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Joe Johnson
01-28-2002, 06:08 AM
What do folks think of the new ruling regarding pushing on the lower edge of the upper deck of the goal with a wall that is 45 degrees or steeper (measured with the horizon)?

Seems to me a pretty significant ruling.

Prior to this you had to actually design a mechanism to get some of the weight of the goal on your wheels. Now all you need is a ramped wall about 17 inches off the ground.

It seems that FIRST is intent on making this a pusher's game.

For my part, I think there was already too much of a tilt toward brute force and pushing in particular. This tilts the scales even farther.

It is entirely possible that the winning solution is just a squarish pusher robot with 45 degree walls 17 inches off the ground.

I hope not, but it may be so.

As always, other thoughts are welcome...

Joe J.

Ken Leung
01-28-2002, 07:33 AM
I think at this point, most teams have their robot designed up to the point that it will be hard to add a 45 degree ramp 17" off the ground... Especially with so many goal robot this year without any good reason to be a tall robot... until now.

I guess all you have to do, is add a few structure piece that extend all the way up to 17" off the ground, and just add a small size ramp...

But it is really possible that the goal robots already have some sort of mechanism to lift one side of the goal slightly off the ground for more traction, and that the addition of a small ramp will be in the way of that mechanism.

Mean while, with a lot of robots lifting goals for more traction, that mean the opposite side of the goal will be pointing down onto the ground, and not an flat surface anymore. So the little ramp can't be that little anymore.

Bottom line, I think enough robots will be planning to lift goal(s) slightly for more traction that this ruling won't affect too much design out there. It just provide an easy way for teams (probably beginner teams and rookies) to add more traction onto their drive train. And I think most teams expected other teams to lift up those goals for traction anyway.

Not too big of a deal, I think. What do everyone else think?

Dr.Bot
01-28-2002, 09:16 AM
Where was this new rule posted? Not in team update #4.

Doesn't effect our design - but might have if published earlier.

Joe Johnson
01-28-2002, 01:14 PM
From Yahoo Message #571


> We have been flooded with questions regarding interaction with the
> goal. We have previously stated that we would allow a robot to
push
> on the vertical surface of the stainless steel edge around the
upper
> and lower plywood decks. We will also allow a robot to push on the
> lower surface (edge) of the stainless steel angle that surrounds
the
> upper plywood deck with a surface/device/material angled at 15
> degrees or more from the horizontal.
>
> This deviates from our initial thoughts. Caution is advised,
> however, because devices like this that damage the goal will be
> disallowed at the competition. FIRSTsnow




My mistake 15 degrees. I was very tired when I read the message the first time.

If they really mean 15 degrees with the horizon, then this is even a bigger deal. It will be quite easy for a team to lift the goal with a 15 degree wedge angle.

Curiouser and curiouser...

Joe J.

Joe Johnson
01-28-2002, 01:55 PM
I could not for the life of me understand how I thought 15 degrees was 45 degrees.

Now I have an explanation!

Unluckily for FIRST, I printed, but did not pick up from the printer the message about the 45 degree rule.

In the mean time, I went back to find the rule and learned that the rule was 15 degrees -- no biggie, it was early, I was tired.

OR MAYBE NOT ;-)

I have just gotten around to getting my print out.

It is a print out of message #566 -- NOT message #571 quote above by me.

It clearly states "45 Degrees"

But... there is no message #566 on the Yahoo site any more.

Hmmm....

Is this one for the X-files or what?

Joe J.

P.S. I actually think there is no real intent to cover up anything. I think that when FIRSTsnow got in this morning, the folks at FIRST engineering decided to change the rule (again). It had only been out for a few hours at that point (posted at 7:13pm on Sunday night), they probably figured nobody would even notice. They just reckoned without Dr. Joe looking over their shoulders ;-)

Ah well... no harm, no foul. JJ

Chris Hibner
01-28-2002, 02:33 PM
Originally posted by Ken Leung
Bottom line, I think enough robots will be planning to lift goal(s) slightly for more traction that this ruling won't affect too much design out there. It just provide an easy way for teams (probably beginner teams and rookies) to add more traction onto their drive train. And I think most teams expected other teams to lift up those goals for traction anyway.

Not too big of a deal, I think. What do everyone else think?

I think this rule change is a big problem (similar to the "Poor Man's Balance" rule of last year).

Teams that do a good job of designing a robot to conform to the original ruling should be rewarded for doing so. Now, every team can lift the goals with very little ingenuity. Teams that were only planning on pulling the goals closer to their robot can now throw on a ramp and Voila!, intant lifting. Meanwhile team 45 (just as an example - I have no idea what they're really doing) has spent the last three weeks trying to design a good mechanism to lift the goals. All of this effort to gain an advantage has now been negated because now anyone can use a simple ramp. If they had known this from the beginning, they might have put their design efforts in another area.

I'm all for a game that allows small inexperienced teams to have a role, but there should definitely be a difficult task that separates the good teams from the great teams.

