Beware of R16 your robot design may be too big.
 

R16 states that once the games starts a robot in its horizontal configuration can never be bigger than 80" More specifically all parts of your robot must fit within an 80" cylinder.

This is a pretty big rule once you think about it and do the math. If your robot is at maximum dimension ( 38x28 ) and you have your REQUIRED bumpers on, you can only reach a maximum of about 34" in front of your bot. All gripper designs that do not bring the ball inboard and reach around the entire ball would be illegal.

If you are planning to reach over the overpass while hurdling you better either start while underneath or not reach more than 3" past it. That includes your gripper.

Think about it, this rule is really quite limiting and if it's not reworded your gonna see a lot of people getting penalized for it.

I understand the intent, but if you have an arm that reaches in front of your bot basically at all, with a gripper that gets just beyond the radius of the ball then your very close to or already in violation of R16. Make sure you keep this in mind when designing your bots.

I think this will be one of the most broken rules this year and I really hope those that design within the rules aren't penalized for it by FIRST changing the rules late or refs not realizing how easy it is to break this rule and not calling it.

Re: Beware of R16 your robot design may be too big.
 

This is very restrictive for this year's game. Last year there was a 72x72" box, which works out to 102" on the diagonal. That's for a trivially thin robot though - in effect your arm could stick out about 38 or 40 inches in front of your robot. So this year, although the "grabbing target" of the game piece is nearly twice as large, you have about the same restriction on size.

Re: Beware of R16 your robot design may be too big.
 

You actually have something in the neighborhood or 7-8" less to grab a significantly larger and significantly heavier object, pretty much completely eliminates a simple arm for hurdling this year, unless your gripper is ridiculously short.

Re: Beware of R16 your robot design may be too big.
 

I dont think the bumpers count for this rule.

Re: Beware of R16 your robot design may be too big.
 

Could you quote that from the manual? I'm not seeing it... all I see is an exemption for <R11>.

Re: Beware of R16 your robot design may be too big.
 

I think this means that bumpers don't count towards it.

Edit: you're right, I don't see it talking about R16 in here, just R11, I just assumed. Lets see if they give us a rules update.

Re: Beware of R16 your robot design may be too big.
 

Bumpers do count when considering rule <R16>.

Re: Beware of R16 your robot design may be too big.
 

Remember this is a cylindrical measurement with no cap on how high up it goes. While you can't reach more than 80 inches outward, your upward reach is unlimited. According to R16, there are no height limits once the match has started.

Re: Beware of R16 your robot design may be too big.
 

I stand corrected... Luckily we still fit.

Re: Beware of R16 your robot design may be too big.
 

Your entire robot must fit into the 80 inch cylinder including any arms. If you go back to Stud Man Dans post, you will see that you would only be able to reach about 34 inches max in front of a robot that has the long dimension (38in) on the side of the robot. Seems like there will be a lot of forklifts/elevators this year.

Re: Beware of R16 your robot design may be too big.
 

That is crazy. I am going to have to do the math and draw things out to scale on this one.

thanks, Vivek

Re: Beware of R16 your robot design may be too big.
 

It is a really small volume once you start working with it. I've been sitting here for a bit today just playing with a spreadsheet I whipped up that determines our robot's arm's length extending from our robot. It just figures out the length sticking out (it's a double jointed arm) in the two worst-case scenarios, and from that, determines roughly how much play we have left in the envelope. Let me just say that there is very little play.

Re: Beware of R16 your robot design may be too big.
 

This rule is very, very restrictive to robots trying to hurdle. This will be THE rule that has the most attention during the first week. We plan on bringing a 80" cylinder to St. Louis to show our robot fits in the volumne at all times .... that is if we can make a mechanism that actually works AND fits in the 80". Right now we can do one or the other, but not both.

Re: Beware of R16 your robot design may be too big.
 

Somehow, I have faith in Paul's ability to crack this little problem and come up with a working solution that will - once again - knock our socks off. And if a bunch of folks with chickens on their shirts can do it... :)

-dave



.

Re: Beware of R16 your robot design may be too big.
 

So, bumpers do count as part of the robot in <R16>. But, consider the fact that bumpers are only about 3in thick, and that you only need 2/3 of the robot covered with bumpers. Then, if you have a 38x28 robot, you can leave the back of the robot without bumpers, and thus only gain 3in in the front, not a whole 6in.

Re: Beware of R16 your robot design may be too big.
 

Still doesn't take away from the fact that in the last 9 hours I've had two aneurysms and blacked 32 other times due to this stinking rule. I actually almost had it once. And because of the loss of about 3.14 years of my life due to the mental strain I can officially claim that we still don't like this rule. :-( lol

For those of you not worried about this issue, I implore you make sure you check your design in every position, this really is quite the issue. I do agree this is an extraordinarily restrictive rule and as far as I can remember quite possibly the most restrictive as far as an individual task goes since I've been in FIRST.

