Non-sagging Bumpers Q&A Response
 

In previous years I have been on teams and seen teams that have secured their pool noodles to their bumper wood before wrapping them in the outside cover.

I have always thought that it was fine even though it was never mentioned in the rules. It makes construction much easier and it makes the bumpers look nicer.

However when I posted in the Q&A about it this year, the GDC came back with a simple answer, No it's not legal.

This practice has been pretty common on a lot of teams to avoid having sagging bumpers. Will this change how your team makes their bumpers?

Re: Non-sagging Bumpers Q&A Response
 

The GDC is correct - Tape (most often of the duct variety), shrink wrap, etc are not part of the official cross-section for bumpers - wood, pool noodles, cloth covering, optional angle on the top and bottom, and mounting hardware. I wonder how the GDC would respond to the same question regarding gaffers tape, though? Gaffers tape is classified as cloth, and I know I've borrowed a little from the field in the past to help teams do quick bumper repairs when needed (since the field usually has some red and blue available).

But now that that question is out of the way, I'd like to see the GDC address sagging bumper covers and get consistent ruling on those on the field. It's one of my personal pet peeves when it comes to robots.

Re: Non-sagging Bumpers Q&A Response
 

Makes me glad we planned to have smaller bumper sections this year. Guess its time to shift them up in the bumper zone to account for sag.

Re: Non-sagging Bumpers Q&A Response
 

I've already asked the follow up question about Gaffers Tape. If they say no to that too then I'll be very confused. What about strips of fabric that are stapled on to the wood and around the noodles before the cover is placed on.

There should be some way to do this without requiring 6 students to try to tug on the fabric while a seventh staples it.

Re: Non-sagging Bumpers Q&A Response
 

We've used two strips of tape for several years, and I'm pretty sure that's how our bumpers have already been made. ::rtm::

Hmmm...

I've never made a bumper without tape. Might have to disassemble ours tonight...

Re: Non-sagging Bumpers Q&A Response
 

Goes to show: don't ask the question if you're unprepared for a disappointing answer.

Re: Non-sagging Bumpers Q&A Response
 

The rigidity of the GDC really bothers me sometimes...

Re: Non-sagging Bumpers Q&A Response
 

I don't know if I've ever seen bumpers made without tape underneath...


Hopefully this answer was just an oversight/quick misinterpretation by the GDC and will be overturned soon...it arguably is a "pointless restriction", ie. you really get no significant competitive advantage by taping down your pool noodles.

You can definitely get a competitive advantage if your bumpers are more rigid than others'.

You gain a higher ability to control movement while in pushing matches. If you were to fully laminate your pool noodles with tape or other binding (we've only ever used enough to hold the noodles up, per the spirit of FIRST), you would be able to interact with other bots on a whole new level. Similar, but reduced, results can be found when wrapping heavyweight cloth more tightly vs loose, light cloth.

Re: Non-sagging Bumpers Q&A Response
 

We've taped out pool noodles to the wood for years now, and sagging has never been an issue. There's no need to over-engineer bumpers :P

Re: Non-sagging Bumpers Q&A Response
 

Yes, except the GDC has just ruled via Q&A that taping the bumpers to the wood is illegal.

Re: Non-sagging Bumpers Q&A Response
 

You could also clamp the fabric with some angle or flatbar across the top to aid in keeping it tight.

-Nick

Re: Non-sagging Bumpers Q&A Response
 

One thing that 971 has been doing for the past few years to keep the fabric tight is using a custom clamp-compression tool:

https://picasaweb.google.com/1177698...07224523241618

https://picasaweb.google.com/1177698...07277222737666

The bumper fabric is stapled while the noodles are compressed, and everything tightens up when the noodles are allowed to expand again.

Re: Non-sagging Bumpers Q&A Response
 

We used a loop of fabric this year and it works amazingly better than tape or zip ties ever did in the past. We used two four inch stops on the short side of our robot and three on the long side.

Re: Non-sagging Bumpers Q&A Response
 

One method that I remember doing on 1519 one year was use string to hold the pool noodles to the plywood. After you staple on the fabric, pull out the string and voila! You get the non-sagging bumpers and you leave nothing past the plywood that is illegal.

Re: Non-sagging Bumpers Q&A Response
 

I am completely shocked... Our team has been using tape ever since bumpers bumpers became mandatory without ever thinkig about it. Also, 2 years ago, we had to tape apart our bumpers because they were 1/4 inch short (another unfortunate, long story) and the inspector watched us cut the tape off as we remade the bumpers. I'm just surprised that he didn't call us out on the tape after the barely too short bumpers.

Re: Non-sagging Bumpers Q&A Response
 

What are they going to do to enforce this? Come cut open my bumpers? That'll be the day I quit.

We need a "Don't ask" culture for stuff like this an Q/A, just like when SlickDeals has this "Don't Call" culture for their hot deals forum postings. It seems like something that nobody ever thought twice about before is suddenly ruled illegal as soon as someone asks.

Re: Non-sagging Bumpers Q&A Response
 

As far as I know, no inspector has ever known this to be illegal or at least I have never spoken with any of them about it.

