Bumper Material

[Tom Bottiglieri]

Originally Posted by Michael Hill

Why not use the recommended bumper material like everyone else? I'm surprised FIRST hasn't put the hammer down on the exact material that must be used (rather than recommended).

While Cordura makes for good luggage, it makes for terribly boring robot matches when half the field is friction pinned for the entirety of the match.

[Michael Hill]

Originally Posted by AdamHeard

They are following the rules EXACTLY. They are using rugged, smooth cloth.

Nothing wrong here at all.

I'm not saying they aren't following the rules.

Originally Posted by Abhishek R

What's wrong with engineering better bumpers?

Are the bumpers really doing their job better? Do they protect your robot any better than bumpers made from the standard material? The intent of the bumpers weren't to make it easier/harder to pin people. The entire intent was so that your robot (and mine) were better protected against collision.

[Abhishek R]

Originally Posted by Michael Hill

I'm not saying they aren't following the rules.



Are the bumpers really doing their job better? Do they protect your robot any better than bumpers made from the standard material? The intent of the bumpers weren't to make it easier/harder to pin people. The entire intent was so that your robot (and mine) were better protected against collision.

On the other hand, does this different fabric protect the robot any less?

[Michael Hill]

Originally Posted by Abhishek R

On the other hand, does this different fabric protect the robot any less?

I know we're talking semantics, but that's a different question.

I would argue that the reason for the leeway in the bumper material rules is in the case a team isn't able to obtain the exact material specified, not to provide a means of gaining an advantage.

[Electronica1]

If you were to run a four piece bumper system, could you just have the higher grip fabric on the front and back bumpers so you can play defense, and have the slick fabric on the side bumpers to get out of defense and friction pins?

[nuclearnerd]

Has anyone used Silicone fabric spray (used to reduce friction in sewing) on their bumpers? I believe it would still meet the letter of the rules (it wouldn't make sense that you could buy treated fabric, but couldn't treat your own).
http://www.nancysnotions.com/product...icone+spray.do

[Abhishek R]

Originally Posted by Michael Hill

I know we're talking semantics, but that's a different question.

I would argue that the reason for the leeway in the bumper material rules is in the case a team isn't able to obtain the exact material specified, not to provide a means of gaining an advantage.

Oh OK, I see your point. I think of it as minimizing a side effect of the bumpers. While they are meant to protect the robot, they introduce a new flaw in a robot inadvertently. It's like another challenge teams have to overcome.

Also I think the recent surge in defensive play and the need for speed and maneuverability have contributed to this. Some teams have mechanically adjusted for this with either omni or caster wheels, while others have looked to new frame shapes to avoid direct contact or low friction bumpers, especially teams that use tank drives.

[kevincrispie]

Originally Posted by Michael Hill

Why not use the recommended bumper material like everyone else? I'm surprised FIRST hasn't put the hammer down on the exact material that must be used (rather than recommended).

In terms of whether teams should just use the recommended material because that is what is recommended, I would respectfully disagree. Arguably, the recommended bumper material follows the rules less than these other materials. The rules specify that a smooth and rugged material must be used, and the colors must match those of the FIRST logo to a reasonably astute observer. Having a lower coefficient of friction means that these fabrics are smoother than Cordura. As I mentioned before, we also tested the fabric to make sure it was suitably rugged. Multiple smooth fabrics we tested out we decided against using because of this requirement. We feel we have found a solution that is well within the rules that also gives us an advantage, which is really how it should be.

Now, if someone decided to take this another way, and use fabric that had more friction instead of less, that would be a bit more of an issue. At some point, it ceases to be a smooth material and starts becoming something that you design to deliberately catch on other robots. I have a feeling FIRST would rule against something like this.

Another note: in terms simply using the recommended fabric, it is clearly stated in the rules that it is a recommendation, not a requirement, which could change of course. However, if teams were to just do as recommended, there would be much less innovation and thoughtful design in FIRST. There are certainly other teams that use alternate bumper fabric, but the teams I mentioned (1114, 2056, 1678, 1717, 254) are all amazing teams. They have seen a part of the rules (arguably a loophole, though I think not) that they can use to field an ever more competitive robot. Before now, not many teams have even considered bumpers or bumper fabrics an area for innovation. Good teams always find ways to innovate. They work to find creative solutions to real problems, in this case the large amount of friction pins in a wide open game. People might not like it, but I see it as a way to create a better design in a creative way.