Ohhh and p.s. your robots in the animation broke R16 too Dave :-P J/k but seriously..... bah humbug

Re: Beware of R16 your robot design may be too big.
 

Paul, if space is tight in your trailer then please leave the 80" cylinder at home and bring your tools instead. :)

Re: Beware of R16 your robot design may be too big.
 

I'm now worried that y'all are worried. I've been having no trouble with the 80" circle so far. I haven't gotten to our manipulator yet, but everything seemed reasonable the last time I looked at it.

Re: Beware of R16 your robot design may be too big.
 

I want to see that cylinder. I'll bring the tools if it's a decision between them and the cylinder....

Re: Beware of R16 your robot design may be too big.
 

We found by drawing that an arm pivot has to be in the upper rear or front limit of the 5' tall 38" deep box. Even with that, the robot must wrap around the ball some to grab it. It came down to a choice of fewer laps and hurdle or faster without.

Besides, without the rule, it would be too simple:)

Re: Beware of R16 your robot design may be too big.
 

Thanks for the reminder to check this....looks ok for us.

2" per line on the graph paper, might want to double check the size...I drew the robot 28 x 38 plus 3" of bumper, we try to build a couple inches smaller to be safe, then it grows to max size at the last minute.

Re: Beware of R16 your robot design may be too big.
 

That's what I threw together in Solidworks the other day. The rectangle is a robot with full bumpers; the smaller circle is the ball. The angled lines represent a rudimentary claw.

Re: Beware of R16 your robot design may be too big.
 

I think this rule pretty much makes a flot-bot impossible.

Re: Beware of R16 your robot design may be too big.
 

Piece of Cake; Who says your robot has to be 38 long or rectangular?

Re: Beware of R16 your robot design may be too big.
 

who says you have to reach around the ball? :)

Re: Beware of R16 your robot design may be too big.
 

What you have there looks very similar to what I have in my drawings, but with that in mind unless you turn your claw you really can't reach in front of your bot, that to me is the annoying part. You've got a few inches of play, I'm confidant it can be done, just none of the ways I feel are all that simple. I guess you could build a very robust elevator near the front of the bot but then you have a significant amount of weight cantilevered on an elevator which in my experience, elevators really don't like that. I'm a kinematic linkage guy myself, but if to many linkages they can seem to be pretty wobbly which is no fun.

I wish FIRST had went about this a bit different, Its ok when they limit Engineering, but really hate when they limit design and creativity, I feel like they are kind of forcing our hand in a way. But I hope I'm completely wrong. I can't wait to see what everyone comes up with, Heck I can't wait to see what we come up with.

Re: Beware of R16 your robot design may be too big.
 

It said it must fit within an 80" cylinder, it never said where the center was.

so by the wording you could have a robot quite a bit larger than you thought, however this'll probably be fixed.

So yes, for now, it does not say that the center of the 'bot is the center of the cylinder, just that it has to fit IN the cylinder. Nifty circumvention, but I wouldn't bet on it.

Re: Beware of R16 your robot design may be too big.
 

Good catch on this one Dan. Hello from the Tokyo airport on the way to Singapore. Rather be with you guys building.

Re: Beware of R16 your robot design may be too big.
 

I'm not 100% sure what you mean by this, if you look at Madison's drawing it's pretty clear. The rule states that the robot at all times must fit in a 80" cylinder, no mater where the bot is located in the cylinder it must fit.

Re: Beware of R16 your robot design may be too big.
 

I think he perhaps means have the cylinder be angled to the plane of the ground. Some portion of your robot could extend rather far, but not close to the ground, and some portion near the ground could not extend very high. Though I think thats a bit of a 'lawyering' of the rule.

Re: Beware of R16 your robot design may be too big.
 

<R16> is pretty unambiguous about this. Horizontal dimension, upright cylinder... there's no way to work angles into this at all.

Re: Beware of R16 your robot design may be too big.
 

For those of you that think it is easy based on sketches ... I was there too until we actually prototyped something that is thick enough to be stiff enough and that is when we went "Ohhhhh .....".

If you use any rotational motion at all, be sure to check at the longest pont of projection. Our ball grabbing position is no problem, but the transitions are what are getting us. And no, we are not grabbing all the way around the ball.

Gary,

I guess I just refuse to make my drive geometry more complicated than it should be for a rule that looks like it was meant to prevent the "unfold and block" type defense.

