Team update 3/6/2012

[Joe G.]

http://frc-manual.usfirst.org/TeamUpdates/0

Week 1 Observations and Reactions

The 2012 FRC events have begun, and Week 1 was a great testament to the FRC community’s ability to respond to the challenge. The events went well, and we hope that the Week 1 participants had fun and valuable experiences. Congratulations to Week 1 teams and volunteers for contributing to Week 1 successes.

That said FRC Staff and Volunteers have reviewed issues and opportunities that manifested in Week 1 and, in the spirit of continuous improvement, share the major ones, and their reaction plans, below.

The Arena

At some events, there were more trapped Basketballs toward the lip of the Bridges than originally expected. To address the issue, we have made a minor change to the way the ball deflectors mount under the bridge. We expect this will greatly reduce, but not necessarily eliminate, the instances of Basketballs trapped under the Bridges. These modifications effectively leave the dynamics of the Bridge unchanged. For details, please see the modified drawings GE-12017 and GE-12064.

The Robot

Inspection

Week 1 Inspectors have shared the three most frequent issues at Week 1 events. We share them below as a heads up for future competitions.

Bumper construction and placement

Robots had Bumpers shorter than 8”, measured from the vertices of the Frame Perimeter. A ‘Bumper’ is made up of the plywood backing, pool noodles, cloth covering and fasteners. Soft fill at the ends of Bumpers does not contribute to minimum Bumper length. Reference Rules [R27], [R28] and [R31].

Bumper numbering

Robots had their team numbers displayed in more than 4 locations on their Bumpers. Reference Rule [R35].

Robots had numbers that were not white or outlined in white, or not properly sized. Reference Rule [R35].

Robots had team numbers split between Bumper segments. Reference Rule [R35] and GDC Q&A answers related to this rule.

Motors
Robots used motors that are not permitted, or modified motors in ways that are not permitted. Reference Rules [R48] and [R49].

DLink Wireless Bridge – Hardware Version

DLink has released a new version of the DAP-1522 wireless bridge hardware used on the Robots. The new hardware revision, Rev B, is legal for use in FRC events; however, is not programmable by the Radio Programming Kiosk at events.


If a team has a DAP1522 Rev B (which would only be if they purchased a wireless bridge on their own, all bridges shipped in Kits are Rev A), they will need to retrieve their WPA key from the FTA at the beginning of the event and configure their bridge manually. Due to this inconvenience and opportunity for error, FRC strongly recommends that teams use the Rev A version of the hardware if possible.


A user can easily tell the difference between the Rev A and Rev B hardware platforms. In addition to being noted on the box and the back of the device on a sticker, the front of the bridge is also visibly different. In the image below, the Rev B is the upper radio, with the Rev A below it.

General

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


Good luck to all teams in Week 2!

Glad to see that FIRST is addressing the balls trapped under bridges.

[Kevin Sevcik]

Potentially addressing, you mean. It'll be interesting to see how well this modification performs at Week 2 events. It might make things worse by causing balls to collect right at the edge of the bridge where they're hardest to squish and most likely to cause difficulties. The only advantage is that they'll be slightly easier to remove there.

[pfreivald]

Potentially addressing, you mean. It'll be interesting to see how well this modification performs at Week 2 events. It might make things worse by causing balls to collect right at the edge of the bridge where they're hardest to squish and most likely to cause difficulties. The only advantage is that they'll be slightly easier to remove there.

That's good for us, I guess -- but bad for teams without a deployable ball intake. :(

[Lil' Lavery]

Potentially addressing, you mean. It'll be interesting to see how well this modification performs at Week 2 events. It might make things worse by causing balls to collect right at the edge of the bridge where they're hardest to squish and most likely to cause difficulties. The only advantage is that they'll be slightly easier to remove there.

They are certainly addressing the issue. They are only potentially mitigating or rectifying the issue.

[Marc S.]

I noticed that they didn't address 118's hanging mechanism at all. I know the head ref at Alamo presented a statement but the GDC can't expect everyone to have heard that.

[Ryan Dognaux]

Potentially addressing, you mean. It'll be interesting to see how well this modification performs at Week 2 events. It might make things worse by causing balls to collect right at the edge of the bridge where they're hardest to squish and most likely to cause difficulties. The only advantage is that they'll be slightly easier to remove there.

After looking at the modified field drawings, I definitely think this will improve things during week 2. The angle of the polycarbonate piece is greatly increased. Hopefully balls will, at worst, remain at the edge of the polycarbonate, allowing teams to simply push the balls out of the way with their drive train or intake them into their robot. Teams seemed to have the most problems during week 1 when the balls would escape the reach of most team's intakes or appendages under the bridge.

