R12 Clarification Plastic/Aluminum Screws & Nuts

So, with the new R12 update, would aluminum and plastic/nylon screws and nuts be illegal because they are lower weight than Vex steel screws?

It’s still not entirely clear, despite my hopes that the update would have fully clarified this specific issue, but given the wording “functional difference between the two screws”, it seems like they want us to consider the screws in question individually, by themselves, without any context of the entire robot. In which case, a bendy screw could be used in a way a standard metal screw couldn’t, but the weight difference of a single individual screw would not have a functional effect on the robot as a whole.

Confusingly though, they give the specific example of using the flexibility of a nylon screw as illegal, when vex does actually sell plastic thumbscrews which could be used to gain this flexibility if a team so wished to (though I’ve never heard or seen nylon screws used for this reason)

for this reason, I believe that nylon screws should be legal for any application, because you can buy plastic screws from vex, and such nylon screws cannot introduce any additional functionality, regardless of how they are used.


I agree with this post, but going off of the wording of the rule, it shouldn’t even matter if the weight difference between plastic and steel screws has a functional effect on the robot as a whole. The rule specifies a functional difference to the mechanism in question.

For example, if a team made all the screws on their lift nylon, provided their lift would work with steel screws, the effect this would have on the weight of the robot as a whole would be irrelevant in interpreting whether the team has violated R12.

On the other hand, all of this assumes that weight is even considered an additional functionality (I would argue it doesn’t fall into this category), which the GDC has not clarified.


exactly, the rule seems like it wants us to consider the functional effects of the individual screws, not in the context of the entire robot. Unfortunate that the gdc has chosen to not clarify this entirely though, despite the problems with nylon screws at a certain event this season. Was really hoping they’d clear it up for future seasons.


I think the GDC is intentionally leaving this rule vague because they are scared of blanket legalizing stuff that they can’t think of.


Would be great for @VEX_GDC @Sidoti @Jon_Jack @Grant_Cox to elaborate on this


So true.

Minimum word count needs to be met

This man has true bravery, pinging 3 people on the GDC, and the GDC itself. But I didn’t know there were 2 types of screw material for vex. We just use whatever.


But she forgot to ping drow

E: fixed pronouns, my bad

True, but he didn’t want to seal his fate of certain death, just an 85% chance.


It’s more to do with being aware of who is and isn’t involved in those judgement calls?
To my mind the rule is clear: the officials at the event have to ascertain whether the non-vex faster is essential to a function of the robot. If substituting a vex fastener wouldn’t impact its function, then it’s fine. That’s going to be tough in some instances because it might not be obvious and there will be disagreements. I think demanding a tight definition of exactly what would and wouldn’t impact functions that haven’t been thought of yet is asking a bit much. A specific fastener may have the potential to significantly alter a function in some builds and not in others.
But, I’m not involved in those judgement calls.

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The issue with the current interpretation of comodity hardware is a few contradictions and what seems like a tiptoe around discussing weight of hardware.

The Q&A’s in previous seasons about nylon screws explain you can’t use the flexibility of the nylon (which feels wrong as VEX sells plastic screws that would flex),

Lock washers were ruled illegal last season for introducing new functionality, even though you could remove the skirt from a keps nut pretty easily and use that.

And how do you judge #4 or M3 screws, which have no equivilent and are lighter and lower profile, but explicitly legal by the base of R12?

R12 seems to be one of the only rules that has a redbox and Q&A clarification that contradicts the rule itself. Where R12 says

You can use any comercially available hardware

and the rexbox says

Except for…

Because the rule is structured this way, it’s not unreasonable to say #4 or M3 screws are illegal, in the same way it’s not unreasonable to say nylon screws add functionality despite being seemingly legal in the main chunk of R12.

I understand the GDC cannot give a blanket answer with the amount of new weird hardware being made to keep things fair, but the thought expierments they have provided are not sufficieint.


Maybe if the GDC didn’t close the Q&A prior to a major game manual update pinging them for clarification on a confusing rule wouldn’t be necessary.


Right, I think I see what you mean. If they concluded the first paragraph with “, with the following proviso:” then maybe I’d be justified in reading it the way I did.
The keps skirt question might be resolved with a demonstration? The community seems likely to come up with more functions, structures and hacks than the powers that be, and could be charged with demonstrating how each would be done with vex hardware. Allowing non-vex hardware then looks like allowing structures that would be feasible with vex hardware with a lot of work (grinding up nylocks to a lower profile, separating keps skirts) to be put together more easily and provided with spares more efficiently. But it still means judgement calls at inspection for each new potential advantage of a different fastener. Perhaps that can’t be avoided, since we’re here to innovate as well as educate.
To your emphasis of the importance of weight and OP’s question: it seems like a positive move to allow lighter fasteners to reduce the need to specialize every structural member to the extent that that metal is unusable elsewhere. If light fasteners are used on closely-crafted lighter metalwork, then it seems like an unfair advantage could be achieved. That then becomes a region of judgement calls - that I think are covered by a provisoed reading of R12 - or indeed a simplifying decision to ban lighter hardware in a way that can be reliably assessed. So yes, over to the powers that be.



But in all honesty, I do think that the GDC needs to make a definitive statement on the legality of certain parts, like nylon screws. In the past they had said that you could use products that were similar to official VEX stuff, but now that they have simplified/slimmed down the game manual there are some things whose legality have been left in question since the start of the season (and contested by refs, as seen at SD CA states).


Thank you for this <3 but I’m not bothered about my pronouns. At one point I was, but now I have the slightest preference towards they/them and feel pretty equal about he/she. Very different to my feelings a few years back.

And to keep the thread on topic…



My bad… I can’t read.

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