All,

We have done many arms before and this one will absolutely be the most difficult (not complaining) simply due to the 80" rule.

I really just want to make sure everyone is aware of this very restrictive rule. I don't want the tape measure debacle of 2002 to happen again, because that will just irritate me and others who follow the rules from the start.

-Paul

Re: Beware of R16 your robot design may be too big.
 

Very good point!

Fortunately the section at the end of the arm need not be very thick, as it is under little load. The section that needs to be thick is near the robot.

Re: Beware of R16 your robot design may be too big.
 

Squirrel, take a second look at your sketch. As Paul said - it's not actually grabbing the ball that is the problem. It's when you open your gripper that it's going to bite you, depending on where your hinge point is.

Re: Beware of R16 your robot design may be too big.
 

Yes, I understand the problem, that's why I drew the sketch with the gripper open.

Re: Beware of R16 your robot design may be too big.
 

This is a general warning to all who try to hurdle (we are feverishly designing right now and I have bruises on my head from beating it against the table):

1. EVERY year MOST teams underestimate how hard it is to manipulate the game piece. This year will be no exception.

2. For our team, this is BY FAR the hardest year to manipulate the game piece due to the 80" rule (it is up there without the rule).

3. Please, please make sure you are within the 80" no matter what as I see this rule being strictly enforced all season.

Don't say you weren't warned ...

-Paul

P.S. - Thanks Lavery ... I will be sending you my hospital bill.

Re: Beware of R16 your robot design may be too big.
 

A maximum horizontal dimension of 80 inches and an 80 inch cylinder don't seem equivalent at all. For example, if my robot is an equilateral triangle with a side 80", then I have a maximum horizontal dimension of 80", but I don't fit into an 80" diameter cylinder.

Re: Beware of R16 your robot design may be too big.
 

I need to get more sleep...

Re: Beware of R16 your robot design may be too big.
 

I suspect that's what the GDC was thinking, but it's wrong. Note that the bisecting line of the equilateral triangle is 40" * sqrt(3) = 69".

Re: Beware of R16 your robot design may be too big.
 

heres a diagram. Maybe it will help clear things up.
DB

Re: Beware of R16 your robot design may be too big.
 

Uh, I'll take that bet Sean. Better sketch it out and rethink your response. Oops, I see David beat you to it.

I didn't pick up on the discrepancy in the rule StevenB, but you are correct. I just focused on the part in parentheses about fitting inside an 80 inch diameter circle thinking it was a clarification because it is more restrictive; I'll post a question on Q & A if noone else has. That makes a HUGE difference; it's the difference between the back corners being tangent to an 80 inch diameter circle as I've assumed or being the center of an 80 inch radius arc.

I just posted the question; we'll see. I'll be designing to the more restrictive requirement until I hear otherwise.

Re: Beware of R16 your robot design may be too big.
 

I don't have access to CAD (nor am I any good at using it). However, I broke out my handy dandy pen, paper and google (as I left my trusty TI-84 at school), and tried to tackle the size difference. I am notoriously bad at trig, however, so I could be completely off base, becuase I did not get the answer I thought I'd get. I didn't keep track of my work, but essentially, I drew a rectangle inside an 80 inch diameter circle, with the corners being located on the circle. I assumed a fix robot width of 28 inches, and tried to find how far forward once could extend. The answer I got was 74.9ish inches total. Subtracting the robot length (assumed to be 38") this leaves you with about 37" to play with.

If you're extending that far out for any length of time with anything hefty, I can't imagine you'd be very stable.

Can someone else do the math to either confirm or (more likely) tell me I'm way out in left field? It seems to me that if the situation is dire enough to warrant a Thunderchicken bashing his head, then I've probably screwed up my math.

Re: Beware of R16 your robot design may be too big.
 

with a cylinder whose center point is tangent to the ground and has a base perpendicular to the ground you can have a robot of INFINITE length! however it would only be able to go 40cm high and thats a semicircular shape

Re: Beware of R16 your robot design may be too big.
 

Here is something to look at and think about. Even though 80" can get very small very fast, that is a lot of space. Also, the further you go out, the hight center of gravity you will have, thus the ability to be pushed over easier.

Re: Beware of R16 your robot design may be too big.
 

What I'm gathering from Paul's post is that it is not the grabbing the ball that's the hard part. It's designing the arm to move the grabbed ball up in the air without extending out of your personal cylinder.

In case that doesn't make sense, stand in front of wall and extend your so that it's parallel to the floor, and move up to the wall. Then, move your arm so at a 45 degree angle down, and then to 45 degrees up. While those 45 degree positions may very well be in the cylinder, when the arm is parallel to the floor, it is not. That's where the design gets tricky, and the arm gets complicated to stay within that cylinder.