[GoSparx]

Potentially addressing, you mean. It'll be interesting to see how well this modification performs at Week 2 events. It might make things worse by causing balls to collect right at the edge of the bridge where they're hardest to squish and most likely to cause difficulties. The only advantage is that they'll be slightly easier to remove there.

No matter what, it seems, FIRST can never appease the masses.......

[DampRobot]

Was there really a problem with illegal motors being used? I know there was some confusion about not being able to use 540s on our team, but I would expect that teams would understand the motor restrictions...

[Tom Line]

I noticed that they didn't address 118's hanging mechanism at all. I know the head ref at Alamo presented a statement but the GDC can't expect everyone to have heard that.

The GDC will never state that XXX's robot is illegal to all the other teams. They state the rules, and will evaluate them on a case by case basis at the events.

[BrendanB]

I'm glad to see this change after competing in week 1. Balls under the bridge definitely added challenge to the game play but it was a challenge we all knew was coming. I think FIRST has done a great job with the bridges as there is only so much they can simulate (after competing at a FIRST scrimmage balls and bridges weren't a noticeable issue because bridge play was not as common) but they did a great job with the ramps to keep balls from getting stuck far back. This change should really improve the huge number of balls that don't have enough inertia to get stuck and come to rest at the bottom of the lexan plate just enough to interfere with the bridge.

Thanks FIRST!

[Hadi379]

I might be mistaken, but are the drawings conflicting in terms of how the ball ramp is mounted below the bridge? If you look at drawing GE-12017, compare the way the ball ramp is mounted in sheet 1 & 2. Which one is correct or am I not seeing something?

[thefro526]

I might be mistaken, but are the drawings conflicting in terms of how the ball ramp is mounted below the bridge? If you look at drawing GE-12017, compare the way the ball ramp is mounted in sheet 1 & 2. Which one is correct or am I not seeing something?

I noticed the same thing. If you look at the Rev Level, Sheet 1 is Rev A while sheets 2, 3 and 4 remain at their base revision. In this case Sheet 1 would take precedent over the others.

Also, for anyone who doesn't want to go through the hassle of opening up the field drawings, here is a screen shot of the drawing that shows the relevant changes. (Please excuse the size)

http://sphotos.xx.fbcdn.net/hphotos-ash4/425922_10150570882912693_601157692_9372007_1339113 396_n.jpg

[Marc S.]

The GDC will never state that XXX's robot is illegal to all the other teams. They state the rules, and will evaluate them on a case by case basis at the events.

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.

[ChrisH]

I might be mistaken, but are the drawings conflicting in terms of how the ball ramp is mounted below the bridge? If you look at drawing GE-12017, compare the way the ball ramp is mounted in sheet 1 & 2. Which one is correct or am I not seeing something?

The change is only shown on Sheet 1. They probably just forgot to update the view on Sheet 2. Easy to do when there are 123 sheets just for the game specific elements and you have less than a day to find a fix for a major problem and get it approved, documented, and published.

[Retired Starman]

I noticed the same thing. If you look at the Rev Level, Sheet 1 is Rev A while sheets 2, 3 and 4 remain at their base revision. In this case Sheet 1 would take precedent over the others.

Also, for anyone who doesn't want to go through the hassle of opening up the field drawings, here is a screen shot of the drawing that shows the relevant changes. (Please excuse the size)

http://sphotos.xx.fbcdn.net/hphotos-ash4/425922_10150570882912693_601157692_9372007_1339113 396_n.jpg

The change makes two improvements in the ramp. First, the polycarbonate ramp has been turned over and the aluminum angle, which was below the ramp has been removed. This makes the angle of the ramp steeper and it will bet even steeper when the bridge is pushed down. Look at GE-12064 to see that the aluminum angle has been removed. This drawing shows the polycarbonate upside down, guess FIRST didn't want to take time to flip it. GE-12017 page 1 shows the new orientation of the ramp. As before, the ramp is pulled up tight under the bridge.

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.

[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]

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]

...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]

...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]

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]

...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]

....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: (http://www.youtube.com/watch?v=-AMaqqmoLgQ&list=UUHA7zyPRS3VPDvl4ehss-zw&index=10&feature=plcp) at about 52 seconds.

[Nate Laverdure]

When the bridge is pushed down on one side, the other side is lifted up.
Ah, that makes more sense. Thanks!

[JamesCH95]

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]

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]

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]

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!

[Madison]

It looks as if the change to the bridge may break 179's robot. :(

[RogerR]

It looks as if the change to the bridge may break 179's robot. :(
how so?

It looks like they hang right from the edge, barely extending in a couple inches. Is the angle of the ball ramps that severe?