Bumper Restrictions

[IndySam]

Originally Posted by Gregor

I don't think this is fair. If team's builds their bumpers within the rules, and you don't agree with the rules, why should the team get a more difficult inspection?

It doesn't matter if you like it or not, if they comply with the rules, it is not your position to judge.

I'm not talking about being within the rules, I'm talking about stretching them to the breaking point. Mounting a 10 pound steel plate to a bumper that has no real practical reason is violating the spirit of the rules.

And as far as your second point, in fact, is is the inspectors job to judge if a team is complying with the rules.

[Gregor]

Originally Posted by IndySam

I'm not talking about being within the rules, I'm talking about stretching them to the breaking point. Mounting a 10 pound steel plate to a bumper that has no real practical reason is violating the spirit of the rules.

And as far as your second point, in fact, is is the inspectors job to judge if a team is complying with the rules.

Stretching the rules is still complying with the rules. Until it is explicitly illegal to add weight just to add weight (assuming all other bumper rules are met), giving a team a harsher inspection is against the point of inspection. Is the point of inspection not to get all teams on the field, while ensure that they comply with all the rules?

It is the inspector's job to inspect the robot, they inspect the robot for compliance, end of story.

[Jaxom]

Originally Posted by Gregor

Stretching the rules is still complying with the rules. Until it is explicitly illegal to add weight just to add weight (assuming all other bumper rules are met), giving a team a harsher inspection is against the point of inspection. Is the point of inspection not to get all teams on the field, while ensure that they comply with all the rules?

It is the inspector's job to inspect the robot, they inspect the robot for compliance, end of story.

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.

[Racer26]

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.

[Jon Stratis]

Originally Posted by Racer26

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!

[Gregor]

Originally Posted by Jaxom

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]

Originally Posted by Gregor

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]

Originally Posted by Gregor

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:

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]

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]

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

[apples000]

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]

Originally Posted by Jaxom

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]

Originally Posted by apples000

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]

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]

Originally Posted by Kevin Sevcik

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.