Re: Beware of R16 your robot design may be too big.
 

Time to think outside the box, but inside the cylinder.

Why does it have to be an arm? Why does it have to be a rotational joint? You can translate infinitely high. Why do you need something besides your robot's forward velocity to impart lateral motion to the ball? Forward initial velocity plus vertical force equals a trajectory.

Re: Beware of R16 your robot design may be too big.
 

We had to redesign 80% of our robot because we were about 3 inches out of the cylinder. We hope this rule will be STRICTLY enforced. We also hope that they DO NOT change this rule.

Re: Beware of R16 your robot design may be too big.
 

Yes, this rule does require alot of forethought.

Remember that when slicing horizontal sections, the size of the sphere gets smaller and smaller the farther you get from a centerline section, even though the center point stays in the same location.

Claw radial geometry works best if you keep the pivots as wide as possible.

And after grabbing the ball , you may want to consider doing something with it to get it closer to the robot.

Good Luck all - this one will hurt your brain, but it's all in a good way.

Mike

Re: Beware of R16 your robot design may be too big.
 

Yes in 2002 we decided against a mini-bot to stay within the entanglement rules. When we arrived at competition, every team with a mini-bot ruled the field.
If they let teams slide by on this cylinder issue, it would be extremely unfair to the teams that are currently racking their brains.

If FIRST is going to change the rule they should do now or make a statement that this rule will be strictly enforced. I know you can't make this statement for every rule in the manual, but this one is a make or break decision for teams.

Re: Beware of R16 your robot design may be too big.
 

Our team ended up recalculating the size of our chassis after reading this thread . We put the "just to be save" factor into our design. In other words, we discussed "worst case" scenario interpretation of this rule.

We ended up reducing the length of our chassis.

Thanks CD and the CD community. I believe that you saved us major headaches down the road.

Re: Beware of R16 your robot design may be too big.
 

It gets worse...I believe that this is without bumpers. Until someone like the GDC tells me otherwise, the bumpers do count as having to fit into the 80" circle. (Now, they don't have to be the full distance around, so you might be able to get away with these measurements, but I'd check them with bumpers.)

Re: Beware of R16 your robot design may be too big.
 

I (and probably a few others) have posted in the Q&A asking for clarification. (dbell, I used your triangle example, so thanks)

Re: Beware of R16 your robot design may be too big.
 

Bumpers (R08) are part of the robot (R13) and will be considered in the measurement if located on the robot where the 80" horizontal dimension (R16) maximizes. You can maximize the room available for your manipulator by leaving the bumpers off the opposite side. Right now you can do that without breaking any rules as long as any parts of your robot located within the bumper zone that are not covered by bumpers are within 10 degrees of vertical (R19). In addition, all bump to pass signals (G38) must be made with or against a standard bumper and inside the bumper zone. My guess is that when a team leaves the bumpers off to maximize the 80 inches, it will most likely be what becomes the rear of their robot. In order for another team to signal them to pass, the signaling team would only be able to signal if it had bumpers on the front of its' robot (doesn't make sense to signal from the side, you are all ready past them). At the same time, due to other types of manipulators, I can easily see teams that will leave bumpers off the front of their robots which will make it difficult to signal to pass a robot that does not have bumpers on its' rear. I realize that these are all design decisions and tradeoffs are necessary. You can build a succesful robot within these limits.

It seems like R16 (80" cylinder) and R08 (standard bumpers) are un-necessarily opposing eachother. R08 encourages teams to maximize their use of bumpers and R16 seems to discourage the use of bumpers and may make it more difficult to comply with signaling to pass. Another benefit to bumpers is the protection they provide. You could end up with a lot of exposed hard corners on the rear of many robots.

My ramblings have lead me to wonder whether or not R08, R13 or R16 should be modified to somehow leave standard bumpers out of the requirements of R16. Does anyone else see any wisdom in doing that? If a team has all ready decided to leave the bumpers off to maximize their 80 inches, what harm would changing the rules to allow them the opportunity to add bumpers be? I realize that there may be teams that designed to include bumpers and their manipulator to comply, but wouldn't they like to get another couple inches anyway?

Re: Beware of R16 your robot design may be too big.
 

As jgannon said earlier, the rule clearly does not allow this (80-inch-diameter upright cylinder).
I would be surprised if this is enforced at all, particularly the cylinder version. The only way to really enforce that would be to catch a robot suspected of breaking the volume, then after the match put the robot in a physical device to measure all the way around the circle - a refereeing nightmare.
Last year's 72" rule was similar, but in practice was only called on robots that had deployed ramps outside the home zone. I saw more than a few arms extending out of the box without penalty.
That said, I don't condone knowingly breaking the rule. GP, rather than the referees, will have to cover this one.

