BUMPERS ARGHHH!!!!
 

Well I have been reading through CD post on bumpers and in the offical Q&A. and my question hasnt been answered.

Were planning to use brackets or angles to connect two bumper backings (as not to violate rule RO8) to make one single bumper that covers the corner. And yes both segments are at least 6". Legal?? yes no??? nes?

Re: BUMPERS ARGHHH!!!!
 

Yes, that's legal so long as you comply with <R08> L (BUMPERS must be fixed to the BUMPER PERIMETER), with <R08> M (The entire length of the BUMPER backing must be supported by the structure/frame), and with <R08> N ("Hard" parts of the BUMPER ... may extend up to ... one inch beyond the BUMPER PERIMETER).

Re: BUMPERS ARGHHH!!!!
 

if i am understanding what you are saying, it sounds like you are going to connect the two plywood backings at the corner, so long as they do not extend beyond the metal that they are connected to and so long as they are 6" or more you should be ok

Re: BUMPERS ARGHHH!!!!
 

If the joint doesn't "extend into the corner", you won't be violating this rule.

Re: BUMPERS ARGHHH!!!!
 

Note the second sentence - it sounds like that is what you are trying to do. Don't do it.

Re: BUMPERS ARGHHH!!!!
 

I am so confused on these bumpers. The rules seem much more nebulus than in years prior. Is there an upper limit as to how high the bumper can be placed? Bottom limit? In the past they could be between the 2 and 8 inch mark from the ground. Someone mentioned they thought it was the 7inch limit for top. Can anyone confirm?

Also, I am not understanding Figure 8-4. I do not understand the okay versus not okay drawing. If the backing is within the 38" limit what is the problem?

I have read and read and read all the chief Delphi posts and the Q&A posts and am really confused. Is there one thread that really explains all this. I have been working on bumpers all the years we have had them and this is the first year of confusion.:confused:

Thanks for your patience.:)


Carolyn

Re: BUMPERS ARGHHH!!!!
 

Rule R08-P + check the definition of BUMPER ZONE.

Figure 8-4 is "Not OK" since the bumper backing is extending into the corner (a violation of rule R08-O).

Russ

Re: BUMPERS ARGHHH!!!!
 

The Game Manual confirms that the BUMPER ZONE is the region between one and seven inches above the floor. <R08>P confirms that the BUMPERS must be designed to remain within the BUMPER ZONE.

Re: BUMPERS ARGHHH!!!!
 

It sounds like you are thinking about doing something like this

http://www.chiefdelphi.com/forums/at...2&d=1233599363

If that is the case, I got this response from the Q&A about it

My interpretation of this is NO, you may not use a brace if you intend to permanently attach it to the bumper assembly. I came up with a solution to make a brace using "soft" parts of the bumper only. I can model it and post a picture here if you would like.

Re: BUMPERS ARGHHH!!!!
 

No that I know of. You're on your own. Good luck.

Re: BUMPERS ARGHHH!!!!
 

We are okay for Update #2 Section 8. We meet all these "rules" but what are the pictures on the top of the next page attempting to show? If our opening is less than 26" are we fine?

Re: BUMPERS ARGHHH!!!!
 

The pictures are not meant to be rules. If your opening is less than 26", you will almost certainly be fine as long as the bumpers cover the remaining foot with 6" on each side. (On a "wide" robot, it's 26"; a "narrow" robot has 16"due to the rules/the interpretation of protected.)

However, the pictures are not intended to show anything other than examples of legality with regards to one specific part of the rule.

Re: BUMPERS ARGHHH!!!!
 

Carolyn (et al) -

If there is still serious confusion about interpretations of the bumper rules, and how to apply the rules to your robot, please post specific, detailed questions to the FIRST Q& forums.

Chief Delphi forums are wonderful resources full of great technical information, team organization ideas, event details, strategy discussions, and related/unrelated topics too numerous to recount. But one thing that you can not find here is a binding determination of what a rule means or how it will be interpreted by the inspectors or referees at a competition. For those questions, you need to resort to the official FIRST Q&A forums.

The different answers you have received in this thread offer an excellent example of why you should refer to the official Q&A system for these sorts of questions. Some of the answers here, as well-intentioned as they may be (particularly by a few self-appointed rules experts that seem to post in every single thread), are just plain wrong. The inspectors follow the official guidelines delivered from FIRST, which are based solely on The Manual, the Team Updates, and the FIRST Q&A forums. Any rules interpretations you may get here will not carry any weight with the robot inspectors once you get to a competition.

