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Gregor 24-03-2013 16:06

Re: Bumper Restrictions
 
Quote:

Originally Posted by Jaxom (Post 1251960)
Yes, but....when teams don't know some of the rules, they tend not to know others. So while looking at the robot & talking to the team I get the sense that they don't really understand the basics, I take extra time to make sure they haven't missed some of the other things. So, if you don't know how to properly build bumpers (which, despite all the grumbling, are NOT hard) then I wonder if you didn't read the pneumatic rules either. So I'd better take an even harder look at something that could quickly become a safety issue.

That makes sense. Teams who build bumpers with extra weights typically know that section of the rules more than a given team, not less. If the weights comply with every rule, they clearly know what they're doing. Does this justify going over their robot with a fine tooth comb?

GaryVoshol 24-03-2013 16:15

Re: Bumper Restrictions
 
Quote:

Originally Posted by Gregor (Post 1251968)
That makes sense. Teams who build bumpers with extra weights typically know that section of the rules more than a given team, not less. If the weights comply with every rule, they clearly know what they're doing. Does this justify going over their robot with a fine tooth comb?

If they have skirted just to the edge of one section of the rules - perhaps having to weasel-word their way to passing - then what else may they have creatively interpreted? While their creative bumper design is just barely legal, maybe the electrical or pneumatic system is not legal.

Jaxom 24-03-2013 16:51

Re: Bumper Restrictions
 
Quote:

Originally Posted by Gregor (Post 1251968)
That makes sense. Teams who build bumpers with extra weights typically know that section of the rules more than a given team, not less. If the weights comply with every rule, they clearly know what they're doing. Does this justify going over their robot with a fine tooth comb?

I don't agree that they "...clearly know what they're doing." In my opinion teams that add weight to bumpers just to add weight to the robot didn't read this from section 4.1:
Quote:

When reading these rules, please use technical common sense (engineering thinking) rather than “lawyering” the interpretation and splitting hairs over the precise wording in an attempt to find loopholes. Try to understand the reasoning behind a rule.
What other parts of the rules didn't they read?

If I saw weighted bumpers where there is extra material that clearly wasn't needed as part of the attachment system or doesn't fit R24, I'd be inclined to think that there could be other places that the team also stretched the rules too thin. So while they were fixing their bumpers, I'd be looking for other things. ;)

And btw...I've never inspected a team that added weight to their bumpers just to add weight. This leads me to believe that the majority of teams understand why bumpers are supposed to be there, and reinforces my opinion that adding weight is just trying to find a loophole.

Aren_Hill 24-03-2013 17:03

Re: Bumper Restrictions
 
We have just recently added some steel bumper attachments/supports to the rear of our bumpers to effectively shift the center of gravity some.
Why? because its legal and it's what need

They already capped people being too crazy with weight by making a weight limit...I'm following said limit and not stretching anything.

dtengineering 24-03-2013 17:29

Re: Bumper Restrictions
 
I'm going to be inspecting in Seattle and Calgary over the next two weeks, and have been following the bumper discussions with interest. While final decisions, of course, will rest with the lead inspector, the idea of intentionally building heavier mounts to add weight/shift CoG, is an interesting one.

When I think of the bumper mounts that we built for our robots, we would often use 1/8"x1" steel band iron bolted to the noodle side of the plywood. We'd drill and tap the band iron and run bolts through the plywood and into the band iron, essentially using the tapped band iron as a fixed nut.

Well, would be have been wrong to use 1/4" x 1 1/2" steel? Would we have been wrong to use longer pieces of steel? Would we have been wrong to use 1/2" bolts instead of 1/4" bolts? Would we have been wrong to use four mount bolts at each mount point instead of two? Would we have been wrong to have four mounting points on our bumper instead of three? We probably would have been wrong to use depleted Uranium instead of steel, and using Gold would have put us over the $400 per part... but we could have used Brass to increase the density of the mount.

