Robot bumpers

[EricLeifermann]

What is your teams reason for using the official FIRST bumpers?

[BlondeNerd]

Protection! The bumpers keep our bot from being damaged and damaging other bots. Just think, which is worse: being wacked with a pool noodle or being wacked with a piece of aluminum?

[Justin M.]

Bumpers don't allow you to use extra weight. Only the bumpers are weighed and have to be built to FIRST specs.

We use them because....why not?

[MattLi]

Originally Posted by Justin M.

Bumpers don't allow you to use extra weight. Only the bumpers are weighed and have to be built to FIRST specs.

We use them because....why not?

Please explain. I pulled from this that you're saying the bumpers are included in the weighing of your robot. I was almost certain that they're not included.

[EricH]

Originally Posted by MattLi

Please explain. I pulled from this that you're saying the bumpers are included in the weighing of your robot. I was almost certain that they're not included.

They aren't. See the rules on bumpers in Section 8. Unless, of course, you use custom bumpers, in which case you must include them both in weigh and in size.

[Justin M.]

Originally Posted by MattLi

Please explain. I pulled from this that you're saying the bumpers are included in the weighing of your robot. I was almost certain that they're not included.

No, I was correcting his statement that bumpers allow you to use extra weight on your bot, as an advantage. Since the bumpers need to be built to FIRST specs, and are weighed separately, you aren't getting a 15lb weight gain on your overall bot, ruling out using bumpers as an "extra weight" advantage.

I highly recommend to newer FIRST teams to build the bumpers. Like I said before, why not? They aren't weighed or measured with your bot...all it does is give you an advantage. If you think about it, robots accused with "ramming" your bot will get a yellow flag, etc. but remember that just because they were penalized, doesn't make the hit not happen. If it happens, it happens. If that hit puts your bot out of commission, then your team winds up more screwed than the ramming team. If you have bumpers, you have a big saftey net for rammers. That way, if someone rams you really hard, they get a yellow flag and your bot doesn't even get scratched .

In 05, the year before the bumpers were implemented, I've seen some bots with broken/bent/cracked chassis, destroyed wheels, broken chains, bent shafts, blown-up gearboxes, the works. All as a result from ramming. The bumpers will definitely protect your bot from these things better than a bot without them.

[Gdeaver]

I would encourage teams to look at the bumpers as a structural element. They can be more than protection and weight. Even a strong frame can take damage from a point impact. Hitting a wall is not the same as another un-bumpered robot hitting your unbumpered robot at high speed. Our 2006 robot has a nasty dent in the frame from ramp riot.

[MattLi]

Originally Posted by Gdeaver

I would encourage teams to look at the bumpers as a structural element. They can be more than protection and weight. Even a strong frame can take damage from a point impact. Hitting a wall is not the same as another un-bumpered robot hitting your unbumpered robot at high speed. Our 2006 robot has a nasty dent in the frame from ramp riot.

What would this structural element be? No matter how I think of it bumpers always strike me as either weight, protection, or stability.

[Ian Curtis]

Originally Posted by Justin M.

No, I was correcting his statement that bumpers allow you to use extra weight on your bot, as an advantage. Since the bumpers need to be built to FIRST specs, and are weighed separately, you aren't getting a 15lb weight gain on your overall bot, ruling out using bumpers as an "extra weight" advantage.

In 05, the year before the bumpers were implemented, I've seen some bots with broken/bent/cracked chassis, destroyed wheels, broken chains, bent shafts, blown-up gearboxes, the works. All as a result from ramming. The bumpers will definitely protect your bot from these things better than a bot without them.

In regards to the first paragraph, I do not understand what you are saying. Bumpers are allowed to weigh up to 15 pounds, with an average of no more than 3 ounces per inch. The 15 pounds is on top of whatever weight class you choose. If my robot weighs 120 pounds, and I use bumpers, I now have a 135 pound robot. They are a weight advantage. If you don't use bumpers, you don't get that weight. <R37> clearly explains this.

Also, bumpers WERE implemented since at least 2004, but the rules were much looser and there was less of an advantage to be gained by their use.

[Madison]

Often times, when people discuss the 'weight bonus' that comes with using bumpers, what they're talking about is the benefit that an additional 15 lbs. has when calculating the force of friction between the playing field and your robot's traction surfaces.

Force of friction is calculated as some coefficient of friction (mu) times a normal force. In this case, that normal force is the weight of the robot, so a higher weight provides for a higher force of friction.

More friction makes it more difficult for others to push your robot when it's standing still. The added weight doesn't allow for any benefit to mechanism design or robot function, however.

[EricH]

Originally Posted by iCurtis

Also, bumpers WERE implemented since at least 2004, but the rules were much looser and there was less of an advantage to be gained by their use.

Custom bumpers have been allowed for years and years, subject to the weight limit of 130 or 120 or whatever the limit was and size rules similar the the "standard" bumper. After 2005, the wedge was outlawed and the standard bumper introduced, and now we have bumpered robots everywhere.

On structural element: yes, is it possible. Run your drive similar to, say, 968 in '05 and '06, then use the bumper as an outer frame rail without the weight of one (just don't leave it on for inspection, and your robot better run without the bumper.)

[Pavan Dave]

We will probably be using the bumpers because it is safer. It makes our robot able to take bigger hits and lets us worry a little bit less than if it was metal to metal. From last year's robot I am thankful that we had at least corner bumpers because otherwise there were some blows that would have hurt us much more than a dent.

Also when you are talking about protection that also means weight because a low CG is protection if you really think about it.

Pavan.

[Charger_07]

bumpers saved our robot last year since the judges decided to ignore other teams ramming

[Dan Petrovic]

We use them for the weight and protection.

Plus there's the wider footprint so robots are more stable.

[PDF32100]

WELLLLLLL with our new frame we put it at full speed with 4 motors(just to try out) and rammed it to the wall a few scrathces but no damage at all but we might still use bumpers ... ITS SMART IF IT DOESN"T AFFECT U IT ONLY HELPS U DEN USE IT