2 sets of bumpers legal?
 

Our team colors have always been red and blue. This year we built 2 complete sets of bumpers for our robot. One red set and one blue set. We would like to be able to swap out the bumpers from match to match depending on if we are on the red alliance or blue alliance simply to match the alliance color (and the color of the trailer we are attached to). I am wondering if other teams have done this in the past and if it is legal. How would multiple sets of bumpers be viewed in the rules and during inspection? Would they be like batteries that you are allowed to swap in and out as desired or would they be considered alternate configurations of the robot? Is one set a spare or do both sets have to be weighed in at the same time and be less than 18lbs collectively? I have read the rules and can see it being called either way. Bumpers like batteries are not part of the robot weight and so I wouldn’t think they would be considered an alternate configuration, however, bumpers have their own weight restrictions and batteries do not. Our two sets of batteries will not make the 18lb limit collectively but each individual set do, of course. What rules would govern this situation?

Re: 2 sets of bumpers legal?
 

I think so but im not sure...i want dual bumpers lol

Re: 2 sets of bumpers legal?
 

Sounds like a Q&A question to me. Though I seem to remember hearing of teams doing this in the past.

Re: 2 sets of bumpers legal?
 

Answer #1: Go to Q&A.
Answer #2: It was fine last year (under last year's rules, which are not the same as this year's).
Answer #3: I would guess that they'd be illegal because they don't make weight together. Why do I say that? <R13> says that you have to weigh all possible configurations (of the robot) together.

Answer #4: Hi ho, hi ho, it's off to Q&A we go!

Re: 2 sets of bumpers legal?
 

but i thought bumpers dont coult for the weight....

Re: 2 sets of bumpers legal?
 

Bumpers are not part of the weight referenced in <R13> though. Additionally you don't have to weigh spare parts, just alternate configurations. I think would qualify as spare parts rather than different configurations.

Re: 2 sets of bumpers legal?
 

They don't. They have their own weight limit of 18 lbs. The question is whether <R13> applies only to the robot or applies to the robot and the bumpers independently.

Of course, then there was one team with two sets of bumpers who didn't pass inspection last year... but they had other issues with inspection.

Re: 2 sets of bumpers legal?
 

If you're referencing 1519, that's a completely different issue. Let's try and keep that issue apart from this one to avoid confusion.

Re: 2 sets of bumpers legal?
 

You're probably right. However, some of the Q&A rulings this year have been...well...surprising, to say the least. Note that the first and last answers I gave were suggestions to go to Q&A, primarily because there are valid points on both sides.

I'm hoping it's legal, but at the same time, I can see it not being legal.

Edit: Sean, part of the reason for that was the second set of bumpers, IIRC. However, we will leave that alone now.

1038 would be a better example.

Re: 2 sets of bumpers legal?
 

I have seen teams in the past switch out bumpers. for example... wildstang switched bumpers in the elimination rounds in 2006 if I recall. all i think you would have to do is weigh them both so the are both legal. Still i would got to Q&A to be sure. but like i said you should be fine.

Re: 2 sets of bumpers legal?
 

In 2006, bumpers weren't required. They could have run without them if they wanted. Still, Q&A.

Re: 2 sets of bumpers legal?
 

I'll ask a Q&A when I get back in town next week and can find our password to the Q&A forum. I was just curious if this has been done by others in the past. I can see it going either way. One set isn't really a spare set in this case since the plan would be to swap them from match to match. To me a spare is to REPLACE a broken part. Once the broken part is replaced with a spare the original part even if it is fixed can't be put back on the robot again right because that would be a way around the alternate configuration rules. They really aren't an alternate configuration in my my mind because they aren't like two different mechanisms that provide two different functionalities. They are identical other than color.

Re: 2 sets of bumpers legal?
 

Right they were not. we didn't like the idea of bumpers so our team decide not to put the on so we could have more kinetic energy with the robot.

Re: 2 sets of bumpers legal?
 