So we could have easily increased the weight of our mounts by a factor of 8 and still clearly been within the rules, so long as the overall weight was less than 20 pounds.

At some point the mounts might become so large as to reduce the protective nature of the bumpers... for instance if they begin to infringe upon the cross section of the pool noodles... or so long as to effectively violate the diagram (4-4, I believe) showing the cross-section of the bumpers. I think it would be reasonable for an inspector to insist that at some point along the length of the bumper (perhaps even along the majority of the length) the cross-section of the bumpers should match the diagram.

But bumpers that meet the rules meet the rules... even if they intentionally have heavier mounts than are structurally needed.. are legal.

Jason

Jon Stratis 24-03-2013 17:33

Re: Bumper Restrictions
 
Quote:

Originally Posted by Racer26 (Post 1251966)
I really don't understand why the bumper rules are such an annual sticking point. Anybody with some fabric, pool noodles, plywood, and a staple gun can build legal bumpers in an hour or two.

They're a problem for so many teams every year because teams ignore/forget about them until the last minute. Everyone is so focused on getting the robot built, that they don't bother with bumpers until the last minute, and even at that point they stick their least-capable students on it while everyone else focuses on the "harder stuff".

If more teams thought about bumpers earlier, and spent the time to make them right, then they wouldn't be a problem for anyone. For my team, we had one of our best students sign up to do bumpers, and she started on them a week before Stop Build Day... after she finished designing and building our climbing arm. The bumpers are reversible, look great, and can be mounted quickly (in fact, they mount quicker than any other set of bumpers we've had). Treating the bumpers as equally important as any other part of the robot leads to them looking just as good as the rest of the robot!

apples000 24-03-2013 17:34

Re: Bumper Restrictions
 
This may be slightly off-topic, but we saw a team with bumpers that were in the bumper zone, but not parallel to the ground. After reading some of the Q/A, it seems like they have to match the vertical cross-section shown in the manual which seems to make them illegal. Does anybody know for sure if these bumpers are legal or not?

Nathan Streeter 24-03-2013 17:35

Re: Bumper Restrictions
 
Quote:

Originally Posted by Jaxom (Post 1251992)
If I saw weighted bumpers where there is extra material that clearly wasn't needed as part of the attachment system or doesn't fit R24, I'd be inclined to think that there could be other places that the team also stretched the rules too thin.

I do agree that when a team stretches or bends rules, the inspectors should look more closely at other things... if you're willing to twist the rules how you like in one instance, you're likely willing to do it again in other places!

However, I disagree that adding weight to bumpers bends rules or requires any careful reading of the bumper rules. I just re-read the bumper rules and really didn't find a thing that made me feel iffy about adding weight (especially in the form of beefier brackets or reinforcments) to bumpers.

Given my experience with bumpers for our robots, it seems to me that every team should be able to make strong, legal bumpers for their robot that weigh 15 pounds or less. Why then has FIRST raised the weight budget for bumpers up to 20 pounds? Seems to me that FIRST isn't trying to get every team to have the same weight bumpers by having a high budget. If team's want light bumpers, make them light (while strong and legal!)... if team's want heavy bumpers, make them heavy (while legal and hopefully strong enough!).

Jaxom 24-03-2013 18:33

Re: Bumper Restrictions
 
Quote:

Originally Posted by apples000 (Post 1252018)
This may be slightly off-topic, but we saw a team with bumpers that were in the bumper zone, but not parallel to the ground. After reading some of the Q/A, it seems like they have to match the vertical cross-section shown in the manual which seems to make them illegal. Does anybody know for sure if these bumpers are legal or not?

Yes, they're legal. So are bumpers that are on more than one level, as long as they're totally within the bumper zone. Search the Q&A; I believe both were asked & answered.

