and I think a lot more teams would have understood the challenge as FIRST intended it.

I think the "it wasn't on the low cost field!" argument was covered last week with 118's hanger.

I dunno. I feel like the issue would come up in design when discussing bridge interactions. "Would I ever want to pick the bridge up? What are the reasons?" etc.

[Nuttyman54]

Originally Posted by AllenGregoryIV

The field is working as designed, from my point of view that design was not clearly stated. Since the ball ramps aren't part of the low cost field there was a slim chance a team would discover this challenge on their own with out some hints from FIRST. They could have worded it "that the ball ramps allow balls to be removed when the bridge is tipped to the other side" and I think a lot more teams would have understood the challenge as FIRST intended it.

The problem here is that, even if that was clear, a scenario still exists where a ball can get stuck under either side, making it impossible to lift up and clear*.

Whether it's intentional or not, the fact of the matter is that it was represented to teams that a system was in place to keep balls from getting stuck under the bridges, and balls are still getting stuck under the bridges. I have yet to see any robots which can get on the bridge without lowering it or without the assistance of another robot**.

When you have something as basic to the game as a Coopertition bridge, which counts as a win, it should be doable by almost every team...but if balls get jammed, nobody's getting on that Coopertition bridge.

There are some things the GDC can rightfully say are "part of the challenge", such as the chains sometimes deflecting goals in 2006 and 2010, or popped tubes in 2007 and 2011. This should not be one of those, as it is a situation which prevents teams from being able to complete a major part of the game, by no fault of their own, and is happening it a large number of the matches.

*I have not played with a real bridge with balls stuck under it. It's possible that they will move enough that rocking the bridge will clear them, even though it can't be pushed down far enough to climb on to

**With the exception of 118's hanger mechanism, pending legality rulings. It's worth noting that 179 can hang from the bridge without climbing on it, but someone needs to get on it first for them to be able to balance by hanging, thus they would require the assistance of another robot (and another robot requires theirs).

[nikeairmancurry]

I have seen a robot get on the bridge with balls trapt under it. Tonight at Kettering's practice 33 did it a few times, but I do not believe they knew the balls were there due to the fact the were driving towards themselves.

[mathking]

From looking at a bunch of videos, it looks like lifting the bridge only a little bit will allow a trapped ball to roll free. So if your bridge manipulating device can both push up and pull down you should be able to wiggle trapped balls out if they are on both sides. Push the side you are on up to get that ball out. Then push it down and drive up, freeing the ball on the other side.

[pfreivald]

Many of the past eight years we have made a critical mistake of one kind or another, usually in terms of assuming some kind of nominal value wasn't nominal. Thus, we paid a lot of attention to the bridge "help"ing keep the balls from jamming underneath... ...which doesn't mean they won't.

With the 14" extension restriction, they do appear for the most part to make the balls accessible to robots with the appropriate mechanism to knock them out (and/or suck 'em in).

Instead of railing against the unfairness of it all, teams should be considering what they can do between now and their own events (or now and tomorrow's first match) to be able to clear balls from underneath the bridge.

------------

And on that note, from what I can tell watching Alamo and KC today, lifting the bridge doesn't seem to work more than maybe 50% of the time (or less), so another method might be desirable.

[Josh Goodman]

Pat's post is exactly how I interpreted it as well. The ball deflectors do keep the balls from jamming up near the pivot base of the bridge (where all the balls would go without them). The definition said it would help keep the balls from jamming....which it does. It never said anything about rolling them with grace out from under the bridge so your robot can sweep them up with ease.

With the right manipulator, the balls under the bridge are accessible to all teams. It might not have been as readable as "a mechanism to put balls into hoops", but it's clear many teams thought of this problem and built devices to compensate. In my mind, it's all part of the game.

[jlindquist74]

*hikes pants up a few inches above his waist*

Suggestion: Consider this a part of your engineering education.

If I had a nickel for every time a vendor's product didn't *quite* perform according to spec, or some library or application fell short of the claims in its documentation, or behaved in some odd way that got in the way of my efficiently-planned project or solution, I'd be long retired.

Sometimes you can get a vendor to fix what ails you. But often, there isn't enough time, enough money, enough material, or enough staffing to do it. (You may also not be a big enough customer/client to accommodate.) You will usually work around it as best you can, and move forward. Maybe you and the vendor can fix it for release 2, but business or market pressures say you gotta ship release 1 without that fix.

If you choose this for a profession, you will run into this a lot.

You might study other teams' designs--even if their robot design is radically different from yours, there may be an element you can adapt this weekend, or carry in to the next competition. Or maybe it will help you design workarounds next year, if you're an underclassman. Learning from others' work is half the fun, anyways...

[Ivan Helmrich]

In KC today, several matches saw balls under both sides of bridges. It turns out if the ball is near the end of the bridge, the thing has to be tipped all the way to the floor on the other side or the ball won't move.

I wouldn't complain about it as an impediment, it plays the same for all. If FIRST's goal is to make coopertition a cool thing for the crowd to see though, they missed the boat. The ball under the bridge seems to have a randomizing effect on how successful teams are. It is a very specific type of mechanism that can deal with it the way it is currently playing out.

Ivan

[Akash Rastogi]

Relevant- https://www.facebook.com/photo.php?f...type=1&theater

[Travis Hoffman]

Originally Posted by Josh Goodman

With the right manipulator

Tape measure grappling hooks.

[Kevin Sevcik]

Originally Posted by Travis Hoffman

Tape measure grappling hooks.

Stacked on top of other robots to start the match.