Re: Beware of R16 your robot design may be too big.
 

Don't EVEN get me started on that one. (Reference any of the dozen threads I have mentioned the mouse bot)

Re: Beware of R16 your robot design may be too big.
 

I am going to chalk this one up to a good engineering experience for the kids. We did not pay close enough attention to this, and it turns out one of our two possible lifter designs is an arm which will be about 2.5-3.5 inches too long when it lifts through horizontal. Since the arm design is completely done already, we will have a great ball remover (minus the grabber) if we can't get the other system to work!

On a side note, I do not think it will be that hard to referee this one. If you are designed to lift a ball, they will ask you to demonstrate it at inspection and they can measure then.

While it is giving me some increased blood pressure this weekend, I think this rule will make for some great fun as well.

Re: Beware of R16 your robot design may be too big.
 

Until you do it on the field though, there isn't any penalty. They can't fail your inspection because of it, any more than they would be able to fail you for being able to violently ram another robot. The most they could do is make a list of robots to watch.
It's possible that FIRST would make a rule saying that your robot has to be mechanically incapable of exceeding the size limit, but I find that unlikely.
I can see them pulling out tape measures, but as I mentioned above, that isn't equivalent to making sure to robot fits in a cylinder.

Re: Beware of R16 your robot design may be too big.
 

It would make refereeing a lot easier if the inspectors could determine if it is physically possible for a robot to exceed the 80" rule and mark it on the inspection sticker. If I know that a robot definitely can't break that rule, then I don't have to focus on supervising to see if it violates it.

Re: Beware of R16 your robot design may be too big.
 

And even if the robot is mechanically capable of leaving the 80" cylinder area, code can allow for mechanisms to be in the right position at all times. (ie: a double jointed arm)

The manual does not outline a process for checking this violation and it is not in the inspection checklist. As I see it now the rule is way to vague to be able to follow correctly. Hopefully they will respond in the Q&A or in the next team update.

Does anybody recall any penalties handed out for this rule last year?

Re: Beware of R16 your robot design may be too big.
 

I don't recall any being handed out at Great lakes.

For our part, after arriving at competition, we found that the process of deploying our gripper caused us to exceed the 72" rule albeit for less than 1 sec., so we tied up the gripper and in the name of GP (and not wanting to be the source of a penalty) didn't deploy it for the entire competition. We could still run defense, and climb on other bots, so we still did fine, and ended up with the Sportsmanship Award. Went home feeling good about ourselves and the competition.

We fixed it, and had fun at Kettering in the fall.

Steve

Re: Beware of R16 your robot design may be too big.
 

We are a Rookie Team this year and actually had a pretty good idea(at least I think so) to grab the ball with 2 rings but they will probably be outside the R16 rule so once again we're back to drawing board:(. Im really wondering how we could come up with a design that wouldn't cost us penalties for the new rule and so far I got nothing

Re: Beware of R16 your robot design may be too big.
 

see if you can contact the ball above and below, with some type of (safe) prongs about 26" apart, and tilt it up and back.

Re: Beware of R16 your robot design may be too big.
 

Certainly 72x72 was called last year, mostly for when a bot's ramps lowered prematurely.

Re: Beware of R16 your robot design may be too big.
 

Very true; it is not on the inspection checklist. But this is:
Team Compliance Statement
We, the Team Mentor and Team Captain, attest by our signing below, that our team’s robot was built after the 2008 Kickoff on January 5, 2008 and in accordance with all of the 2008 FRC rules, including all Fabrication Schedule rules (reference Section 8.3.3). We have conducted our own inspection and determined that our robot satisfies all of the 2008 FRC rules for robot design.

Last year when I noticed some a couples of team that looked like they were exceeding the allowable envelope, I pointed it out to them. They were not aware of it, and made the appropriate corrections to stay within the envelope. From my experience, no one in this competition wants to cheat or try to get away with an obvious violation of the rules that everyone else had followed, so usually it's a team that was unaware of the requirement or who misunderstood the requirement and they want to make it right when it is pointed out.

Re: Beware of R16 your robot design may be too big.
 

Our machine will be capable of exceeding the envelope, but will be programmed to stay within it, using potentiometers. We should be well within the cylinder.
However, I do worry about being over scrutinized, just because of the physical possibility.

Also, last year we were tipped over twice during the season by a collision, while scoring tubes. Since we were fully extended when we were hit. We were called for a 72" violation, while lying there helpless on our backs. (ouch!) :) I saw this happen to other teams as well. So if you get tipped you may be in violation of the cylinder rule.