There are plenty of rules that are unenforceable. It's enforced by the last line on the inspection sheet that requires a mentor and student to attest to compliance with all rules, including this one.

Re: Non-sagging Bumpers Q&A Response
 

Would wood glue fall under the soft material of the question to the GDC? It isn't in the same category as tape or shrink wrap.

Re: Non-sagging Bumpers Q&A Response
 

Our team has always used a spray on adhesive to hold the pool noodles onto the wood so that we could pull our fabric tight. Haven't had an issue with them sagging.

Re: Non-sagging Bumpers Q&A Response
 

I agree this is practically unenforceable, but I suspect FIRSTers will step up and make their grandmothers proud.

Re: Non-sagging Bumpers Q&A Response
 

Guys,
WildStang has never used an adhesive or tape to secure the pool noodles prior to stapling the fabric. We fold over one edge and then staple it to the plywood. Then add the noodles, and pull the fabric tight around the plywood. We fold over the other edge and while pulling tight, we staple the second edge. It takes a little extra effort and usually two students working together, but it works as intended.

Re: Non-sagging Bumpers Q&A Response
 

An interesting situation for those of us living in the dry desert. We stretch our cloth very tight for great looking bumpers then go to a regional or Champs where humid conditions produce saggy bumpers. Shall we now presoak them before fabrication and stretch tight, hoping we didn't over stretch. Seriously, what logical reason is there for disallowing 2 strips of tape on a bumper???

Re: Non-sagging Bumpers Q&A Response
 

I fail to see how this is a big deal. Neat looking bumpers can be accomplished without tape, as people have pointed out in this thread. Not to mention we're allowed to work on bumpers passed the bag date and even re-use them from year to year.

This is a non-issue.

Re: Non-sagging Bumpers Q&A Response
 

The issue I see is not that a bumper can be made without tape, it is that it pointlessly disallows something that teams have been using.

Re: Non-sagging Bumpers Q&A Response
 

The rationale that they're not listed among the components permitted in bumpers is relatively persuasive, and I'm pretty sure this was specifically ruled illegal in at least a few past years. I suspect it may have been ruled legal at one point as well, but I'm not certain (nor am I going to search for it tonight).

As an inspector I've certainly explained to teams that the zip-ties, strips of tape or beads of adhesive underneath the fabric were not legal given the applicable rules and Q&A guidance. And like Al, I've had little trouble making adequately tight bumpers without resorting to internal fasteners of any kind.

I still think the bumper rules should be fundamentally based on simple tests of performance (with fidelity to a standard design meriting an automatic pass). By that rationale, if the taped bumper was clearly equivalent, there would be no problem. But since FIRST hasn't chosen this route, and given the simplicity of the solution (use removable string or an extra pair of hands while stapling), I don't have much sympathy for teams that are deliberately in violation. Inadvertent violators should probably read the rules more closely, but this would be low on the (long, but shorter than it used to be) list of bumper violations to enforce at inspection.

Re: Non-sagging Bumpers Q&A Response
 

Teams (collectively or individually) have vested interests in particular interpretations or particular ambiguities. The realization that a lack of an answer can sometimes be valuable means that some difficult questions don't get asked, for fear of a capricious or otherwise unfavourable answer.

The inability of disinterested parties (mainly the officials who have to enforce these rules) to get public clarifications is pretty big flaw in the Q&A, and has been since the days it transitioned from an e-mail system to a posting-based system (around 2002).

Re: Non-sagging Bumpers Q&A Response
 

I am about to really throw a wrench into things. If tape is not legal because it is not listed as an allowable material, then staples are also not legal. A careful reading of the bumper rules shows that if we take a strict interpretation of only allowing items listed in the rules, then we are limited to 3/4" plywood, pool noodles, sturdy cloth, aluminum angle, wood screws, and some unspecified attachment system.

So, who is going to ask Q&A about staples? Any takers?

Re: Non-sagging Bumpers Q&A Response
 

Martin,
I am going to go out on a limb and state that fasteners are expected for attaching the cloth to the backing material. Be they staples, tacks, etc. (or barbed wire fencing nails) as long as the other rules are followed, they will be acceptable. The aluminum angle is "optional" so it cannot be the only attachment that the GDC expects to see.
As to changes in humidity, I can only see that bumpers from a desert would swell with humidity making them more tight. The plywood, and to a very small extent, the Cordura fabric and the noodles, are all going to absorb some moisture. (Assuming you are not buying the Cordura Stretch Fabric)
All of this being said, everyone that knows me knows that sagging, ugly bumpers do not impress me. I am a TV engineer and it just doesn't look good for TV.
Dave, Inspectors will only ask to disassemble bumpers if they think there are illegal hard parts used int eh construction. And yes, we have seen steel and brass round bar stock and threaded rod inside the noodles, steel plate behind the noodles, and lead melted into holes in the plywood. If you can think of it, we have seen it.

