Non-level bumpers

[Short Stuff]

When our team builds our bumpers do the tops of all the bumpers have to be at the same (or at least very similar) heights? To be more specific: Do the front and back bumpers have to be at the same height as the side bumpers?

[EricH]

Originally Posted by Short Stuff

When our team builds our bumpers do the tops of all the bumpers have to be at the same (or at least very similar) heights?

Please see Q199 and R22's blue box.

Longer answer: If a bumper section happened to be lower than the rest of the bumper sections, but the bumper was still level and entirely within the bumper zone, I can't see anything that would rule it illegal. However, if the bumper was angled, it would be illegal per R22 (blue box), clarified by Q199.

[magnets]

The same blue box was present in 2013, yet angled bumpers were ok.

[EricH]

Originally Posted by magnets

The same blue box was present in 2013, yet angled bumpers were ok.

No blue box in the bumper section of the 2013 rules says anything about angle of bumpers. I checked the archived 2013 Manual just to be sure.

[Jared]

Originally Posted by EricH

No blue box in the bumper section of the 2013 rules says anything about angle of bumpers. I checked the archived 2013 Manual just to be sure.

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?

[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 EricH

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.

So, between 2013 and 2014, the definition of "overtly deviate" has changed.
This is horrible and extremely frustrating for me, as our team has designed our pickup off of an angled bumper. We figured that since this EXACT SENTENCE allowed angled bumpers in the past, it would again allow angled bumpers in the future.


Here's the rule which allowed them in 2013, and disallows them in 2014. If this can happen for this rule, who's to say that a all of a sudden roughtop tread is a traction material, and all roughtop wheels are illegal?

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

To begin with, this is just the GDC being lazy and copying a sentence from next year's manual and not giving an answer. This really doesn't answer the question at all.
The first part (there is no explicit requirement that BUMPERS be perfectly parallel to the floor) is fine. It means "nowhere does it say bumpers must be perfectly parallel to the floor".

The next part "however the
requirement that BUMPERS be constructed per Figure 4-4, the vertical cross-section, does implicitly
mean that a BUMPER should not overtly deviate from this orientation." A vertical cross section of an angled bumper would have the pool noodles be slightly oval shaped.

In 2013, an oval would not be considered "overtly deviated" from a circle, which makes sense, as a very slight oval could be mistaken, by everybody's favorite "reasonably astute observer" as a circle.

In 2014, an oval does "overtly deviate" from a circle.

If they're making changes like this, I'm begging for them to let us know before halfway through build season after we've wasted a lot of time and money building three sets of nice angled bumpers. But we'll be keeping our angled bumpers, because I'd be willing to bet that between now and the end of build, there's a chance that the definition of "overtly deviate" will change again.

In 2013, we made 4 competition bumpers (red/blue, angled/nonangled) and two practice bumpers (angled/nonangled) because of unclear rules

This year, we've made 3 angled ones, and again, because of THE SAME RULE, we're making 3 more. This sucks. Can the GDC get any more unclear?

[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.

[Steven Donow]

Originally Posted by magnets

So, between 2013 and 2014, the definition of "overtly deviate" has changed.
This is horrible and extremely frustrating for me, as our team has designed our pickup off of an angled bumper. We figured that since this EXACT SENTENCE allowed angled bumpers in the past, it would again allow angled bumpers in the future.


Here's the rule which allowed them in 2013, and disallows them in 2014. If this can happen for this rule, who's to say that a all of a sudden roughtop tread is a traction material, and all roughtop wheels are illegal?


To begin with, this is just the GDC being lazy and copying a sentence from next year's manual and not giving an answer. This really doesn't answer the question at all.
The first part (there is no explicit requirement that BUMPERS be perfectly parallel to the floor) is fine. It means "nowhere does it say bumpers must be perfectly parallel to the floor".

The next part "however the
requirement that BUMPERS be constructed per Figure 4-4, the vertical cross-section, does implicitly
mean that a BUMPER should not overtly deviate from this orientation." A vertical cross section of an angled bumper would have the pool noodles be slightly oval shaped.

In 2013, an oval would not be considered "overtly deviated" from a circle, which makes sense, as a very slight oval could be mistaken, by everybody's favorite "reasonably astute observer" as a circle.

In 2014, an oval does "overtly deviate" from a circle.

If they're making changes like this, I'm begging for them to let us know before halfway through build season after we've wasted a lot of time and money building three sets of nice angled bumpers. But we'll be keeping our angled bumpers, because I'd be willing to bet that between now and the end of build, there's a chance that the definition of "overtly deviate" will change again.

If you're complaining about a Q&A answer (to a somewhat vague question to begin with) not being sufficient enough, then ask a Q&A yourself with a more specific question (ie. can a single bumper segment be at a 45 degree angle with the ground or something).

And if the rule you quoted allowed angled bumpers last year, maybe, it technically didn't, but there was no one who asked a Q&A to get an interpretation of that rule. Maybe the GDC's intent of not allowing traction devices DOES include roughtop tread. If someone asked the Q&A if roughtop tread is a traction device, then we'd know for sure their stance on that.

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

[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.

[Jared]

Originally Posted by EricH

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.

I think it's still a gray area. In 2013, since there was nothing in the rules about angled bumpers, we showed our inspector at CMP the Q and A answer. He brought it to the LRI, who said that the rules permitted our bumpers (and the bumpers of 1114 and 67). This means that the current blue box (without any interpretation) permits bumpers, which the q and a contradicts. Normally, the rules from the manual would trump the q and a response, but the sentence in question is a blue box. So, which get used, the blue box, or a q and a (which references the blue box in question)?

Or, if magnets is right, and the meaning of the sentence has changed because they are now providing an interpretation of this sentence instead of just giving us a vague sentence, this means that the correct interpretation for this year (not legal) contradicts what they wanted teams to get out of it last year (angled bumpers are legal), which again, doesn't make too much sense.

I think they should address this in a team update.

[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

[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.