When posting to the FIRST Q&A, try to make your question as specific and detailed as possible. The Q&A can't be used for a design review, but can be used to ask for clarification and understanding of what a rule means and how it will be applied. For example, it would not be appropriate to submit drawings of your robot and ask "is our robot legal?" But asking "does Rule <R09-P> mean that the entirety of the bumpers must be contained within the Bumper Zone, and therefore be between one and seven inches above the floor?" would be a great question that would result in an equally specific answer.

-dave


.

Re: BUMPERS ARGHHH!!!!
 

Thanks Dave. Would you think the Conference call on 2/5 would be good for official answers concerning bumpers too. My understanding is that they are going to go over how bumpers are going to be inspected.

Re: BUMPERS ARGHHH!!!!
 

In regard to the original question, you might find this Q&A forum answer helpful, in which basically the same question is addressed.

-dave



.

Re: BUMPERS ARGHHH!!!!
 

http://www.chiefdelphi.com/forums/sh...60&postcount=1

Another potential resource.

Re: BUMPERS ARGHHH!!!!
 

what are y'all using to fasten the bumpers to the robot??

Re: BUMPERS ARGHHH!!!!
 

http://www.chiefdelphi.com/forums/at...2&d=1233599363

Would attaching a brace to the outside of the bumper backing make any difference?

Re: BUMPERS ARGHHH!!!!
 

if your talking about conectingg two boards to gether then putting the noodles horizontal acrost the board and one vertical at the corner thenn wrapping it all in fabric it is fine but your boards have to run the lingth of the robot so if it gets hit it will not break off your brakets but i sugest you do it all sepprate so it is easier to get in to your electrical from the side if you need to but i dont know what your bot looks like so i cant realy tell you how to build them but your idea will work just fine.:) i hope thats the answer your looking for:P

Re: BUMPERS ARGHHH!!!!
 

Bigflip, the proposed brace location would not be legal. If it's outside the backing, it's either a) dangerously close to the 1" limit in <R08-N> and violating <R08-O>, or it's out by <R08-O> due to this Q&A.

powerkane, check <R08-O>. You can't put the backing into the corner areas.

Re: BUMPERS ARGHHH!!!!
 

My meaningless vote is with BigFlip. I have a pending Q about it, something like this: is there a limit to how far inside the robot perimeter the bumper part of a bumper bracket may extend? Is there a limit to the number of bumper segments that may attach to one bracket?
Until overruled by tonight's conf call, or the Q&A, I intend to have two solid horizontal left side plywood braces whose edges are coincident with the robot perimeter but extend inward above/below the frame, and permanently attach the bumper segments to it. This will stiffen the frame as well. Attached with bottom bolts through the bottom/frame/tee-nuts in top brace.

Bumper weight: my prototype 48" x 5" x 3/4" oak plywood weighs about 3 lbs. With two full length noodles and fabric, about 4.5 lbs. This represents the weight of all left side bumper segments, so I have 4.5 lbs of margin to add braces, staples/glue to hold fabric, bolts, t-nuts, screws, etc, per side,
to add up to 18lbs.
I imagine I'll have to leave an inspection flap at the corners to show the inspector that the bumper segments meet point to point at the corner without intruding into the corner. Since this is stock frame, I'll have to have pockets drilled in the bumper backing for the axle bolts, which makes the robot perimeter a little fuzzy.

18lbs of bumpers seems like a lot compared to some fancy milled aluminum 3 lbs frames I read about here...

The top edge of the bumper needs much more bracing than the bottom,
given the bumper zone is not centered on the stock frame.

Re: BUMPERS ARGHHH!!!!
 

i is pwned i need to read the rules sorry i was just sayin that it is a good design tho

Re: BUMPERS ARGHHH!!!!
 

Bumper weight....I seem to recall some teams in past years having trouble making the bumpers meet the maximum weight limit, because they built them as shown in the drawing in the rules, with aluminum angle on the the back corners to hold the fabric to the wood. Perhaps that's why the weight limit was increased from 15 lbs to 18 lbs?

Re: BUMPERS ARGHHH!!!!
 

http://forums.usfirst.org/showthread.php?t=11771

Please note, however, that this is specifically for the bumper part of a multi-part attachment system. I would assume that it goes for non-multi-part systems as well, but use caution.

I'm wrong in my previous post, I think. The way I now interpret this is: it depends on what you define as "outside". If it's relative to the center of the robot, my interpretation stands. If it's inside the backing from that point of reference, then it's legal.

The correct interpretation seems to be: if it's inside the perimeter, you're good, otherwise, you're not.