Provided the other set of bumpers was functionally identical (and I would argue that color has nothing to do with function when it comes to bumpers), I believe that these would be spare parts and so unrestricted.

But what I say means nothing...ask the Q&A.

Re: 2 sets of bumpers legal?
 

We were one of those teams over the last two compeition seasons (Rack-n-Roll and FIRST Overdrive) that had color changing bumpers. In both instances they were legal as long as each set was built to spec. But, with the all of the bumper issues this year, I would definantly check with Q&A.

We decided against this year because our graphics team wanted to make sure the bumpers fit into the color theme of the robot graphics, website, buttons, etc.

Re: 2 sets of bumpers legal?
 

As you are only using one set of bumpers at a time, there is no effect on overall robot weight during a match. I would expect the Q&A to agree that this is legal. However, each set of bumpers will still need to be inspected and weighed separately. Please check in with your lead inspector for the latest if the Q&A is not answered. If you showed me two different designs for the bumpers, i.e. they are not identical in form, function and weight, I would ask you to choose one.

Re: 2 sets of bumpers legal?
 

Thanks for the info Al. Your logic seems reasonable and would be what I was thinking when I told the team to build two sets. As an inspector how exact would you feel the weights of the two sets must be? Other than color the two sets were made as exactly the same as we could make them. Same lengths, materials, bolts arrangement, etc. but one set weighed 0.1 lb more than the other. I assume this may just be the accuracy of our scale or the variance in the density of the plywood on one set or the other or the number of staples, etc. Is 0.1 lb nit-picking or should we worry? I'm not asking for an official ruling just as a previous inspector would you accept or reject the second set that was 0.1 lb different if the offical Q&A comes back as you have stated above?

Re: 2 sets of bumpers legal?
 

0.1 lb seems kind of trivial as a difference. Humidity could make that much change if you were near 18 lbs. What I would be looking for was one set over 18 and the other set under 18. I could not allow either to be over 18 for obvious reasons. An inspector has to know why the difference. Simply having two colors of the same bumper should not make a difference. I know of many teams that have two sets, one for qualifying and one for elims.

Re: 2 sets of bumpers legal?
 

Thanks Al.

Re: 2 sets of bumpers legal?
 

(NOT an official opinion, but provided as a thought-provoker): Why are the two sets of bumpers different colors? If the different colors selected are purely arbitrary and make no practical difference when playing the game, then one might argue that the colors are purely decorative. As such, the two sets of bumpers could be argued to be functionally identical, and therefore spares for each other. However, if the bumper colors are repeatedly changed to correspond to the alliance assignment, then some would argue that they provide a tactical purpose (aiding identification of the robot) and are therefore functionally different. As functionally different parts that are used selectively based on conditions of a particular match, it could be further argued that they would fall under the constraints of Rule <R13>.

I would recommend posing a question to the official Q&A system on this one. The question might be posed in the context of the considerations discussed above.

-dave



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Re: 2 sets of bumpers legal?
 

Food for thought...
Would two color bumpers be any different than interchangeable lexan panels of different colors? What if the panels were red on one side and blue on the other with velcro fasteners?
Can I respectfully submit that bumper color on the robot in this year's game could provide very little advantage? (my early morning GDC wannabe is coming out again.)

Re: 2 sets of bumpers legal?
 

Even though it's a completely different matter and unrelated to the original question in this discussion, 1519's bumpers last year between both robot configurations were within the 15-pound weight limit. We had a set of of six bumpers (some of which were quite short) which altogether weighed less than 15 pounds. Only four of the six bumpers would be on the robot for any given match.

If you can make your two complete sets of bumpers together satisfy the weight limit (as well as all the other bumper requirements) I would think you should be fine.

However, the GDC took the exact opposite perspective last year, ruling that all the bumpers needed to be on the robot at one time.

Re: 2 sets of bumpers legal?
 

If it is unrelated to the original question, please do not extend the thread with posts. If you are interested in revisiting the previous ruling, please create a thread specifically to discuss that.