Re: Non-sagging Bumpers Q&A Response
 

My point is that they disallowed tape for bumpers, so there must be a basis for doing so. The only basis I can see is that tape is not specifically allowed (since tape is an allowed fabrication material this year). By that interpretation, then staples are not allowed either. The rules DO allow wood screws, either with or without the optional angle. You can't argue one without the other.

I deal with government requirements all he time. They are usually poorly written and have a similar Q&A system, and answers are often similar to the short capricious answers given by the GDC. Each answer has huge implications to other rules based on the basis for that answer.

Re: Non-sagging Bumpers Q&A Response
 

Where do you see tape as a fabrication material?

Re: Non-sagging Bumpers Q&A Response
 

I stand corrected. Tape used to be specifically disallowed, but has been legal since 2009. I remember a caveat that they would re-evaluate its use and if tape became an issue they would make it illegal again. They have not yet done so, but it is not specifically allowed. Then again, as I said, neither is aluminum, fiberglass, carbon fiber, wood, polycarbonate, PVC etc.

Re: Non-sagging Bumpers Q&A Response
 

OK, thought I was losing it...
As a side story, we all thought for years that Duct Tape was a disallowed material only because Dean and Woodie once discussed they thought it was ugly. (and rightly so) However as once pointed out to me by a GDC member, Duct Tape was never on a disallowed list. However, even today it is not considered a fastener and should not be used as such.

Re: Non-sagging Bumpers Q&A Response
 

(emphasis mine)

From the 2008 robot rules:

And then in 2009, that rule disappeared.

From the 2009 Q&A:

Re: Non-sagging Bumpers Q&A Response
 

You have GOT to be kidding...that just kind of steams me. As for the duct tape issue, we have always used one strip on each end to secure noodles. At this point I am glad we haven't wrapped ours in fabric yet so we can remove the tape.

The bottom line as far as I am concerned is that the GDC got a question and answered the question. Period. What they say goes no matter what or how I think about the rule.

Look at this in terms of producing an engineering product for a customer. If they say a particular part cannot be used it's their call they are paying for your services. You choose whether or not you can fulfill the order under those specifications.

Same thing here. While 'payment' is a non-factor we are electively participating in a 'real world engineering project' and if a part is disallowed it is disallowed. Just glad Gregory posted it here so everyone would know.

Re: Non-sagging Bumpers Q&A Response
 

This is exactly the way I look at the rules, as a set of customer specifications. I deal with specification and requirements every day. The problems (both in work life and FIRST) comes in the interpretation of those specifications and requirements.

When the GDC answers a question, it is often interpreting the rules. When you receive a rule interpretation on a specific question, that interpretation applies that rule across the board, not just to that question. That is why companies are very careful when asking questions about specifications and requirements. If the question is not carefully worded, the answer can have broad reaching implications, far beyond what the questioner intended.

Re: Non-sagging Bumpers Q&A Response
 

I should have added that a team long ago used tape to change (compress) the profile of the pool noodles. This is likely the history behind the answer. Not a valid explanation I know but just some history.

Re: Non-sagging Bumpers Q&A Response
 

This is real-world stuff.

I saw a promising engineer's career get derailed when he did not "lawyer" the customer's specification for the project he was leading. The project went way over-budget as a result.

Re: Non-sagging Bumpers Q&A Response
 

Point taken and agreed to.

And in most companies there is someone to head off those types of questions (right or wrong is for someone else to decide) but in FIRST the ultimate decider of what get's posted in Q&A is (or should be) the lead coach/mentor. If this was a legit question for their team then it was appropriate to ask and if it was intended by the GDC all along then we all needed to be honoring it anyway.

Re: Non-sagging Bumpers Q&A Response
 

I absolutely agree. All we need to know in order to do that is; what was intended by the GDC?

Re: Non-sagging Bumpers Q&A Response
 

I guess asking them to clarify would be pushing the envelope? ::rtm::

Re: Non-sagging Bumpers Q&A Response
 

I believe it is a necessary follow up. Obviously needs to be very carefully worded, however.

Would I be stirring the pot more to point out that duct tape is technically "cloth,"* certainly smooth, and demonstrably rugged.

* From Webster's Dictionary"
Cloth - a pliable material made usually by weaving, felting, or knitting natural or synthetic fibers and filaments

Re: Non-sagging Bumpers Q&A Response
 

Suggestions for appropriate wording would be highly appreciated :D

Perhaps,

'In seeking clarification on [insert previously stated question here] is it permissible to:
1. Secure the noodles to the bumpers so that when the fabric is removed the noodles remain attached to the backing
and
2. Use staples to attach the fabric to the bumper backing'

Thoughts?

Re: Non-sagging Bumpers Q&A Response
 

Perhaps adding:

3. Please give a rules basis for your answer

And hope that it is not taken as "bad attitude", or any other negative connotation.

Re: Non-sagging Bumpers Q&A Response
 

You're correct. I could have sworn that they'd addressed that in a past year, so I compared the current diagram to Figure 8-1 in <R37> from 2007. The old diagram made reference to staples and glue as possible options, and the Q&A of that year stated that either was acceptable in lieu of angle.

