Non-level bumpers

[EricH]

Originally Posted by Jared

See question 42 from the 2013 question and answer. It has the exact words from the blue box.

http://www.usfirst.org/sites/default...13_Q_and_A.pdf

If it was good to have angled bumpers with that answer, what rule makes it illegal this year?

As follows:

Q&A is not the rules. Correct? However, Q&A does interpret the rules, and give guidance on following them.

The difference between last year and this year is that this year, the ruling is in the rules, not the Q&A. Admittedly, it is in a blue box, AKA "intent and clarification", but it is still in the Manual.

Note too that the word "overtly" is used. Slight variations from level with the ground would probably be OK, you made the effort, but going from 10" (at the top) down to 7" (at the top) over the span of an 8" bumper would raise flags.

[GeeTwo]

I don't know how you're reading the "blue box". It specifically allows non-horizontal bumpers, as long as they stay in the 2"-10" range. Since the bumper is specified to be 5" high, that lets you slope it a massive 3". Even over an 8" run, I don't see that sloping it at atan(.375) =20 degrees is an "overt deviation", but then I'm not a judge. I think that they're trying to keep you from doing vertical pieces or something else silly, like putting a third row of pool noodle into that 3" of space.
That said, if you're design requires a bumper (or any other part) that you can't be sure fits the rules, change the design, or at least make a backup plan!

[magnets]

Originally Posted by GeeTwo

I don't know how you're reading the "blue box". It specifically allows non-horizontal bumpers, as long as they stay in the 2"-10" range. Since the bumper is specified to be 5" high, that lets you slope it a massive 3". Even over an 8" run, I don't see that sloping it at atan(.375) =20 degrees is an "overt deviation", but then I'm not a judge. I think that they're trying to keep you from doing vertical pieces or something else silly, like putting a third row of pool noodle into that 3" of space.
That said, if you're design requires a bumper (or any other part) that you can't be sure fits the rules, change the design, or at least make a backup plan!

The answer to q268 says that angled bumpers are not legal by referencing the blue box, which states they are legal, but don't forget, the blue boxes aren't really the rules like the rest of the manual...
EDIT: that's q199, not 268. oops.

[GeeTwo]

Originally Posted by magnets

The answer to q268 says that angled bumpers are not legal by referencing the blue box, which states they are legal, but don't forget, the blue boxes aren't really the rules like the rest of the manual...

And the answer posted on Q268 as I look at it now (several minutes after your post) says:

2014-01-31 by FRC5030
There is no published answer yet

Also, I read the question in 268 as probably referring to bumpers sloped so that the bottom of the bumper is not below the top of the bumper, since it is to " help aid the ball in rolling into our chassis". That is, sloped like snow plow or a cow catcher, not sloped so the bumper looks like a chevron when viewed from a distance.

[magnets]

sorry that's q199. It explicitly disallows angled bumpers. No doubt about it.

[FrankJ]

Fig 4-8 shows the bumpers being perpendicular to the floor. You really can't tell if they are parallel from the figure despite what the blue box says. I have always interpreted that rule to mean you cannot have "cow catcher" bumpers. We have never had a reason to mount one end of bumper lower than the other or have anything other than rectangular bumper so we never tested the exact meaning.

Currently you can have several bumper segments on on a side each one slightly higher. having the net effect of an angled bumper. Now as dX approaches 0....

[magnets]

Well, I thought I'd bring this back. Our team would really like angled bumpers (not like a cow catcher, but like 1114/67 in 2013), and we've been having quite an argument about the interpretation of the rule, and we were wondering what you guys thought.

There are currently three interpretations.

1.) The question and answer interprets the the blue box as saying no, so this year, the sentence in the blue box means the opposite as what it did last year, and angled bumpers are no good.

2.) The question and answer says that the blue box says no, and that sentence (which is a little ambiguous), means no, and 1114, 67, and 236 were all really illegal in 2013, but since the GDC never gave a clear response that year, no inspector could call them on it. (this is what I think)

3.) The q and a and game manual are in contradiction of each other.

Now, we may try some bumpers where the distance of each parallel segment is about 0.5" to get the same effect as angled bumpers.

