My team for the past two years has used the slick bumper material sold by AndyMark due to my team’s strategy always being offensive, and wanting to slide past robots easier. We have had lots of issues by the end of the season (2016 and 2017) with our bumpers having nasty gashes and fairly bad rips. Is it legal to combine bumper fabric? Ie. sewing or adhering the slick bumper material to one side of a thicker and (most likely) more durable bumper material? And if so, has anybody done this before, and have it work as it should?
Covering a more durable fabric with the slick bumper fabric should be okay.
In the 2017 game manual it says that the bumpers must “be covered with a rugged, smooth cloth. (multiple layers of cloth and seams are permitted if needed to accommodate R26, provided the cross section in Figure 8-5 is not significantly altered).”
Multiple layers are fine for the flipping type of bumpers with reversible colors, so I don’t see why there would be an issue with a fabric underneath what you already use. I’d recommend using the normal bumper fabric on AndyMark underneath. It’s held up perfectly for our team.
Besides, if you get a tear in the slick fabric they’ll still be the right color.
Also per 2017 rules, bumpers count towards CAWst so factor that in as well*.
*This is of course subject to the old LRI-a-roo.
You correctly quoted R29 part D, but I think it worth emphasizing part of it:
be covered with a rugged, smooth cloth. (multiple layers of cloth and seams are permitted if needed to accommodate R26, provided the cross section in Figure 8-5 is not significantly altered).
R26 states:
Each ROBOT must be able to display Red or Blue BUMPERS to MATCH their ALLIANCE color, as assigned in the MATCH schedule distributed at the event (as described in Section 10.4.1 Schedule). BUMPER Markings visible when installed on the ROBOT, other than the following, are prohibited:
So the intent, and the letter, of R29 part D is to more easily allow switching colors, not to allow multiple layers of fabric to be used simply to support each other. I wouldn’t necessarily expect it to be allowed, without asking on the Q&A ahead of time.
For my part, I would think using two layers - a rugged layer and a layer designed to be smooth - would give a team an advantage that isn’t allowed in the rules. It allows them to skirt around the “rugged” requirement in order to gain an advantage with a smoother fabric that wouldn’t otherwise handle game play.
Do you have a basis to support claiming that it isn’t allowed in the rules? Because otherwise, LRI-a-roo
I quoted my basis - R29 part D specifically states multiple layers are permitted if needed to satisfy R26. It doesn’t provide for any other situations where multiple layers are allowed. Whether or not your inspector notices or thinks about it is another question all together. But even given that, being told by your inspector to remake your bumpers while at an event is something best avoided.
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So I’ll bite… Your claim is that it violates the idea that the bumpers with slick fabric aren’t rugged but what if my slick material is the same slick material that AM now sells or its the same slick material that another team is using at the event? Should all teams with slick material have to redo their bumpers or only the team using the slick material with another material layer underneath? Can I double up my slick material?
Multilayer fabrics exist and are sold as continuous pieces of rugged, smooth cloth. Does this change your interpretation?
Going in a slightly different direction, can we discuss whether there is even a brand/type/source of slick fabric that actually has the desirable and required characteristics for a typical FRC game? We used “sailcloth” (purchased from Sailrite) for the 2016 game, and wished that we hadn’t. It was so brittle!
We have used sailcloth for the past two years and loved it. Our stuff came from a very generous small company at the NC Outer Banks that happened to respond to an email asking for advice about suitable sailcloth material… he sent some samples and hooked us up with some rolls that should last for many more years. No idea what the brand is… I’ll post it if I can find it.
I’m claiming your logic as stated was a stretch. If having two layers of fabric on a single bumper facilitates my properly displaying Red or Blue bumpers in any way and does not violate the cross-section I would assert that the specific role the two layers plays is not for inspectors to decide.
You’re reading in that the R29.D line is exclusively for reversible bumpers but since I don’t see that in the rules I’m asking you to justify your position that it is.
As it stands as long as the team attests that the dual layers of fabric are required to meet R26 R29.D should allow them to do so provided both layers are rugged and smooth cloth.