At some more recent date, they omitted that reference to staples/glue from the diagram (apparently in 2009, when clamping angle was no longer "optional" according to the rules), while maintaining the requirement that bumpers be constructed per the diagram. Aluminum angle was specified as optional in later years, but legal alternatives are no longer specified. It's worth a Q&A, and will presumably be the uncontroversial subject of an update to R21E.

Re: Non-sagging Bumpers Q&A Response
 

Martin,
The Q&A people do watch CD. Your point has been made and no, it is not taken as bad attitude.

Re: Non-sagging Bumpers Q&A Response
 

Al, correct me if I'm wrong but you seem to be saying that compressing the pool noodles is a bad thing. What rule does that violate? Other than the newly understood attachment ban. Pre-compressing noodles, like 971 does, seems completely within the rule set to me, assuming the team uses nothing but fabric, pool noodles, and wood.

Re: Non-sagging Bumpers Q&A Response
 

Allen,
The team used the tape to make the 2.5" noodle about 3/4".

Re: Non-sagging Bumpers Q&A Response
 

If a team did that with only fabric, would it be illegal? I don't think it would.

Re: Non-sagging Bumpers Q&A Response
 

If the pool noodles are compressed such that they appear to be (significantly) less than 2.5" in diameter (per R21C), then you could have problems with your inspector. In other words, when all is said and done, if I hold a tape measure up to your bumpers, I should be able to say "Yup, that looks like you used approximately 2 ½ in. round, petal, or hex pool noodles". If I do that test and I say "Hmm, it looks like your pool noodles are only 1.5" in diameter..." then you have a problem. At that point, you have to prove to me that you actually used 2.5" pool noodles, which means disassembling your bumpers, decompressing the noodles, and hoping they pop back out to somewhere close to 2.5". Then you get to sit there and explain to me why you compressed them and attempt to provide proof that compressing them doesn't compromise safety on the field or compromise the intended robot-robot or robot-field interaction that bumpers are designed to help protect. All in all, it will just make things much more painful for a team that attempts to compress their noodles.

Note that this isn't about a little pre-compression that you can do to get the fabric on then have the pool noodles expand to make everything firm - in that case I would expect the noodles would be "approximately 2 ½ in" when all was said and done. This would come into play for a team that, for example, flattened their pool noodles permanently in order to make their pickup mechanism work better (if having smaller bumpers in either the horizontal or vertical dimensions were required to make that particular mechanism work). These would be the type of bumpers that an LRI would spot from across a room and think "those don't look right".

Re: Non-sagging Bumpers Q&A Response
 

This makes sense to me. The problem is that the Q&A ruling doesn't seem to link to this reasoning in a particularly clear fashion. It's very easy (and possible) to use tape but not compress the bumpers severely, just like it would be possible to use fabric to heavily compress the bumpers. If this is the intent, the better option (IMO) would be to revise R21-C to read that the cushion material must extend to a minimum of 2-1/4" (or whatever number you want) and a maximum of 2-1/2". Right now it only gives an upper limit.

Saying you can't use tape is a rather indirect and ineffective way to achieve the result of not having severely compressed bumpers. Now, the Q&A question asked about tape specifically, but I feel like a revised response would be in order if the actual intent is to prevent severe bumper pre-compression.

I think that they may also be trying to avoid a team finding a particularly hard tape and wrapping the entire bumper with them underneath the fabric to change the way the bumpers respond. I think a more clear response would be something like:

"Small amounts of soft, flexible tape may be used to secure pool noodles to the wood backing to aid in assembly. Tape markings should not be visible from the outside of the cloth on completed bumper assemblies. Pool noodles must remain close to the 2-1/2" nominal diameter".

This gives teams a way to build their bumpers better, within the intent of the rules, and limits the tape's ability to be used for any competitive advantage or create an unsafe condition. It also gives the inspectors grounds to disqualify bumpers if it appears they are not using it for something other than an assembly aid, without being overly strict. It still relies on the inspector's judgement, but it becomes easier to judge the intention of the team.

Re: Non-sagging Bumpers Q&A Response
 

That rule makes complete sense but that is not the current rule, it doesn't say anything about the state of the noodle upon mounting it to the wood. I don't see how an inspector could demand that any team open the bumpers, especially if they had a sample made or any other way to prove that they used 2.5" pool noodles. There should be a defined edge, since it already been shown in this thread that having tighter bumpers is an advantage.

Even a rule that said "pool noodles should not be heavily compressed" would be good enough validation for me to be able to enforce that at an event, but currently I don't think I can enforce that interpretation.

Re: Non-sagging Bumpers Q&A Response
 

Remember when everyone complained that the bumper rules were too complex, and that they should be simplified?

Re: Non-sagging Bumpers Q&A Response
 

We've always tacked the pool noodles onto the plywood with hot glue. That's not tape, shrink wrap or an other soft material, but I'm getting the impression that its generally in the same category since it is securing the pool noodles to the plywood under the fabric.