-Chris

Joe Johnson
01-28-2002, 02:48 PM
I would relent on this one if they said 15 Degrees from VERTICAL not from horizontal.

Otherwise, I am with Chris on this one. Folks have put a LOT of effort into there robot by now. This changes the trade-offs significantly.

Had folks know that things would change they would have taken a different path.

Joe J.

kevinw
01-28-2002, 05:06 PM
I'm not opposed to this ruling because I think there needs to be a way to separate the good teams from the great teams. I'm opposed to this ruling because it's a significant change in the rules that will affect a significant amount of teams.

For example, take teams A and B.

Team A spends 3 weeks designing and building a monster drive-train, and figures they'll get a grasp on how to handle the goals when the drive train is done. If I recall correctly, FIRST even recommends that the drive train be designed first, and mentions that it is perhaps the most important part. It is not unreasonable to expect there are a great many teams that identify with Team A.

Team B recognizes that lifting the goals might be an advantage for traction. Team B spends 3 weeks designing a monster lifting mechanism, and figures they'll get a grasp on how to move the 'bot around when the lifting mechanism is done. Not too unreasonable for teams that have designed drive trains in the past that could perhaps meet this year's task. It is not unreasonable to expect there are also a great many teams that identify with Team B.

Now, this ruling tells Team A that there is a simple solution to gain traction via lifting the goals that was not allowed previously but is allowed now. Team A now has a tremendous robot, where prior to this ruling Team A would have had to rush to design any kind of robust lifting mechanism. This ruling also tells Team B that they wasted 4 weeks and their time would have been better spent thinking about how to pose questions to FIRST in order to get out of having to design a lifting mechanism.

If this ruling stands, I think it would be in every team's interest to designate one individual from their team to analyze the most complicated part of their robot's design, and then formulate questions to FIRST to get them to relax requirements well into the 6 week design/build period. It may not be graciously professional, but this is the message that I see being sent.

Dr.Bot
01-28-2002, 05:55 PM
Team C regards any change in the rules as a new opportunity. Since their design is simple, basic and strong, the will have no trouble adapting to the new rule or chosing to ignore it. Also they won't sit around crying about 'wasted time' and realize in the real world the rules change all the
the time and the word "FAIR" just isn't in the
dictionary.

Sorry to come on strong - but I think this forum is being run by lawyers and not engineers. Go cut some metal.

Paul Copioli
01-28-2002, 06:50 PM
I say adapt and overcome.

We are one of those teams that spent a great deal of time engineering the hitch & lift mechanism. Our design was complete last Friday (or so we thought), but we were 5 lbs overweight (approx.). We spent all weekend putting our robot on "body solutions" to try and shed weight. Since the new ruling, we have just found a great way to lose the weight (we still might use our other way). I say adapt and overcome. Yes, I think the ruling put teams less prepared than us in a better position to compete with us, but there are still some technical challenges with the wedge that will get you if you don't think about them. Anyway, the rule change is waht the rule change is.

-Paul

Andy Baker
01-29-2002, 12:11 AM
Originally posted by Chris Hibner

Meanwhile team 45 (just as an example - I have no idea what they're really doing) has spent the last three weeks trying to design a good mechanism to lift the goals. All of this effort to gain an advantage has now been negated because now anyone can use a simple ramp. If they had known this from the beginning, they might have put their design efforts in another area.

-Chris

No idea what we're doing? ha! Chris, you must've been watching our super-secret webcam the past day. You would've seen our team knocking our foreheads against our shop's wall.

We had this really sweet 3-goal-lifting system where the titanium grabbers only contacted the goal's pipe and flanges. This system loaded all the goals' 540# on our non-carpet-damaging tread system... but, alas... now that this ruling is out, all teams will be loading down their 'bots with all three goals by simply putting a small wedge under the upper platform. So, we are back to square one.

But, seriously...

I don't like this new ruling at all. This is similar to these other FIRST rulings and rule "changes":

'92: allowing teams to make their own pneumatic systems
'97: allowing teams to reach under another robot and tip them over
'98: increasing the ability for the human player to affect a match's outcome
'99: allowing (and not allowing) teams to shove each other while on and around the puck
'00: initially restricting teams from shoving opponents off of the pipe and then not ever calling a violation
'01: allowing a "poor man's balance" and allowing liberal use of timing belt for added wheel traction

Now, since FIRST has made this rule change, I can see a couple of things happen:
1. Many teams will simply construct a wedge which will go under the steel angle to lift the goal... but... they will not realize that this will produce a moment on their robot which will result in a robo-wheelie.
2. Some teams will use a compressable material (SPI legal rubber, whatever) to contact with the lower edge of the steel angle at an angle which they think is legal, but since the material will compress, then there will be no such 15 degree angle for them to be legal.

So... the teams who did the brainwork and prototyping to get a way to lift the goal by the pipe may still have an advantage. What FIRST needs to realize that this ruling made a game which was previously VERY hard to referee even more difficult.

Andy B.

Raul
01-29-2002, 09:15 AM
Oh well, I may as well throw in my 2 cents.

