No matter what the ruling is, I will be sure to start making custom PET parts that is under 3”x5” by stacking 20 of those PET sheets together
I’m not saying it is. In fact, I was saying that I disagreed with DRow’s interpretation in a few key places.
Uh no, actually, the “functionally identical parts” rule doesn’t apply to everything, only to specific fasteners and small hardware.
Perhps. I may have had a hard time following along.
I would say that this line of reasoning is off. I agree:
It is clearly a part meant for robot construction
I disagree that:
Nothing would suggest that it would count against the plastic limit in <R9>
The rule was written before the product was announced, therefore the only type of plastic allowed on the robot when the rule was written were “custom” pieces, cut as-though from a single 12"x24" sheet of plastic.
I think the most reasonable interpretation of R9 would be simply replacing “custom plastic” with “plastic”. Are there other “reasonable” interpretations? Possibly, though I don’t buy them. And planning a robot or major component around an assumption of the ability to use unlimited amounts of VEX PET Sheets seems far more risky than I would be comfortable taking. But others have other risk tolerances, so you do you…
The only other interpretation I could understand as “reasonable” that would permit “unlimited” amounts of the “PET Sheets” would be if those sheets were not “customized” (e.g. not cut as it would then be “custom plastic”). But, again, I don’t buy this line of thought.
Well, another (absurd) possibility exists for unlimited “PET Sheets” as a material - to utilize the PET Sheets in strips no thicker than 1/4" to qualify as a “rope”.
Can we at least agree that as the rules are written now, the PET sheets and the Polycarbonate sheets should be treated the same?
To clarify for future readers, plastic is also on the list of non-VEX things you can use(as of this post). While R7 is generally considered “the list” of non-VEX parts, R9-R12 work in addition to R7, not as clarifications of R7. Vex only sells polycarb, but most non-shattering plastics are legal as long as the amount and thickness conforms to R9. There is no way to separate ““official”” vex polycarb sheets from a polycarb sheet I can buy at the hardware store. They are not laser marking them like diamonds or anything.
Be that as it may, for a significant portion of last season, the “identical” robosource standoffs were illegal, simply because they didn’t originate from VEX.
Yes.
Given that, I do not understand how one could reasonably hold that an unlimited amount of Polycarbonate is now permitted, given the existence of R9.
Can one make a reasonable argument that the arbitrary restriction on how much plastic one can use on a robot is overly constraining (similar to prohibitions on 3D printed parts)? Of course. But any competition format (and engineering in general) imposes constraints - some rational, some not.
Because of “custom made” being poorly defined. A reasonable person wouldn’t call the PET sheets “custom made”, and therefore they shouldn’t count under R9. We agree that the PET and the Polycarbonate need to be treated the same, so under this logic R9 does not apply to the Polycarbonate either.
Prior to this product’s release, only “custom made” polycarbonate was allowed. Surely you don’t believe that unlimited amounts of unmodified polycarbonate was allowed in Tipping Point, or in Spin Up prior to this particular product’s release?
Again (and trying not to pick on you), I fear that the Internet’s definition of “common sense” and the GDC’s are wildly at odds.
As a matter of fact, I do. I would never have come to this conclusion without the existence of the PET sheet product, but now that it exists, it is my opinion that the rules have always allowed unlimited polycarb, provided that polycarb was bought directly from VEX, with an additional 12x24 sheet of non-shattering plastic (delrin or other non-poly, not-from-vex, plastic) allowed as well.
Again, I think your definition of “common sense” is wildly at odds with the GDC’s. If this engineering thing doesn’t work out for you, consider law school.
Good luck convincing a Head Inspector that a robot with 100 uncut sheets of 12x24 Lexan used in a functional manner is legal.
As a matter of fact, the event staff in my region are of the opinion that this whole things is rather funny, and until the GDC clarifies I believe yes, they would be willing to humor me.
I disagree. I believe the ready made PET sheet parts are not included in the custom plastic allocation. Like all other VEX parts that are legal for use, there would be no limit on the quantity of these used in a robot.
I believe the polycarb sheets are a supply item provided by VEX as a convenience and service to teams. They are distinct from a VEX “part” in that they are not intended to be used “as is”, but are intended to be modified by the user to create a custom and legal part (similar to pneumatic tubing, smart cabling stock, etc.). There is a quantity restriction placed on the use of this material in the manual, and it is up to teams to stay within that constraint in order to be competion legal.
The above represents my Common Sense™ interpretation of the rules, and it is how I believe an official Q&A on the question will/should be answered.
I also believe that the Common Sense guidine is the biggest landmine in the manual, and am not shocked that others have a different opinion than me, nor would I be surprised if the GDC resolves this in a manner other than what I suggest.
More practically, how would you incorporate the sheets in a useful way without modifying them? They could only be used parallel to the floor in one direction and sloped at close to 45 degrees (or bent significantly) to fit in size. Then there is the issue of fastening to the robot without using tape, velcro or making any holes.
If I was to purchase a 36" x 72" polycarb sheet from VEX and bend/fold it in a way such that it all fit inside my 18" cube without being cut, would that qualify as a “custom part” under your interpretation? Would it count against the limit?
Similarly, if I were to cut, drill, or otherwise modify a PET sheet, would it then be considered “custom” and count against my limit?
That would be a custom part and it would not be legal because it would be larger than the allowable 12"x24" total amount allowed.
There is nothing in the rules that indicates modifying the PET sheets (or most other parts) is not allowed, so that would be legal. It would still not be a custom plastic part cut from up to 12"x24" of legal plastic. Gears, spacers, sprockers, chain, and wheels are made of plastic as well. Cutting or modifying them does not suddenly make them fall within the custom plastic limit in the rules.
I agree that someone could modify a VEX PET part to such an extent that it would be difficult if not impossible for an inspector to distinguish it from allowable plastic limited by . As an Event Partner who might have to help an inspector or head ref make a determination, I would likely say that if the PET sheet has been modified so significantly that it is no longer possible to distinguish if it came from the original VEX part or a similar sheet of bulk PET, that it should be counted towards the 12"x24" plastic allocation. I think the likelihood of that happening is very remote, though, as I can’t see someone paying a premium for the specifically designed PET sheet parts only to cut them up into unrecognizable components.
I also think this whole question is splitting hairs and is unlikely to ever become a real issue. I honestly can’t think of any circumstance in the scores of VEX competions I have been involved with where a robot has had to be unduely scrutinized for using too much plastic sheeting. Out of size? Yes. Wrong thickness? Yes. I’m not saying it hasn’t happened or can’t happen, but I think it is one of those extreme edge cases that rarely if ever comes up.
I understand that my reasoning may not entirely make perfect sense to you, but that exactly illustrates my point of the challenge of relying on “common sense” as a benchmark for some of the rules in the manual.
It is clear due to the differing opinions already expressed on this topic in this and other threads that a Q&A will inevitably be asked and answered, and the GDC will be forced to come up with a specific clarification that will inevitably align with some people’s understanding and go contrary to others. Until a ruling or manual update is put in place that shows my interpretation of the rules to be incorrect, any event that I help run I will subscribe to what I believe is the “common sense” understanding of the rules with regards to this question. If, before I am so humbled, I am so lucky as to have @Sylvie compete at one of my events with an origami bot, I will happily explain how a 36"x72" piece of VEX supplied plastic on one robot is outside both the spirit and letter of the rules and that the bot will not pass inspection.
are thé polycarbonate sheets only able to be cut using laser cutters?