I would support this claim based on the number of fabric rips I’ve had over the years which, when patched, end up looking horrible. Dual layers of fabric may help bumpers remain clean looking for longer or, at the least, facilitate better looking patches. While appearance may not matter to some teams to others it is an important aspect of this competition.
The OP’s description of “nasty gashes and fairly bad rips” would seem to indicate that the chosen fabric wasn’t rugged enough for competition. It’s not a question of slickness or roughness - it’s one of using multiple layers in order to make a fabric that wouldn’t be legal on its own more durable. If a team tells me they need 2 layers because one layer isn’t rugged enough, then I think that’s a pretty clear violation of R29 part D.
Having used Cordura brand fabrics for years on bumpers (which, if I recall, were the recommended fabric for a few years) and still experienced many nasty gashes and bad rips due to impacts with appendages… What IS durable enough? There’s a lot of energy in these collisions, in the case of bumper to bumper collisions it’s usually fine. But when an appendage hits a bumper it tends to tear or rip because metal on fabric…
Ninja Edit - I will concede, some of that is from time on 125 where we played WAY too many matches.
We attempted to use the slick bumper fabric in 2016, it was very fragile and tore frequently, as well as being not very slick. We took a trip to Joann’s fabric and managed to find some much better fabric that we used this past year as well, ended up with a few tears but it is smooth and much more durable. I highly recommend a trip to your local fabric store and finding something that might fit your needs a little better. It can be much cheaper too!
The rules say covered in cloth, provide a specific cross section that shows only 1 layer of cloth, and provide an exception that allows for multiple layers in certain circumstances.
How can you read that as saying multiple layers are also allowed in other circumstances?
As it stands as long as the team attests that the dual layers of fabric are required to meet R26 R29.D should allow them to do so provided both layers are rugged and smooth cloth.
If it’s actually needed for switching colors, then it’s legal per the rules. But I’m having a hard time picturing a case where you would use one layer to support another and be able to argue with a straight face that it’s actually to assist with switching colors.
I would support this claim based on the number of fabric rips I’ve had over the years which, when patched, end up looking horrible. Dual layers of fabric may help bumpers remain clean looking for longer or, at the least, facilitate better looking patches. While appearance may not matter to some teams to others it is an important aspect of this competition.
The rule doesn’t say anything about dual layers being used to help make things look better. And, quite frankly, most bumper covers that are out there, and some reversible bumpers, don’t look all that good in the first place.
Each ROBOT must be able to display Red or Blue BUMPERS to MATCH their ALLIANCE color, as assigned in the MATCH schedule distributed at the event (as described in Section 10.4.1 Schedule). BUMPER Markings visible when installed on the ROBOT, other than the following, are prohibited:
Explain where it says the bumper has to switch? It says I have to be able to display EITHER color. You’re reading words into it which simply aren’t there to justify your claim.
Red on Red fabric would in fact enable that bumper to display the alliance color as would Blue on Blue.
Nobody mentioned covers. I’m talking two sets of fixed color bumpers with two layers of durable cloth to minimize the visibility of rips and tears. I’d assert minimizing the amount of noodle visible after a rip mid match aids in R26.
A second layer of the same color wouldn’t be needed to display that color. I fail to see how having two layers of the same color can be justified as being needed to accommodate R26, when the first layer alone does that.
If a team tells you they have red fabric under their blue fabric in case they need to switch bumper colors but then has a second set of bumpers that has blue fabric under their red fabric in case they need to switch bumper colors is this a violation of the rules? There is no limit to the number of sets of bumpers you can bring.
If said team arrived at that design because their outer layer of fabric is ripping frequently, I suspect they’ll run into issues with other rules regarding bumper color first.
And I’ve explained it to you at least 3 times now and I’m tired of it.
You’re arguing against something with questionable evidence that provides 0 competitive advantage (unless you count the extra fabric weight, which is silly given there’s an upper limit on bumper weight that most teams are nowhere near anyway). I’m arguing to let teams do something to improve the aesthetics of their bot if they so choose.
We can agree to disagree and if it ever becomes and issue argue it out then and there.