Please reference rule <R35> quoted in its entirety below for this post:
<R35> Adhesive backed tapes are NOT allowed except as follows:
• Velcro tape, any hook and loop tape or double-sided sticky foam may be used for attaching
components to the ROBOT.
• Reflective tape may be used with optical sensors in small amounts.
• Adhesive backed tape and labels may be used for labeling purposes on wires, cables,
pneumatic lines, etc.
• Electrical tape may be used as an electrical insulator.
Our team is using plastic cam chain tensioners exactly like those found in this post. In an effort to increase the friction between the end of the plastic cam tensioner and the metal frame and help keep the tensioner from moving we would like to put some sort of “donut” of grippy material between the plastic tensioner and the frame. The obvious solution is to cut a “donut” of “grip tape” like you use on steps or skate boards to increase traction, however, this would seem to be a clear violation of <R35>.
FIRST tells us not to “lawyer” the rules and try to understand the “spirit” of the rules. My question then is what is the intent or “spirit” of this rule? I understand that FIRST doesn’t want to see a bunch of robots held together with duct tape, however, tape and adhesives are used in millions of properly designed products every day including every automobile manufactured today. Does FIRST have a problem with the tape or the adhesive?
I would think “grip tape” would have lots of uses on a FIRST robot. With all the talk of ramps this year, what would be the danger of having some on top of a ramp to increase traction?
One way we could possibly get around this rule would be “make our own” by just gluing some emory cloth or sandpaper to the frame and/or plastic tensioner but does this violate the “spirit” of the rule? It would not technically be “tape” but I wonder if it would pass inspection. If we can “make our own” then why not just let us use COTS “grip tape” and be done with it?
Are there any inspectors out there that could shed light on how they would view this issue?
This is always a tricky rule, because of the many ways that it can be interpreted. In the past, some Q&A responses and unofficial comments have suggested that tape is defined by how it’s used—the intent of the rule was to avoid teams duct-taping robots together, so they sought to prevent the use of tape as a fastener. At other times, adhesive tape is anything sold as adhesive tape—but this is potentially unsatisfactory, because self-adhesive sheets of a film or paper can perform the same function, and presumably violate the intent of the rule. Similarly, when no descriptive name is given to a product, how narrow does it have to be to be an adhesive tape, rather than an adhesive sheet?
Last year, the standard was pretty much one of usage. Self-adhesive rubber matting, for example, was permitted by Q&A responses, even though it was in effect a tape, and may even have been supplied on a roll.
As I interpreted it last year, tape used as a fastener was definitely not allowed, anything that could be considered tape (but wasn’t necessarily called tape) used as a fastener was similarly not allowed (but admittedly a grey area). Anything sold as tape (i.e. has “tape” in the name, or on the manufacturer’s description) couldn’t be used for anything other than what was explicitly permitted by last year’s equivalent of <R35>. But I allowed things which were similar to tape (like the self-adhesive mat, or non-slip stair tread overlays), but which were not used as a fastener, and weren’t labelled as tape. It’s obviously open to interpretation, but I believe that that satisfied both the letter of the rules, and the intent, as they existed last year. (But it’s an ugly compromise.)
This year, however, the Q&A has ruled against staircase tread tape. It’s not clear whether they’re ruling against it because it’s called/sold as tape, or because it has the properties of tape. When extending that Q&A response to other products, you obviously need to know which sense of the term was intended.
Gluing your own sandpaper would definitely pass inspection (assuming all other rules are satisfied).
Since I designed and fabricated those tensioners, I can tell you that we did not used any sort of grip-tape between the tensioner and the bolt. We make sure to use as large of a washer as we could, to increase the loaded surface area. As long as your contact area on both sides is large enough, these types of tensioners should not slip on you.
If you find that you’re having problems with them slipping, you can always use a “toothed washer” to help grip against the material.
Ben, we have used that same design as well sucessfully, but I did have one question for you. When you torque them down nice and tight after tensioning the chains, the chain seems to make grooves in the Delrin. Nothing a simple readjustment can’t fix but sometimes the forces at work make an even more interesting problem.
Basically, if you only attach the delrin rods on one end, they tend to bend away from what they are mounted on. Just wondering if you had a solution for that or even ran into that problem?
If you don’t get what I mean as of yet, I’ll grab a pic and link it tomorrow or later tonight.
I would suggest that you check into one or two part epoxy paints intended for use on garage floors. These floor epoxies have fine or course grained additives (sand, et cetera) which can be added to the paint before application. This treatment gives the paint a sandpaper texture which should be just as good as the non-slip tapes being discussed here and would be completely legal on a FIRST robot.
Another alternative is cloth backed sandpaper applied with an epoxy adhesive.
Rules are rules. Spend your time coming up with alternative solutions rather than complaining about rules you don’t like.
