Team update 3/6/2012

[coldfusion1279]

Glad to see they made a change. In elimination matches, alliances were losing because there happened to be balls under their ramps and they could not get on; either intentionally placed by the opposing alliance, or balls just happened to roll under.

[Tetraman]

Originally Posted by Marc S.

I wasn't looking for first to say that team XXX is illegal, I was looking for the rule update/clarification that made the hanging mechanism (like the one on 118) illegal.

It's rule [G10]. It's been there since the start of the competition season.

Every regional from now on is going to have the team of Field Builders attempt to figure out their own ways of solving the problem with the basketballs now, which is a very good thing.

I wonder if it would have been smarter for the GDC to forego the ball ramp and instead allow teams to activate mechanisms further outside the frame perimeter and increase the size of the fender.

[PayneTrain]

General

The official Android App for the 2012 FRC Q&A system is now available

Just in time!
I honestly do like the apps, but you think techies in FIRST would go to Android before iOS.

[martin417]

Originally Posted by Retired Starman

...This will help some, but the polycarbonate just isn't rigid enough and will continue to sag down to the edge of the bridge. What would really help is some edge strip to hold the polycarbonate straight.

Dr. Bob

Chairman's Award is not about building the robot. Every team builds a robot.

I watched some of the webcasts as well as some youtube videos later on. It appears that you are correct in that the polycarb is not rigid enough. If you look closely at the bridges, the polycarb seems to lie flat on the floor for most of its length, so it has no slope. If they were to add a small aluminum angle to each side, oriented upwards, it would help immensely. Maybe the increase in initial slope will help. We will have to wait for week two.

[Cal578]

Originally Posted by Retired Starman

...This makes the angle of the ramp steeper and it will bet even steeper when the bridge is pushed down. ...

How does the ramp get steeper when the bridge is pushed down? It looks to me like the ramp is mounted to non-moving parts.

[Nate Laverdure]

Originally Posted by Cal578

How does the ramp get steeper when the bridge is pushed down?

I believe Starman is referring to the ball deflector when talks about the "ramp." That is, with this update, the ball deflector has been rotated so that it's at a steeper angle with respect to the floor.

EDIT: Er, nevermind... you already understood that. He's saying that when the bridge is pushed down, the underside of the bridge contacts the ball deflector and pushes it down as well.

[Cal578]

Originally Posted by Nate Laverdure

...when the bridge is pushed down, the underside of the bridge contacts the ball deflector and pushes it down as well.

I'm not sure the bridge is going to push the ramp (or ball deflector) down in such a way as to make it steeper. Even if it does, if there's a ball in there that hasn't come out yet, the ball will get stuck between the bridge and the ramp, no matter how steep the ramp is or how it might change.

My point is just that all the improvement of the new assembly comes from it being steeper while the bridge is up, hopefully getting balls out before the bridge comes down.

[martin417]

Originally Posted by Nate Laverdure

....He's saying that when the bridge is pushed down, the underside of the bridge contacts the ball deflector and pushes it down as well.

Actually, the ball deflectors are tied to the bridge with a length of small diameter wire rope. When the bridge is pushed down on one side, the other side is lifted up. Since the ball deflector is tied to it, the ball deflector on the high side is lifted also, increasing the angle. See this video: at about 52 seconds.

[Nate Laverdure]

Originally Posted by martin417

When the bridge is pushed down on one side, the other side is lifted up.

Ah, that makes more sense. Thanks!

[JamesCH95]

Originally Posted by martin417

I watched some of the webcasts as well as some youtube videos later on. It appears that you are correct in that the polycarb is not rigid enough. If you look closely at the bridges, the polycarb seems to lie flat on the floor for most of its length, so it has no slope. If they were to add a small aluminum angle to each side, oriented upwards, it would help immensely. Maybe the increase in initial slope will help. We will have to wait for week two.

Maybe for some teams, but the angle would be obliterated by robots like ours that can quite easily tip the bridge away and clean out balls from underneath it.

I think it would be very unfair to teams like mine who solved the original problem but would run a serious risk of 'damage to playing field' penalties if the field element design was changed radically.

We took the mentality that it was just another challenge to overcome and another feature to set our robot apart. I'll admit I'm a little disappointed with the change because it takes an advantage away from teams like ours that worked hard to have that extra capability.

/mild rant

[martin417]

Originally Posted by JamesCH95

Maybe for some teams, but the angle would be obliterated by robots like ours that can quite easily tip the bridge away and clean out balls from underneath it.

I think it would be very unfair to teams like mine who solved the original problem but would run a serious risk of 'damage to playing field' penalties if the field element design was changed radically.

We took the mentality that it was just another challenge to overcome and another feature to set our robot apart. I'll admit I'm a little disappointed with the change because it takes an advantage away from teams like ours that worked hard to have that extra capability.

/mild rant

Except that was not stated intent of the GDC. The Bridge was designed so that balls could be removed by pushing the bridge down on the opposite side. The bridge did not function as designed and published at the beginning of the season. The change was made to try to correct this flaw. Had the GDC not published the ball deflector as a means of ball clearing, both in the field drawings and the Field tour video, you might have a point.

[JamesCH95]

Originally Posted by martin417

Except that was not stated intent of the GDC. The Bridge was designed so that balls could be removed by pushing the bridge down on the opposite side. The bridge did not function as designed and published at the beginning of the season. The change was made to try to correct this flaw. Had the GDC not published the ball deflector as a means of ball clearing, both in the field drawings and the Field tour video, you might have a point.

What I saw at both the Week 0 and the Week 1 was balls that the ball deflector worked on balls that were stuck reasonably far under the bridge, as depicted in the field tour video. However, balls that were near the very end of the ramp would not roll out, as might be reasonably expected because the lexan is supposed to be taped down by its edge. Even with the change is still impossible to tip out balls that are only partly under the bridge.

It might be that some fields (and even different bridges on the same field) were setup slightly differently and therefore behaved differently and that you and I merely have different observations.

[Drivencrazy]

as might be reasonably expected because the lexan is supposed to be taped down by its edge.

At GKC I helped with field tear down and none of the ball ramps were taped down on their edge. When you tip the bridge up, the edge of the lexan moves from where it was when the bridge is balanced.

[JamesCH95]

Originally Posted by Drivencrazy

At GKC I helped with field tear down and none of the ball ramps were taped down on their edge. When you tip the bridge up, the edge of the lexan moves from where it was when the bridge is balanced.

Interesting. I noticed the taped-down lexan at the Nashua Week 0 and GSR Week 1. Clearly not all fields were setup the same.

[billbo911]

After watching a few practice rounds today, it looks like the modification to the ball deflector is working fairly well!

GOOD CALL GDC!
Thank You!