Don’t read into the rules what’s not there.
“Polycarbonate” with no other strings attached is listed as a “permitted material” in rule R92F.
Where (exact rule #) are these imaginary restrictions on what constitutes legal polycarbonate and illegal polycarbonate coming from?
Art, <R92> simply states that “The following items are the only permitted materials for use on the MINIBOTS:”
[list]
It then lists a long line of various COTS-type items and what sure looks like raw materials. While it nowhere says “COTS” or “Fabricated item”, there are strong conclusions that can be drawn from what the terminology says. For example, if the list had said “steel”, would you think that screws, nuts, and bolts were legal? I know I wouldn’t! But screws, nuts, and bolts are called out in another item on the list, so they are legal.
As it stands right now, both sides have the right answer, because clarification has not come. I’d much rather inspections not turn into lawyering to the effect of, “But it’s made of X…” “But it’s not on the list…” Somebody needs to ask Q&A. Something simple, like, “I can buy a COTS item that is entirely made of an allowed material from R92. This item is not listed elsewhere in R92. Is it legal?” would probably work quite well for getting a GDC response one way or the other.
So basically what you’re saying is you’re making up “strong conclusions” based on things you admit aren’t said in the rules at all. Please for the sake of less-informed teams skimming over these threads do not post things you don’t know to be true.
If made of steel, yes.
Reading between the lines are for philosophical or political discussions. FRC rules are black and white.
Now to find some 7068 aluminum bearings
Chris, do you know for sure that it is legal to use items that are COTS on the Minibot just because their material matches a legal material? If so, what rule? I’d be interested in knowing.
Except that this one can be read in two ways, black and white. Like I said, I wouldn’t see that “steel” included “steel screws, nuts, and bolts that I buy at a hardware store”. I’d see “steel” and think, “steel plate, tube, bar that I can form stuff with”. You’re seeing “steel” and thinking “steel, plate, tube, bar, screw, nut, bolt, and other hardware”. Two different points of view, one single word. Because it is quite possible to do that, I propose that we let this topic lie until somebody can ask the Q&A. I can’t do that asking, BTW–no account and no team. Q&A is the only official source for making black or white into black and white.
Since you brought up less-informed teams, wouldn’t we be better off suggesting something isn’t allowed that is rather then the opposite. I’d much rather get to a regional and find out I could use an extra motor then have to figure out how to do without one I was planning on using. Also, I think you should take Eric at his word. He isn’t just a random guy that happens to post on here. He’s read every manual for as long as I can remember and knows people who do the inspections. If he can interpret that way(even if your right and he is falsely interpreting it) so can inspectors.
To anyone that might stumble upon this thread: Don’t use the hinges until it was asked in Q&A.
It’d be the rule that says parts that match what the rules say can be used on the robot. That’s… most of them.
“Polycarbonate” is a polymer. It is not a specific formation of that polymer in any particular sheet - all of which would be “COTS” anyway.
Is the COTS polycarbonate hinge legal?
Ask schrodinger’s cat. Until the Q&A rules on it, the hinge is both legal and illegal.
According to the letter of the rule, as laid out, right now… I believe they are legal. At the very least, they are not specifically illegal.
But what you are seeing here is a number of FRC veterans reading that rule and putting it in to the context of previous GDC rulings over the past several years, and making a reasonable interpretation as to the intent of the rule… and I believe they are correct. I believe the hinge, in the context of the rules and previous GDC decisions, is illegal.
So until someone opens the box, by asking the Q&A or undergoing tech inspection, the hinge, like the cat, is both alive and dead.
Jason
P.S. I don’t want to imply that your robot is “legal” just because you’ve passed tech inspection. It is quite possible that you passed tech due to an oversight by your inspector that will require adjustment at some future point of time.
You could use the tetrix servo-controlled hinges set up with two servos to increase power. You still may need latching mechanisms both to hold the arm(s) in place during robot movement and after minibot deployment.
Many ways to make hinges under the rules from simple things like electrical tape or Velcro to machining hinges from aluminum bar.
For anyone looking to use hinges on their Minibot, this Q&A makes polycarbonate hinges legal:
I still don’t think that’s clear enough. They say there’s no limit on the size, shape, or form of the polycarbonate, but they still don’t say if hinges are illegal or not. Someone needs to specifically ask about hinges.
size shape or form would seem to cover it, so long as all the parts are polycarbonate.
I would use a fastener (screw, bolt) for the hingepin. Better shear characteristics than plastic.