One way around this would be to “paint” the part with traction paint.
It used on ships and in plants to make a non-slip walkway.
Basically its oil based paint with sand in it.
Any paint store should be able to hook you up with a qt. and a brush for under $10.00.
The further out your chain is from the side wall, the larger the bending forces on your tensioner. So, you either need a bigger/stronger bolt, or you need to reduce the load on the bolt. You can either bring the chain in closer to the wall, or create a wider base on your tensioner. The wider base will help counter-act the bending load in conjuntion with the bolt. We typically use a 1.5" - 2" diameter HDPE rod and if required, we’ll turn down the center of the OD to create a flanged tensioner.
The grooves you’re finding in the tensioner will develop over time. The harder the plastic you use, the better. HDPE, Acetal, Delrin are all good choices. Polypropylene and Teflon are softer, and while they provide excellent low-friction surfaces, they also wear away much quicker.
Thank you for your detailed and insightful reply. It was most helpful. I think this is the crux of my question. I cannot imagine FIRST has an issue with “tape” just because it is long and narrow and comes on a roll and the package says “tape” so I must conclude that for some reason they do not like us using adhesives. While I don’t find any other rule prohibiting “adhesives” I have to wonder why they specifically prohibit it if it is long and narrow and comes on a roll. I am not complaining nor trying to figure out how to legally break the rules, I am simply trying to figure out the intent. As we both stated, I think it is to prevent duct tape robots but with the rule written as it is it always seems to be a sticky area as to what they intend and what is and isn’t allowed in the “spirit” of the rule. If it is wide and flat (i.e. sheet) it is OK but long and narrow (i.e. roll) it is not??? What is wide and what is narrow??? So if we just got a sheet of grip material and cut our “donuts” out then that is OK but if we cut them out of a roll of the same stuff but too narrow then it is not? Seems like a real sticky area there to me. If all inspectors viewed the rule with the same common sense as you do then I don’t see a problem. I am just worried that some inspectors may “lawyer” the rule and take it word for word rather than view it with the intent of the rule and not pass duct tape robots. We have all used stick on sponsor logos and team numbers in the past.
There are, of course, many solutions to the specific problem I presented as an example. The traction paint and star washers are both great examples. Thanks to all for those ideas. BTW: We are using Delrin-AF but you can be assure we will not be using anything that can even remotely be considered “tape”.
My intent was more to discuss the limits and intent of <R35>. I still am unclear why “grip tape” is bad but glued on sandpaper is good. I understand that is the rule, but why? It just seems, well, pointless.
The rule against “tape” goes back to before my first FIRST competition (1995). More than likely, either Dean or Woody had an issue with it or a team abused its use prior to 1995.
Also, the vast majority of “tape” products are meant to be temporary and easily removed while the vast majority of non-tape “adhesives” are not. Temporary implies that the material will come loose from your robot and become attached to other robots or field components.
There are no absolutes in the world and I’m quite certain that almost anyone can find exceptions to the previous paragraph.
Regardless of its history, it has been one of the true “constants” in the rules over the last 13 years. FIRST has been resolute and firm in not allowing tape (other than electrical tape for insulation) on a competition robot and any suggestions of changing this rule have been immediately squashed.
My opinion is that you will have a better chance of seeing custom power electronic circuits or custom motors allowed before you ever see “tape” allowed.
Most veteran teams have become quite proficient in the use of epoxies and other industrial adhesives. You deal with it and move on…
There are many rules that have a very clear and understandable purpose (e.g. you have to display your team number on your robot. Why? Because the referees, other teams, and the audience need to be able to identify you when you compete). They are the way they are for a discernable reason. However, we also have to accept that there are some rules that are the way they are just because that is the way they are.
But a rule does not need to have a detailed, extended explanation behind why it is the way it is. Some do, but some are simply the result of a decision that had to be made at a particular moment, and there is no more extensive reason than that. It is very easy to imagine that at some point in the past while the rules were being written the question was raised “what about adhesive tapes? Do we allow them or not?” There may not have been a particular situation they were trying to avoid. It may have been as simple as “should this be part of the challenge? Can you build a robot without resorting to adhesive tapes?” Without any other extended discussion about why or why not to allow tape to be used, they decided to flip a coin. It came down tails, so no tape allowed.
Why are the dimensions of the robot 28 x 38 x 48/60/72? Why not let the base be 40 inches long? Or limit it to 28 x 28 so it can go through a standard door in either direction? There is no particular reason that it has to be 28 x 38 x 48/60/72. It is just at some point someone had to make a decision about the size limits, and that is what they picked as the constraints to define the problem. I don’t know the entire history of the “no tape” rule, but maybe the tape question was the same. Maybe it is that way because it is that way.