I would actually argue that having a smoother bumper material can result in benefits for safety. Less robots caught on other robots and on field elements smooths out gameplay and makes it harder for other robots to use their bumpers as a wedge to get under other robots. It's hard to tell whether it would result in dramatically safer matches, but overall it could be good for FIRST to have more lower friction bumpers out there.

[Mark Sheridan]

Originally Posted by Tom Bottiglieri

While Cordura makes for good luggage, it makes for terribly boring robot matches when half the field is friction pinned for the entirety of the match.

I agree, FIRST as a whole would be a lot more fun if more teams used slick bumpers. Cordura should not be the gold standard of bumper material. It should be ballistic nylon, sail cloth or equivalent. Watching pinning is very boring and not inspiring.

[Nate Laverdure]

Originally Posted by kevincrispie

We also experimented with using [lubricant] on our bumpers... However, we'd likely need to get some sort of Q+A ruling to do that to be safe, as it becomes a user applied material to the fabric.

This one's a real stretch. Even if you can find a way to overcome the R21 problems (BUMPERS must be constructed in accordance with Fig 4-8), you still face this issue:

Originally Posted by R17

Lubricants may be used only to reduce friction within the ROBOT. Lubricants may not contaminate the ARENA or other ROBOTS.

I know this rains on everyone's parade.

[kevincrispie]

Originally Posted by Nate Laverdure

This one's a real stretch. Even if you can find a way to overcome the R21 problems (BUMPERS must be constructed in accordance with Fig 4-8), you still face this issue:

I know this rains on everyone's parade.

To be fair, we did this testing before the season even started, and made the decision not to use anything before the rules came out. I know other teams have tried to use sailkote in the past, but we wanted to collect data on what the effect would be. It was mainly for experimental purposes. I probably should have phrased it better.

Asking the question on the Q+A would likely result in a ruling against sailkote, so asking the Q+A "to be safe" wasn't exactly the right choice of words. That we would ask the Q+A before proceeding is probably a better description of how we would treat the situation, if it ever came up.

[nuclearnerd]

Originally Posted by Nate Laverdure

This one's a real stretch. Even if you can find a way to overcome the R21 problems (BUMPERS must be constructed in accordance with Fig 4-8), you still face this issue:

I know this rains on everyone's parade.

Would you say a solid lubricant contravenes that rule? A silicone or teflon spray dries hard and does not transfer to other objects. If you still object, be sure none of your bumper materials have stain-resistant treatments from the factory which amount to the same thing.

[EricH]

Originally Posted by nuclearnerd

Would you say a solid lubricant contravenes that rule? A silicone or teflon spray dries hard and does not transfer to other objects. If you still object, be sure none of your bumper materials have stain-resistant treatments from the factory which amount to the same thing.

For the purposes of FRC rules, it's not the same thing at all. If the stain-resistant treatment is applied at the factory, it is part of the rugged, smooth cloth, and thus perfectly legal (given that all other applicable rules are followed).

If you apply it at your shop, it is NOT part of the rugged, smooth cloth, it is an added product that may or may not be legal depending on what the GDC has ruled.

It's like using a metal hose from the compressor to the first fitting. If a team decides to buy a metal pneumatic hose/tube (larger than allowed tubing, most likely), attach it to their compressor, and try to pass inspection, chances are it'll be ruled an illegal part. HOWEVER, if that same metal hose comes with the compressor and the MANUFACTURER says that the compressor needs to be used with that hose, then it is ruled part of the compressor! (And yes, the GDC did make that exact ruling in a Q&A--though not in the same words.)

The difference is slight, but it makes a huge difference in whether you're playing or not.

Oh, and on the solid lubricant: I would consider it to be in violation if the GDC had ruled that bumpers had to be constructed per the rule and that adding stuff to the cloth to modify its effects was illegal (as I recall, they made enough statements that tended to go that way that I'd be pretty comfortable with a "no pass" call, probably with a side of "LRI to confirm"). Remember, though, what I said earlier: If the cloth comes that way from the manufacturer, it's legal (unless the GDC has ruled otherwise).

[Nate Laverdure]

Sounds like a great new revenue stream for the AndyMark Fabrics Division.

[nuclearnerd]

Originally Posted by Nate Laverdure

Sounds like a great new revenue stream for the AndyMark Fabrics Division.

Exactly. Placing the division at "comes that way from the factory" is silly (although I recognize that may be the way it is). In that case I would happily have my local fabric store apply the coating, then offer it back to me as a "commercial part". It would be counterproductive to FIRST goals to have rules that discourage in-house fabrication but allow purchasing the same item from 3rd parties.

Please note that this question is purely academic for this year - We didn't modify our fabric at all. I'm thinking about next year.