Thank you, Molten

Re: 2 sets of bumpers legal?
 

Did you read the rest of the post? It's pretty clearly related to the bumper discussion... :)

Re: 2 sets of bumpers legal?
 

Molten,

Sorry about that. As I was writing my earlier post, it started out on a tangent. However, as I revised my post before posting it, what I ended up with actually ended up being quite relevant. Yet, the post is founded on information from last year, which officially doesn't apply at all this year, as just because something was allowed (or not allowed) last year doesn't mean it will be the same way this year.

My post should have read as follows:


Even though this information is from last year (and thus doesn't have any official bearing on this year's rules), 1519's bumpers last year between both robot configurations were within the 15-pound weight limit. We had a set of of six bumpers (some of which were quite short) which altogether weighed less than 15 pounds. Only four of the six bumpers would be on the robot for any given match.

If you can make your two complete sets of bumpers together satisfy the weight limit (as well as all the other bumper requirements), my personal interpretation is that you should be fine.

However, the GDC took the exact opposite perspective last year, ruling that all the bumpers needed to be on the robot at one time.

Thus, if the GDC is being consistent with their reasoning from last year regarding the bumpers of the dual-configuration robot issue, then all of the bumpers of the set need to be on the robot for every round.

Re: 2 sets of bumpers legal?
 

That is, unless they second set of bumpers is functionally identical to the first set, so it can qualify as a spare part.

Re: 2 sets of bumpers legal?
 

Good point -- I hadn't thought of the second set of bumpers being considered a "spare part." That perspective then takes us back to the consideration that Dave Lavery raised above -- is the second set "physically and functionally identical" or is the color difference a "physical or functional difference"? Seems like if the different-colored bumpers are considered to be "physically and functionally identical" then they're okay; if not, no good...

Re: 2 sets of bumpers legal?
 

Wow, here is a perfect example of over-thinking/over scrutinizing the rules. Using two different colors for bumpers is a perfectly logical thing to do since the bumpers on the trailer will reflect the alliance color, and matching the bot bumpers to the trailer bumpers will help BOTH alliances determine what side you are on. If we had decided to do this, it would never have occurred to us that there was any possibility that this would be illegal, or even questionable. It seems obvious to me, even now, that there is no rule that would prohibit this. As for functionally different, the function of the bumper is to protect the bots and field, color has no impact on this function. I don't see a situation where this practice could be seen as against any rule.

Re: 2 sets of bumpers legal?
 

Questions submitted to the Q&A with respect to all of the thoughts and concerns mentioned in this thread. No we wait and see...

Re: 2 sets of bumpers legal?
 

Philosophical question: can robot parts have official psychological functions? As the rules are written (inferring intent), I don't think so.

Re: 2 sets of bumpers legal?
 

well i doubt it there doesn't seem to be a reason for it to be illegal it's like making a quick change before competition what's wrong with before matches it's not like we're swapping parts up for something illegal and ridiculous like a handsaw or rockets

Re: 2 sets of bumpers legal?
 

The Q&A had been answered and some of the answers are somewhat surprising to me: http://forums.usfirst.org/showthread.php?t=12125

If your team is planning to match your bumper colors to the alliance/trailer color then you better read this Q&A.

As for our team all of the bumpers shipped in the crate so there won't be any withholding issues. We will have to mix up the bumpers like red on the front and back and blue on the sides or something and keep the others for spares/replacements.

Glad I brought this up though. I'm still not clear why it is a tactical advantage to match your bumper color to the alliance color. :confused: Seems like it is in full view of both alliances so it wouldn't favor just our team or alliance. The GDC has spoken, we have listened and will follow their ruling.

Re: 2 sets of bumpers legal?
 

I really wish all teams would follow this mind set. It would make things so much easier.

Re: 2 sets of bumpers legal?
 

Ah, but sometimes it is a valuable lesson when one chooses to "Challenge Authority".

(But, agreed, not in this specific instance)