Kevin Sevcik 24-03-2013 20:47

Re: Bumper Restrictions
 
On the topic of inspectors giving more detailed and exacting inspections to robots that "stretch the rules" regarding bumpers:

Do you inspectors actually have differing levels of inspection for different robots that you like or don't like? Are you actually in the habit of giving some robots a cursory inspection while going over others with a fine tooth comb? If so, what exactly is your reasoning for this? I'm curious, because I can't think of any reason to do only a cursory inspection on an uninspected robot. Unless you've worked with a team, you can't possibly know how well that team knows the robot rules. I've run across some very veteran teams that have missed things on inspections. And I've run across some LRI's (myself included) that have skimmed the rules and missed a detail or two. I'm pretty sure it benefits everyone to treat all robots the same and give everyone a thorough inspection.

So again, why exactly are you giving some robots less than a thorough inspection?

Jaxom 24-03-2013 21:57

Re: Bumper Restrictions
 
Quote:

Originally Posted by Kevin Sevcik (Post 1252121)
On the topic of inspectors giving more detailed and exacting inspections to robots that "stretch the rules" regarding bumpers:

Do you inspectors actually have differing levels of inspection for different robots that you like or don't like? Are you actually in the habit of giving some robots a cursory inspection while going over others with a fine tooth comb? If so, what exactly is your reasoning for this? I'm curious, because I can't think of any reason to do only a cursory inspection on an uninspected robot. Unless you've worked with a team, you can't possibly know how well that team knows the robot rules. I've run across some very veteran teams that have missed things on inspections. And I've run across some LRI's (myself included) that have skimmed the rules and missed a detail or two. I'm pretty sure it benefits everyone to treat all robots the same and give everyone a thorough inspection.

So again, why exactly are you giving some robots less than a thorough inspection?

You're making some pretty big assumptions. Who said anything about "like" or "don't like"? That potentially implies that there's some favoritism based on the team; I sure hope that's not what you meant. And who said "cursory"?

"cursory" vs. "thorough" != "thorough" vs. "double-check"

I can't think of a good reason to ever do a cursory inspection on an uninspected robot either.

Jon Stratis 24-03-2013 22:40

Re: Bumper Restrictions
 
Quote:

Originally Posted by Kevin Sevcik (Post 1252121)
On the topic of inspectors giving more detailed and exacting inspections to robots that "stretch the rules" regarding bumpers:

Do you inspectors actually have differing levels of inspection for different robots that you like or don't like? Are you actually in the habit of giving some robots a cursory inspection while going over others with a fine tooth comb? If so, what exactly is your reasoning for this? I'm curious, because I can't think of any reason to do only a cursory inspection on an uninspected robot. Unless you've worked with a team, you can't possibly know how well that team knows the robot rules. I've run across some very veteran teams that have missed things on inspections. And I've run across some LRI's (myself included) that have skimmed the rules and missed a detail or two. I'm pretty sure it benefits everyone to treat all robots the same and give everyone a thorough inspection.

So again, why exactly are you giving some robots less than a thorough inspection?

If there is a team at the regional that I "like" or "don't like", I don't inspect them - inspectors have to be impartial, so we don't overlook things. As LRI at events, I have to like every team.

No team gets a cursory inspection - every team gets the full inspection. Some teams may be given a harder time, however... You'll treat a rookie team differently than you do a Hall of Fame team - There are different levels of expectations. Besides, it's fun finding issues with those great teams :p

dtengineering 24-03-2013 22:47

Re: Bumper Restrictions
 
Quote:

Originally Posted by Kevin Sevcik (Post 1252121)
On the topic of inspectors giving more detailed and exacting inspections to robots that "stretch the rules" regarding bumpers:

Do you inspectors actually have differing levels of inspection for different robots that you like or don't like? ...

Prior to competing in robotics, I led a high school electrathon race car team. While discussing vehicle tech inspections with a high school drag race team, the high school drag racing coach told me about the importance of washing and polishing the car before tech inspection. The first benefit was that it made sure that everyone went over the car carefully, but the second benefit, as he saw it, was more significant...