And finally, I really hope that FIRST can make a definitive statement about how this rule will be enforced. Many teams are still in the early design stage and it will make a huge difference.

Re: Beware of R16 your robot design may be too big.
 

I believe that ALL parts of the robot within the bumper zone must be within 10 degrees of vertical. (And the rule is 2/3 of the perimeter is required to be bumpered.) I don't see where you get that you must have bumper protection to signal to pass, just that you must contact within the bumper zone or with a Trackball.

There are ways to maximize coverage and still maximize the amount of cylinder still available...

It wouldn't be a bad idea to have the bumpers excluded, but that makes the refs' job a bit harder. Bumpers can give a nice easy reference.

Yep. One or two teams at L.A. were measured post-match after accidental ramp deployment. At least one didn't pass.

Re: Beware of R16 your robot design may be too big.
 

I recall it happening at every competition I attended (VCU, Chesapeake, and Championship). The reason every time was a ramp deploying early and outside the home zone. I do not know of any time where it was called for an arm extending beyond the size limits.

Re: Beware of R16 your robot design may be too big.
 

It's there - I had to look to be sure. I'm not sure if the requirement to bump with or against a bumper was added in the revised G38 or not.

Re: Beware of R16 your robot design may be too big.
 

Ah, OK. I couldn't remember the bumper contact being a requirement--no metal on metal this year, I guess.

Re: Beware of R16 your robot design may be too big.
 

At least when bumping to pass per G38.

Per EricH: I believe that ALL parts of the robot within the bumper zone must be within 10 degrees of vertical. (And the rule is 2/3 of the perimeter is required to be bumpered.)

Correct, I just assumed that the bumpers would be vertical.


Per EricH: It wouldn't be a bad idea to have the bumpers excluded, but that makes the refs' job a bit harder. Bumpers can give a nice easy reference.

Maybe it would make the job easier since the bumpers typically are not attached at weigh-in/sizing. The inspectors could make this determination before the robot ever hits the track. I could easily see two vertical poles 80 inches apart with the robot on a flat cart. The team would to have physically move anything that goes beyond the starting envelope through its full range of motion. If at anytime the robot and manipulator or whatever can not pass between the post the robot it is not constructed "in accordance with all of the 2008 FRC rules" (quote from Inspection Checklist) and would not pass inspection. You would not have to attach your bumpers which are usually off the robot at this time to prove compliance with R16. It almost makes R16 obsolete. However, if you were using more than 80 inches of your infinite height in the playing configuration and tipped over before retracting you could still get the penalty on the field. That is the only time the refs would have to worry about R16. The top of the overpass will be approximately 80", within an inch or two anyway, and could easily be used as a visual reference when a robot is tipping (i.e. was it taller than the overpass when it fell or not) and my guess is that near the overpass is where most teams will be going higher than 80 inches to begin with. I could see that this would become a pain if you have to power up your robot to have it move through the range of motions during weigh-in. However, for those teams that are using programing vs hard stops to limit motion it would be an ideal time to prove out their software.

Per GaryV: It's there - I had to look to be sure. I'm not sure if the requirement to bump with or against a bumper was added in the revised G38 or not.

They only added: during teleoperated period, in revision #2

Re: Beware of R16 your robot design may be too big.
 

Yup, quite often, too.

It was far more obvious that I would imagine R16 violations to be, this year.

Re: Beware of R16 your robot design may be too big.
 

ATTENTION!!! New interpretation of R16 posted in Q&A responses, discussed here

Re: Beware of R16 your robot design may be too big.
 

I know that this was called a number of times. One that sticks in my mind was 45 being flagged at IRI because their gripper got snagged on the rack, and while backing out they went nearly horizontal. I remember robots with long arms being flagged after tipping at regionals, too, and I expect that to continue this year if a team doesn't e-stop first.

Re: Beware of R16 your robot design may be too big.
 

Recognizing that IRI is not an official event and has it's own set of rules, but you recall correctly. Also Team 1 Juggernauts were called for their arm being extended outside the box after they fell over.

In this year's rules it is written that a robot cannot cause another robot to
be penalized. So in my opinion if one robot knocks another over and that robot is now outside the mythical cylinder, there should be no penalty.

Re: Beware of R16 your robot design may be too big.
 

I think you guys got called for the penalty at nationals last year for this didnt you? I didnt think it was a fair call because you were getting pushed and your robot was out of your hands during the time but yea, i think the refs are going to being something thats 80" so that any tall bot can be warned that they could go out of the box

Re: Beware of R16 your robot design may be too big.
 

I don't think this is a very enforceable rule...

Re: Beware of R16 your robot design may be too big.
 