Is this really not ok? I really though that was how everyone did it! We've helped a gazillion teams through the years build bumpers! This might ruin my day! :ahh:

Re: Non-sagging Bumpers Q&A Response
 

A team at our regional used their bumper fabric (not tape) to squish their bumpers in about 0.5" to get their climber working well. They were not allowed to compete with bumper like this even though no rule was shown to the team as to why is was illegal.

As far as I can tell, the only thing an inspector can call you out on for squishing your noodles to 0.25" thick is that it might be unsafe. However, this is kind of subjective.

If the GDC gives us simple rules that make sense (ie, don't squish the bumpers), teams won't try to "lawyer" the rules. If they give us nonsense rules and responses (speed racer in 08, 118 in 2012, unclear on angled bumpers in 2013, bumper fastening in 2014...), then expect to see teams try to get around the rules.

Re: Non-sagging Bumpers Q&A Response
 

Just a note... My response about pool noodle compression wasn't intended to be part of the "Great Tape debate of 2014" :) I was just replying to AllenGregoryIV's question about what rule pool noodle compression violated.

Re: Non-sagging Bumpers Q&A Response
 

In the bumper diagram the angle is listed as optional.
Since the angle is optional, there is another unspecified legal method for attaching the fabric to the plywood. I am going with staples without further official guidance

Re: Non-sagging Bumpers Q&A Response
 

To avoid misinterpretation and rule bending I think that rule references and/or rule intent should be included in any answers given by the Q&A people.

Re: Non-sagging Bumpers Q&A Response
 

This is a whole lot of debate about nothing. Yes we all want nice looking bumpers and we all need legal bumpers. Make your grandma proud, build them to spec. Don't worry about what was in the 2007/2008/2009/200x rules, we are in 2014 now.

Thank you to everyone who provided their methods of making bumpers, I'm sure someone will appreciate it. Several small things (like using a string then pulling it out) are crafty, creative, and something I never would have thought of (and legal in every sense of the word.

Can we just let this be? We spend 6 weeks creating a 150 lb metal robot, take pride in this as well as your bumpers but don't worry too much about the use of tape. Try and remember that the robot is just the vehicle too, FIRST is about much more than robots (and bumpers).

Re: Non-sagging Bumpers Q&A Response
 

To be fair, many questions Q&A is asked can be answered by looking at the Manual, without ever asking Q&A. (Or, in one case I saw this year, a Team Update.) And, many questions do reference rules, or are posted under that rule, so the GDC may not see a need to reference a rule when they answer.

Rule intent is trickier. Do you really want to inform several thousand people that a particular rule exists just for the "game challenge" (or other reason, as seen in this thread), and otherwise may or may not make any sense?

Re: Non-sagging Bumpers Q&A Response
 

The "Q&A people" are members of the Game Design Committee, the same group that authors the official game manual. Thus, the Q&A is generally understood to (1) carry the same weight as the manual and (2) act as an extension of the manual. There's no need for them to reference a specific rule that was published on Kickoff Day-- the GDC has the freedom to create new rules at any time. As willing (paying!) participants in FRC, we understand and tolerate this.

...often very begrudgingly.

Re: Non-sagging Bumpers Q&A Response
 

The reason I ask a lot of the questions I ask are two fold.

One I do run a team that will push the edge on occasion. We did a lot last year to try to pull as much current out of the battery as we could to the point where FTA's were trying to find problems with our robot because they thought we might brown out. This year we were working on compressed bumpers and we wanted to do it with in the rules, therefore we needed clarification on the rules and frankly I'm still not sure.

Second I'm also an LRI this year, I need to be the expert on the rules at my event and the rules need to be enforced consistently across events. Explanations help me do that so I can expand out to to other cases that I haven't yet thought to ask about.

Re: Non-sagging Bumpers Q&A Response
 

Regardless of if it is legal, what is the reason you were looking to compress the bumpers (pool noodles)? The benefit is not obvious to me.

Re: Non-sagging Bumpers Q&A Response
 

It keeps them from sagging below the bottom of the bumper zone, which would cause a robot disable under G20. That's a pretty obvious benefit, no?

Re: Non-sagging Bumpers Q&A Response
 

2013, it helped for climbing. This year, it lets you get small in one dimension while keeping the same amount of space in the robot. This is useful if you want to get as close to something as possible.

Re: Non-sagging Bumpers Q&A Response
 

Welp, time to send in a Q&A about glue. If that isn't allowed, we have a lot of rebuilding of our bumpers to do...

Re: Non-sagging Bumpers Q&A Response
 

From Post #10

Teams have been trying to get their bumpers stiffer for years, the rules have never outlawed compression (as far I know), so why not do it? I don't believe there is a spirit of the rules case here since it's not mentioned at all. As soon as the GDC rules on it, any team I'm on would never consider it and I would enforce it across the board as an inspector, but the current rule set makes no reference to it either way.

Re: Non-sagging Bumpers Q&A Response
 

I'm going to feel awful for all the teams who use sharpies, vinyl and iron-on sheets as they will have to re-make their bumpers as those materials are not listed in the rule book as acceptable bumper materials... I guess we are down to sewing on our bumper numbers?