We realized that lifting the goal with the old rules was the "differentiator" this year and were also looking at a design to clamp the pipe and lift the goal. It was going to be more complex than I would like and would probably make it much more challenging to stay under the weight limit. We had a design but I was getting headaches trying to find a simpler, more elegant way to do it. Now I can throw away the design and hard thinking that went along with it. Oh well.

But, I accept this new ruling as a bonus that we will happily accept and find another way to differentiate our design. Life goes on.

In regards to it making it harder on the referees - I disagree. I think this rule makes it easier. Here is why. I Imagine with all the pushing and shoving that will occur that in many cases a goal will get wedged on top a robot frames. Also, the complex goal lifting mechanisms would have been harder to judge if they "accidently" or "purposely" made contact with the steel angle when grabbing or lifting..

Raul

kevinw
01-29-2002, 10:08 AM
When joining the FRCtech2002 group, there was an option to receive special notices. I just received a special notice from frcengineers indicating that the angle in question is 45 degrees. Not sure if this is outdated, but it's the only special notice I received on the issue... This is exactly what it said:

We have been flooded with questions regarding interaction with the
goal. We have previously stated that we would allow a robot to push
on the vertical surface of the stainless steel edge around the upper
and lower plywood decks. We will also allow a robot to push on the
lower surface (edge) of the stainless steel angle that surrounds the
upper plywood deck with a surface/device/material angled at 45
degrees or more from the horizontal.

This deviates from our initial thoughts. Caution is advised,
however, because devices like this that damage the goal will be
disallowed at the competition. FIRSTsnow

ChrisH
01-29-2002, 11:58 AM
Due to low transmission rates I usually just read the Digest version of the FRC group. However yesterday when I just happened to look in here I found out about the potential change so I looked it up. The messages refered to were there in all their glory.

HOWEVER they were NOT in the digest that was transmitted in the wee hours this morning.

So Raul, I think you may have to uncrumple that paper yet.

I expect they will go back to the original interpretation of the rules. Hopefully if they do so we will recieve a public apology and announcement. Otherwise there may be some team who radically changes their design and then finds themselves DQ'd if they use it. Just because they didn't notice the "correction by denial". ie "it's not there NOW so it's not official"

We could save some weight by altering our design to take advantage of the rule change, but we won't for several days at least. We have decided to wait and see how things settle out. We'd rather make the parts and not need them than change plans prematurely and get stuck.

Besides our weights guys are saying we may need ballast anyway:D

kacz100
01-29-2002, 09:42 PM
If you pick up the goal (the way you are talking about ie. wedge)you can only push it. Right? So if someone latched on to it and pulled it you would be, well, SOL! Right? or am i missing something?

Joe Johnson
01-29-2002, 10:38 PM
If you pick up the goal (the way you are talking about ie. wedge)you can only push it. Right? So if someone latched on to it and pulled it you would be, well, SOL! Right? or am i missing something?

Not if you latch onto it!

Hmmm...

Will they change it? Don't know....

...I am still waiting on a clear answer on whether and for how long we can make repairs/improvements/spares after the regional. To my mind this is a question that has been out there since early in week 1. We are now in Week4 and nothing...

Ah well. Place your bets while the ball is still in motion...

Joe J.

Paul Copioli
01-30-2002, 08:32 AM
My bet is that FIRST will apply the 72 hour rule to making replacements after a regional (Tuesday by 5:00pm). Odds 2:1

Any takers?


-Paul

Andrew Dahl
01-30-2002, 11:35 AM
according to GM 23 our bot can come up to a robot and push on the lower plywood platform with the edge of our robot


our frame is vertial (90 degrees) relative to the floor

o i
o i
o i
o i

lower goal edge frame of robot

t1his is legal-- correct?

or do we need this

o /
o /
o /
/
/

???

please help asap

email to adahl@ns.gemlink.com

Daishichimaru
01-30-2002, 10:31 PM
Woah, might want to clairify that, Dahl. I'm on the team and don't know what the heck you just asked.

Jeremy L
01-31-2002, 06:12 PM
that all depends on your wedge design, kacz100. personally, i have no idea what the "goal grabber" division of our team is doing, but who am i to say? you could just grab the goal instead of using the wedge and ignore the rule altogether...i thought this was supposed to be one of the simpler games?:rolleyes:

Jeff Waegelin
02-02-2002, 09:15 PM
We came up with the ramp idea early on in our design process, and were all set to build it when we heard that it was NOT possible. We scrambled to find a new solution, only to find out that it IS allowed now.

I think that a ramp is a simple solution, and can help out any team, rookie or veteran. It may not be the most complex solution, but coupled with a robust grabbing system, it can be a very effective solution.

CaptainPlaid
02-11-2002, 02:16 PM
The forum this year has been a double edged sword. You can get answers to your questions faster but many of those decisions are reversed later. Also, a problem I noticed is that the e-mail "digests" are not to reliable. I have probably not gotton about 5 of them out of the 42 or whatever they are up to now. I say go back to just the updates instead of clarifying the forum contradictions in the updates.