I wouldn't take that mantra to heart when designing your bot there are enough irate Engineers/Designers/Caders out there that will make sure it gets enforced and I'm one of them lol. I'm pretty sure this rule and this rule alone is what woody meant by simplicity on the other side of complexity.

Re: Beware of R16 your robot design may be too big.
 

This is an interesting interpretation that I haven't heard before. I can envision some scenarios where a robot could violate <R16> due to contact with another robot and not be penalized. I wouldn't say that this is a blanket rule... even if the other team tipped you, breaking <R16> might have been avoidable (much in the same way that you could potentially avoid a clockwise crossing, even if you were bumped). There are going to be some very interesting judgment calls for the referees this year.

Re: Beware of R16 your robot design may be too big.
 

If, based on the explanation in the FIRST Q&A, the parenthetic example is NOT the rule.

The rule is the part of the sentence prior to the cylinder example.


Measured horizontally includes all orientations of the robot - upright and fallen over.

Some infractions during the game will be obvious (fallen over while fully extended) - while some will be very difficult to determine without replicating the exact orientation after the match.

While the geometry I have been working on, is capable of reaching beyond the 80 inches - we will not allow that to occur by limiting the rotation of the joints using pots and mechanical stops.

If you have a similar situation, would you demonstrate your maximum reach to the head ref during the practice matches - in order to avoid any issues later during the matches or would you be afraid to bring additional attention to your robot? Meaning, the ref then tells the other refs to "keep an eye on that one".

Mike

Re: Beware of R16 your robot design may be too big.
 

Mike,

Your robot would probably draw attention on the track anyway if it looks like it was approaching 80 inches. In that case, if the head ref. had prior knowledge he/she could immediately say, I looked at that robot in the pits and they demonstrated their hard stops and programing to me and it does not exceed 80 inches, let's move on. Getting a quick definative answer would probably end any suspicions on the spot. I would like to see a range of motion test done while being inspected. That way the only dimensional rule that the refs. would have to worry about would be when a robot tips over. Not sure how practical implementing a test like that would be though.

EDIT: In the pits or during the practice matches.

Re: Beware of R16 your robot design may be too big.
 

How about if it was enforced in the same way that the ball velocity rule was in 2006? Assume that everyone is following the rules, but if a referee has doubts as to whether a team is complying, they can request a demonstration before the robot is allowed to compete again. I'd restrict it to just refs being allowed to request this (as opposed to 2006, where anyone was allowed to complain), but this seems like a much more time-efficient way to examine only the borderline cases and flagrant violators.

Re: Beware of R16 your robot design may be too big.
 

The fact that a robot can stretch to over 80" doesn't mean they actually will. A team who knows they have a robot that in certain configurations could stretch over 80" will take pains so as to not do it. It may be because of the hardstops or control restraints imposed by teams such as 47, or because of the uncanny ability of certain drivers to never extend the arm to full length when it is horizontal, only when vertical or on an angle. Nonetheless, until a robot actually does extend over 80" there will be no penalty call to make.

Ah, but there was a radar gun or something similar in the pit inspection station where all teams had to demonstrate their shooter. The ref could ask for a remeasurement, just as he could on size or weight, at any time. But it was demonstrated at least once (provided the equipment was working).

The GDC could require a demonstration on horizontal size during inspection. However, that still doesn't mean the robot actually will extend that far while on the track.

Re: Beware of R16 your robot design may be too big.
 

but how do you plan on enforcing it?, are you going to run out on to the field with tape measures everytime your get suspicious about a bot?

Re: Beware of R16 your robot design may be too big.
 

bumpers only need to cover 2/3 of the robot, one can simply not put them in the front. i highly doubt u'll be hit from the front since all robots are moving counterclockwise. therefore, you have 38 inches of the robot plus 42 for an arm

Re: Beware of R16 your robot design may be too big.
 

That's how we enforced the 72" rule last year... I expect that we'll do the same again.

Re: Beware of R16 your robot design may be too big.
 

You forgot width in your calculations. The maximum dimension will likely be across the diagonal of your robot - including the side bumpers.

Re: Beware of R16 your robot design may be too big.
 

wait so this rule is fully extended diagonally wise and not length wise?? im not sure i understand

Re: Beware of R16 your robot design may be too big.
 

the rule says "While in the PLAYING CONFIGURATION, the ROBOT may expand up to a maximum horizontal dimension of 80 inches"

This robot is less than 80" from the center of the rear bumper, to the end of the arm.

But it is more than 80" from the corner of the bumper, to the end of the arm

This robot should not pass inspection, as I understand the rule.

(although the drawing here shows the "cylinder", not the actual measurement from the corner of the arm to the opposite corner of the bumper, which is the limiting dimension)

Re: Beware of R16 your robot design may be too big.
 