Re: Non-sagging Bumpers Q&A Response
 

R21D mandates a "rugged smooth cloth" covering. Stitching would not be "smooth" depending on the standard applied.

Also, the rules make no mention of thread as part of a bumper, so I guess you need to disassemble your cloth to get the threads to do the stitching.

Seriously, I think we are all being a bit reactionary to this. GDC only addressed the means of fastening the pool noodles to the wood. Lets not leap off the jump to conclusions mat just to find ways that the rules make bumpers impossible to make.

Re: Non-sagging Bumpers Q&A Response
 

It could be useful for teams that have mechanisms that extend out and over the bumpers to contact the ball closer to the floor. Since the 20" extension is measured from the frame perimeter, a smaller bumper would give you more space.

Re: Non-sagging Bumpers Q&A Response
 

#bringbackdatape

Re: Non-sagging Bumpers Q&A Response
 

Dude... seriously.

On most of the PC+CNC west coast teams, bumpers are by far the ugliest parts.

Re: Non-sagging Bumpers Q&A Response
 

Dear Mr. Cubington,

I swear it wasn't my fault! Those darn freshman don't follow instructions!

Sincerely,

Dude who told kids to make those awful bumpers.

Re: Non-sagging Bumpers Q&A Response
 

OK, So I didn't think a simple answer would prompt such a reaction but wow, winter is really taking it's toll this year. So normally I would talk about bumpers in my annual inspection thread but I can deviate a little and discuss them here. This will be a history lesson, there will be a quiz at the end.
A long time ago, many of us were disappointed in the destruction robots were encountering in vigorous match play. The GDC led by Woodie and Dave, as I remember, came up with the bumper concept. Dave once told me that they tried different configurations, materials, etc. until they came up with a simple system that could protect robots. Today's bumpers are a result of that long progression. They began as two stacked 2.5" round pool noodles to provide a resilient boundary, backed by 3/4" plywood, covered in Cordura and firmly attached to the robot frame. They noticed in their testing that the fabric sometimes pulled out of the staples in the bigger robot to object contact so they added the "optional" aluminum angle. Please note, it is the 2.5" of noodle that was found to work well at not only absorbing the hit but in also preventing damage to the opposing robot. That is 2.5" not 1" and not 3 cm. Anything less compressed with contact and anything more conducted too much force. During the intitial season, Woodie and the rest of us noticed that robot damage was eliminated for the most part and it was good. So on the record and for all to see, I like bumpers. So many of you asked questions, provided input and suggestions on how to make this better and we listened and adapted. The plywood has been modified to allow "robust wood" so teams can pull lumber out of their garage and make the bumper for no cost. The round pool noodles have been changed to "approximately 2 ½ in. round, petal, or hex “pool noodles” (solid or hollow)". This is due to teams (particularly in the northern latitudes and foreign countries) having trouble finding hollow, round noodles. The Cordura has been changed to "rugged, smooth cloth" to allow teams that can't find Cordura to use something almost the same. The smooth specification is to prevent a robot from "sticking" to another using a high friction fabric. The complete bumper system has been modified to 8" on both sides of the corner to allow teams a little more variable in the design of pickup devices. We saw teams struggling with mounting them to the frame with no gaps, so we allowed for bolt heads, weld beads, irregular frame parts up to 1/4" and gaps no more than 8" wide because a hard hit on the plywood with a larger gap caused it to fail. The reason the corners must be protected should be obvious, it is to protect other robots. Team numbers (I cannot lie) is a "WildStang rule" since we first put numbers on our bumpers many years ago and the GDC liked that. Sorry. The GDC came up with the color, which is a "free" way to identify alliances compared to a 2.5 lb, 4 amp, rotating light with interchangeable lens. And finally, the bumpers were part of the robot so they had to be rebuilt every year, both colors, prior to stop build, and shipped or bagged with the robot.
So where does that leave us? The 2014 Bumper Rules, all of them. So in my opinion, using anything but robust wood, 3/4" thick with 2.5" pool noodles (uncompressed by "tape or other soft material") covered in strong fabric like Cordura and firmly mounted to the robot frame works to protect not only your robot but everyone and everything you contact and doesn't give you an advantage that other teams don't have. Inspectors should be looking at your bumper system with these items in mind.
I inspect bumpers by holding them and looking at the construction and then check them when mounted. I look for obvious compression of the pool noodles by any material, signs of something other than pool noodles covered by fabric, 3/4" thick wood backing, two colors using any method, with team numbers that are readable from a distance. They should look like the cross sectional drawing in the rules. I want them to firmly attach to the robot so that they don't fail you. I should be able to punch any part of your bumper including the corners, and not hurt myself by contacting hard parts. And I want them to look nice, they are complementing your robot after all. That means not sagging, falling off, barely attached or fabric pulling out. Think of them as your robot's tie, it just puts a nice finish on your hard work.
So is there any real surprise there? No, these are all things you already knew and what you have known all along. This is what I believe all teams want their inspector to do. I will pass along your concerns about needing a third hand to hold the noodles in place while you wrap fabric. I don't think that is unreasonable as long as the noodles are not compressed.