If the GDC had put a rule in the original manual "bumpers must be parallel", then we wouldn't have had our sponsor waterjet an intake plate that only works with an angled bumper, or build a frame with an angled bumper, or build angled bumpers, or waste hours correcting the mistake. [/rant on bumper rules]

[EricH]

Originally Posted by GeeTwo

I don't know how you're reading the "blue box". It specifically allows non-horizontal bumpers, as long as they stay in the 2"-10" range.

There is no explicit requirement that BUMPERS be perfectly parallel to the floor, however the requirement that BUMPERS be constructed per Figure 4?8, the vertical cross-section, does implicitly mean that a BUMPER should not overtly deviate from this orientation.

Emphasis mine. The blue box specifically states that the bumpers are IMPLICITLY required to be as close as possible to horizontal. Not explicitly required to be one way is not the same as specifically allowed to be another way. You're not explicitly required to use any particular fabric on your bumper, but a particular fabric is specifically allowed by implication.

[magnets]

Originally Posted by EricH

There is no explicit requirement that BUMPERS be perfectly parallel to the floor, however the requirement that BUMPERS be constructed per Figure 4?8, the vertical cross-section, does implicitly mean that a BUMPER should not overtly deviate from this orientation.

Emphasis mine. The blue box specifically states that the bumpers are IMPLICITLY required to be as close as possible to horizontal. Not explicitly required to be one way is not the same as specifically allowed to be another way. You're not explicitly required to use any particular fabric on your bumper, but a particular fabric is specifically allowed by implication.

Then, the bumpers of 1114, 67, and 236 were illegal in 2013.

What I'm trying to get at is, if you're committing to a design off an assumption of a sentence in a manual based off a past Q&A answer, you should probably ask it on Q&A for some form of further clarification

I assumed that the interpretation given by the robot inspectors at the CT regional, GTR east, GTR west, Waterloo, Galileo, and the michigan district was correct and that robots that competed in the final match of their division at CMP (in a configuration that they had throughout the whole season) were not illegal. If we say that this interpretation could have been wrong, then it opens a huge door to changes

[Al Skierkiewicz]

Magnets,
It is irrelevant at this point that the interpretation was different last year. It is this year's Q&A that has answered the question as it applies on Feb 5, 2014 to 2014 robots.

[Chris is me]

"No" is unambiguous, but if bumpers have to be parallel to the floor, why does the manual say bumpers don't have to be parallel to the floor? Why not just change the blue text to say "bumpers must be as close to parallel to the floor as reasonable"?

Obviously angled bumpers are illegal if they say they're illegal, but I don't understand how the GDC would expect teams to interpret identical wording differently in different years.

[FrankJ]

Q199 said the bumpers had to be parallel to the ground. It also said the different bumper segments could be at different heights.

Maybe that gives enough room to creatively build the robot to meet your needs without lawering the rules?

[Alan Anderson]

I don't believe the GDC changed their mind between last year and this year. Nothing I've read indicates that the 2013 bumper rules permit angled bumpers. I think the Lead Robot Inspectors who gave angled bumpers a pass last year were not interpreting the rules the way they were intended. Since it was in teams' favor to accept that interpretation, nobody went up the chain of authority to get an ultimate ruling, and the LRI's word was final.

The answer from the GDC this year is clear: bumpers should not be angled. It's basically the same answer they gave last year, with the addition of the explicit "no".

[BBray_T1296]

We all do need to remember that the 2013 rulebook is completely nullified and 100% irrelevant for the 2014 game. Any rulings made in 2013 do not "roll over" into the new season. Just because they can Copy/Paste year to year, it doesn't mean we get to.

And next year in 2015, any arguments that are based on "how it was in 2014/2013/1992" will have no traction.

IMHO, having angled bumpers (relative to the vertical plane) is quite ridiculous. I would compare it to people in 2012 trying to "balance" on the bridge by driving up the Lexan guards underneath.

[Al Skierkiewicz]

Alan,
This specific ruling was discussed during multiple LRI meetings and conference calls. The answer in 2013 was any and all bumpers located between 2" and 10" above the floor were legal. I personally inspected several at each event.