I printed your diagram and believe that the robot would be allowed. I marked the longest lenght I could get across the circle on a piece of paper and then compared that to the horizontal distance between opposite corners of the robot and manipulator. It appear to be the same, meaning that the corners were 80 inches appart. What happens when I do that is that center of the cylinder is centered between the two points you are measuring. The interpretation does not say that no other part of the robot can be outside of an 80" diameter cylinder when measuring. The measurement is point to point. To apply my understanding of the interpretation I think you should place the center of a 160" cylinder on any part of your robot, if any other part of your robot sticks out of that cylinder, you have violated the rule.

EDIT: My analysis assumes that the cylinder is 80" since that is the way most of the references to R16 have been in CD, that the robot must fit inside an 80" cylinder.

EDIT: Thinking way to hard about the diagram, NO, THE ROBOT WOULD NOT PASS, per written word the robot drawn is more that 80" between the corners and would not pass. However, visualizing a 160" cylinder would still hold as a better way to apply the 80" rule. Your diagram did give me the idea of the 160" cylinder.

Re: Beware of R16 your robot design may be too big.
 

The way i understand the rule is as follows and this the way i explained it to the team: If you were to place a 80" diameter coke can, with the bottom removed, over the robot, would the can sit entirely on the ground ground or would part of it sit on your robot. If it sits on the robot, then we are breaking the size rule. The thumbnail is question would only be legal if it was oriented so that it's largest length was 80" and no other part of the robot was outside of the cylinder.

Re: Beware of R16 your robot design may be too big.
 

You do know that the cylinder reference is a reference only, right? Yeah, it works, but the rule is 80" point to point. Easy test: Two posts, set 80" apart. Put robot between in all possible orientations that come close (e.g. arm out). If any can't fit, they need to be hard-stopped or programmed out.

Re: Beware of R16 your robot design may be too big.
 

Please take a look at the FIRST Q&A, especially this thread: http://forums.usfirst.org/showthread.php?t=8159

There is no "80 inch cylinder" rule. That was just an EXAMPLE of one shape that will pass.

The rule can be rephrased as this: if you were to project all points of the robot onto the ground (i.e. a horizontal plane), would there exist any two points which are more than 80 inches apart? If the answer is yes, then the robot is too big.

Re: Beware of R16 your robot design may be too big.
 

I AM SO WRONG! The diagram a few post up really messed with my brain. Either the 80" coke can or a 160" coke can with the center on any part of the robot do the same thing. The kids have a design that fits within the 80 inches, it would just be a little bit better if they could get another couple inches. There are plenty of suggested ways to maximize the 80", I am not looking for any more in response to this post. Thank You.

EDIT: Responce to ay2B, previous post, I was posting this while you were also posting, I have been there and done that, many, many times, my head officially hurts.

Re: Beware of R16 your robot design may be too big.
 

This is the most clear way I have heard it stated.... Any two points more than 80" apart? if so, fail (restating that was more for my own understanding than anything).

Re: Beware of R16 your robot design may be too big.
 

Adam, the rule says "While in the PLAYING CONFIGURATION, the ROBOT may expand up to a maximum horizontal dimension of 80 inches"

I think that the best way to say that is just like you said it: There cannot be any two points on the robot that are more than 80" apart (in a horizontal plane)

Here is a better drawing of a robot that is illegal, even though the arm extends less than 80" from the rear bumper measured straight on (and I apologize to you ALIBI for messing with your brain!)

Re: Beware of R16 your robot design may be too big.
 

I like this drawing a whole lot better. Aside from design changes, there just does not appear to to be any way to make 80 inches any longer than 80 inches. Did I just say that? What if we measured with nautical miles, oops, that would make it worse.

EDIT: Thank you Squirrel, but it was probably more my doing than yours..

Re: Beware of R16 your robot design may be too big.
 

See Q&A: http://forums.usfirst.org/showthread.php?t=8181

A robot that is physically capable of extending past 80" but does not do so during a match will not be penalized.

Re: Beware of R16 your robot design may be too big.
 

yes but you would want to cover the back of your robot especially well since you will be getting "gently bumped" quite a bit there.

-vivek

Re: Beware of R16 your robot design may be too big.
 

What do you mean by "If you are planning to reach over the overpass while hurdling you better either start while underneath or not reach more than 3" past it. That includes your gripper.":confused:

Re: Beware of R16 your robot design may be too big.
 

ALIBI stated "does not appear to to be any way to make 80 inches any longer than 80 inches."

Now if you just accelerate your robot to near the speed of light whilst measuring it in the earth's inertial frame...