Re: Non-sagging Bumpers Q&A Response
 

A "third hand", gently applied, would be much appreciated, Al!

Re: Non-sagging Bumpers Q&A Response
 

Thanks for the further input/history lesson, Al. You're awrdome at what you do and explaining what you do.


My question for you is, since obviously you can't expect(at least in my opinion) EXACTLY 2.5 in pool noodles, what's a reasonable, legal tolerance on that? Its hard, in my experience, to get a nice, taut covering of the bumpers without compressing the pool noodle somewhat. Maybe this question is missing the point of what you said, or maybe I'm just a little OCD about wrapping bumpers. Any input?

Re: Non-sagging Bumpers Q&A Response
 

The pool noodles are not exactly 2.5" But the small amount that you compress while making tight fabric is not significant. We learned how to make them tight from some of our team moms, my wife among them. Believe me, if you want them to look nice get some parents involved.

Re: Non-sagging Bumpers Q&A Response
 

As Inspectors, it's not our job to lawyer the rules, only to enforce them. When the rules are clear cut (like the 112" frame perimeter), we enforce it as strictly as the rules call for. When they aren't clear cut (like the approximately 2.5" pool noodles), we don't go looking for trouble. We aren't going to measure every noodle and set some arbitrary limit for "close enough" that isn't already in the rules. In fact, I personally avoid trying to measure something like that unless I have reason to suspect something is wrong - by look the bumpers are clearly not as big as all the other bumpers in the regional, or by feel the noodles don't feel like the hundreds of other noodles I've grabbed in the past few years, or be weight your bumpers are an outlier (when compared to other similar sized bumpers) with no readily apparent (like giant steel mounting brackets) explanation for it. If you make bumpers that look like like all the other bumpers we see on every robot (especially if they look nice!), we'll be focusing on other things.

Re: Non-sagging Bumpers Q&A Response
 

Al, thank you for the explanation. So your interruption is that the rule regarding using 2.5" Pool noodles, dictates the state that they are in when on the robot? That seems very odd to me. I am really trying to find a way to justify teams not compressing bumpers in the rules and that rule has always read to me that the pool noodles should be manufactured at 2.5". Otherwise a team could use larger pool noodles and compress them down to 2.5" diameter and that doesn't seem legal either. What I'm trying to get at is the rule set seems incomplete. If the GDC's intent is for bumper pool noodles not to be compressed their should be a rule that states that. Under the current rule set I would have a hard time justifying forcing a team with compressed bumpers to remake their bumpers.

Re: Non-sagging Bumpers Q&A Response
 

[quote=Al Skierkiewicz;1334700]OK, So I didn't think a simple answer would prompt such a reaction but wow, winter is really taking it's toll this year. So normally I would talk about bumpers in my annual inspection thread but I can deviate a little and discuss them here. This will be a history lesson, there will be a quiz at the end. [...edited down]

...wait. Where's my quiz? I like quizzes.
Is this like a "What kind of bumpers would you be?" quiz that Buzzfeed would post?

Re: Non-sagging Bumpers Q&A Response
 

If they compressed their pool noodles significantly, how can you know they used the proper diameter noodles without having them take apart their bumpers and show the noodles in an uncompressed state?

Re: Non-sagging Bumpers Q&A Response
 

Many ways, the main one being a group of 20+ people including students tell that they did, maybe I'm an optimist but I like to believe an entire FRC team isn't going to lie to my face. It's the same way I know a team didn't put some hazardous material inside any of their extrusion, they tell me they didn't. I don't require them to take apart their robot to prove it's not there.

If you want more evidence a team could have photos of them constructing them, or they could have a sample bumper section they are willing to take apart.

Re: Non-sagging Bumpers Q&A Response
 

Alright I know no one wants to see this thread brought back up but the GDC has cleared up some of the issues with another short and sweet response.

Q302
That's not the way I have read the rule over the past couple years, but it's entirely valid and the way it will be enforced.

A follow up question to the initial question about securing pool noodles using gaffers tape has still not been answered.

Re: Non-sagging Bumpers Q&A Response
 

Does Q302 now make it illegal to have anything but straight bumper segments, as any curve compresses the pool noodle. I guess Figure 4-5 will have to be modified.

Re: Non-sagging Bumpers Q&A Response
 

I'm not really sure, we used to wrap the pool noodles around the corners but they are definitely much smaller than 2.5" once that happens.

Re: Non-sagging Bumpers Q&A Response
 

Emphasis mine. Just to be clear, are you agreeing this is legal? Given that robust mounting is legally required, is there something against steel or largeness? We use steel to secure our brackets to the wood.

Re: Non-sagging Bumpers Q&A Response
 

In 2012, at the recommendation of a Lead Robot Inspector/Mentor on our team we used a steel plate-- about 28" x ~3" bent into a 'J' shape that ran the length of the bumper and engaged our frame member. It passed inspections at regionals. This included an inspector named Al, who you might be familiar with ;) The entire length of the steel was part of making a very robust attachment system.