"When the inspector approaches the car, from fifty feet away, they can see that it shines. They can see that we take pride in the car and care about little details. By the time we pop the hood and they look at the clean, shiny engine, they are already thinking 'this team has it together'!"

Did they still get inspected? Yes. Did they still have to meet all the rules? Yes. But the difference was that the inspector expected them to pass from the moment they laid eyes on the car.

It probably shouldn't make a difference... but we're all human and all subject to 'first impressions'. Thankfully FRC has some good processes in place to help ensure a level playing field... the inspection checklist, a well-developed set of rules, and a good Q&A system. Perhaps more importantly is that there is one Lead Robot Inspector at each event who works to ensure uniform inspection processes and correct rule interpretations.

So I think I speak on behalf of many inspectors when I say that we look for the same things on every robot... but that the inspection can go much more quickly when teams have clearly met all the criteria and laid it out in a logical, tidy, organized way for everyone to see, rather than having a tangled mess of unlabled wires jumbled together with pneumatics lines buried underneath an opaque panel.

The goal, after all, is to see everyone compete, with a safe, reliable robot that meets all the rules.

But you already know all that... and I get the point that you're making that everyone should have the same "level" of inspection... I think the point that the previous inspector was making was that just as teams can do things to make inspection go efficiently, there are things that they can do that make it take longer.

Jason

Roger 25-03-2013 10:36

Re: Bumper Restrictions
 
Quote:

Originally Posted by Jaxom
...when teams don't know some of the rules, they tend not to know others. ...

Introducing the Van Halen contract and the no brown m&m's clause. Not because they didn't like them, but if you didn't read and comply with that tiny part of the contract, you might not have read the part that their stage production weighs several tons and could sink your stage. As lead singer David Lee Roth said in the Snopes link:
Quote:

So, when I would walk backstage, if I saw a brown M&M in that bowl . . . well, line-check the entire production. Guaranteed you're going to arrive at a technical error. They didn't read the contract. Guaranteed you'd run into a problem. Sometimes it would threaten to just destroy the whole show. Something like, literally, life-threatening.

Kevin Sevcik 25-03-2013 18:35

Re: Bumper Restrictions
 
Thank you for all the well thought out replies. I'll admit the "cursory" wording was stretching things a bit. My primary concern was with the appearance of bias in this post:
Quote:

Originally Posted by IndySam (Post 1251911)
The bumpers are intended for protection and identification. I don't much like when teams start stretching the rules for some tactical advantage.

Pay heed if I am inspecting (or many other inspectors I know) your robot and you are lawyering or stretching the rules you better have a perfect robot in every other respect because you are going to get the most thorough inspection ever.

It seems like the opposite of the effect dtengineering is pointing out. An inspector notices something that rubs him the wrong way, and suddenly he's expecting to find other things wrong and is looking in much more detail for anything, however small, that might be out of spec. Or atleast that's the way that reads to me.

I ascribe to the philosophy that the inspectors are there to verify that teams are legal to compete and help teams get legal if they're not. Comments like the above don't really fit that notion and cast inspection as an adversarial process with teams trying to get away with whatever they can and inspectors trying to catch them at it. Which leads to unnecessary conflict, stress, and nitpicking interpretations of the rules.

For instance, we had an inspector once that wouldn't take our word that our home depot 12ga THHN wire was 12ga. He declared it felt too thin and wanted to see the labelling buried in our robot. After snipping a sample from our spare wire he declared it the thinnest 12ga he's ever seen. He then went on to criticize our abbreviation of our school name BTW-HSEP, declaring it could mean "By The Way, He Sucks Early Peaches". And when we started writing the full name in smaller letters (Booker T Washington and the High School for the Engineering Professions), he declared that it was neither proud nor prominent. At which point I flipped the sign over and scribbled the name on the back just to make him happy and get my kids on the field. This kind of madness and stress is what comes of couching inspection as an adversarial process. Bayou addressed the issue when we filed a complaint, to their credit, but I'd really rather it hadn't happened in the first place.


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