But adding steel (or any other material) with no purpose other than adding weight or strengthening the bumper plywood would be a no no, I believe. The method we used had the primary purpose of attachment to frame, and it incidentally added weight and bumper rigidity.

Re: Non-sagging Bumpers Q&A Response
 

Okay, so you can't tape noodles, and you can't compress noodles at all? I guess all of our bumpers will be saggy this year. Don't pull that fabric too tight, or else you'll compress the bumper a little bit!

Seriously, the only thing that stops a pool noodle from sagging is fabric tension, which compresses the noodle (even a little bit is illegal according to that ruling). By the letter of the ruling, any non-saggy bumper should fail inspection for compression, and any saggy bumper should fail for, well, sagging. I honestly believe at this point that the GDC has never built a set of bumpers.

Re: Non-sagging Bumpers Q&A Response
 

not taping the noodles doesnt effect the bumper too badly, my team made one set of bumpers today, and we managed to get an non saggy bumper with little to no compression of the noddles. all it takes is a little finagling .

Re: Non-sagging Bumpers Q&A Response
 

Joe,
I believe the fig as highlighted is meant to show a mitered corner, not a wrapped corner.
Tightly wrapping the fabric may change the shape but is unlikely to really compress the noodle. I would challenge any inspector to be able to tell that a noodle is compressed by merely the fabric. We see a majority of bumpers that are made nice and tight with fabric alone every year. Like I said, ask a team mom or anyone who has done any upholstery for some help. You and your inspection team will like the result.

Re: Non-sagging Bumpers Q&A Response
 

Al,

Even as the chief robot inspector "I believe" doesn't cut it vs the official FIRST Q&A.

It is my hope that they clear this up with a "common sense" and "astute observation" clause because right now any fabric that will look good will be slightly compressing the pool noodles.

Re: Non-sagging Bumpers Q&A Response
 

The only way to ensure a noodle is not being compressed (at all) is to have it sitting in a loose sack of fabric. Not only will that look atrocious, it is potentially nullifying the safety effects of the bumpers to begin with.

Really hoping for some common sense and clarity to come out soon. This whole thing seems way overblown at this point and the further it plays out this way, the less time teams will have to react at the end of the build season.

-Brando

Re: Non-sagging Bumpers Q&A Response
 

Guys,
Virtually everyone here has great looking bumpers. Have I ever failed your bumper design? Are you compressing the noodle such that it doesn't meet the rule R21 when you make your fabric tight? No, of course not. You do realize that you don't have to work on your bumpers until next week right? They are not required to be in the bag and don't count towards the with holding either. I know (and my inspection team has the experience to know) when I look at a bumper that it has compressed noodles and doesn't fit the rule.

Keep working on your robots today and wait for a while on your bumper design.

Re: Non-sagging Bumpers Q&A Response
 

I think a lot of the frustration this year in that regard is that this year more than ever in the 'red/blue bumper'-era(2010-present), teams are designing (and, if you're having an intake, pretty much have to at least take into account) intakes that involve gamepiece-bumper interaction.

Re: Non-sagging Bumpers Q&A Response
 

However, having properly made bumpers for practice and robot testing in the final days are important and can not be overlooked.

The problem with inspection is that the inspectors can interpret the rules or Q&A differently. Al, you might pass most bumpers that you can "hit" with your hand and not hurt yourself. But there might be one inspector at a district or regional that interprets the Q & A responses differently and if any portion of the pool noodle is less than 2.5" call them illegal because of compression.

I hope that FIRST doesn't plan to wait till Week 1 events to give to official ruling of illegal robots (ex. 2012). This needs to be addressed sooner than later.

-Clinton-

Re: Non-sagging Bumpers Q&A Response
 

Al-

I know what you're getting at, and believe me we will not be putting our bumpers in the bag.

But many teams are relying on their bumpers to fine tune their pickup systems, and many teams are heading to a scrimmage/practice this weekend (ours included). We're building bumpers now for that event, and the hope is they would be the final bumpers we use in competition.

That being said, obviously if any developments force us to change that, we will comply.

And to answer the question, you've never failed our bumpers, and thats where I'm hoping the common sense of this will shine through (meaning we don't necessarily have to do anything different than we have in the past).


-Brando

Re: Non-sagging Bumpers Q&A Response
 

LRIs have gone through training, are reading the posts here and on the FRC LRI forum and all of them have my personal phone number and email. This is not the first year where bumper design affected game piece pickup. Nothing has changed from that competition to this one. And yes, I have had many questions on this subject as many teams are planning to pickup from the floor requiring contact with at least some part of the bumper system, my own team included. As in past years, the GDC expects that no team may have an advantage because of the shape/profile/thickness/height/cross section of their bumper system. We are not trying to throw you a curve. Please be patient.

Re: Non-sagging Bumpers Q&A Response
 

It appears common sense has prevailed: Team Update 2014-02-11

Thanks, GDC!

Re: Non-sagging Bumpers Q&A Response
 

Yay! This is the intent is was hoping for. We've used tape in our bumpers for several years now, but we would never use the tape to make the bumpers compressed.

Now we don't have to rip the bumpers apart!