Mini-bot Hinges

[Chris is me]

Originally Posted by EricH

If I were to go out and buy VEX metal (aluminum), I might have a hard time passing inspection as the rules stand. But I can go out and buy aluminum and machine it into VEX metal, and I'd get some funny looks but would probably pass inspection.

To put it frankly - I think you're making that restriction up. It's said nowhere in any Manual, you're just deriving it.

And for what it's worth (standard disclaimer that even posts by Dave Lavery on CD are no substitute for the Q&A here):

Originally Posted by dlavery

Isn't [Vex metal] still [aluminium sheet]?

If the Manual was worded differently I don't see why he'd make that post...

[artdutra04]

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?

[EricH]

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.

[Bob Steele]

Originally Posted by Chris is me

What I was trying to say is that Team Update 3 does not require that teams are the group that fabricated said materials - if the items are made from things exclusively from that list they are legal.

I think you are swimming in dangerous water if you think that when they say polycarbonate that means you can use anything made of that...
i believe that the rule says polycarbonate and not polycarbonate parts...

This is one to ask Q and A

I will be very surprised if they say that a pre-made polycarbonate hinge is the same as "polycarbonate"

As an inspector unless I had a definite Q and A response that indicated that this was ok I would not allow that pre-made hinge.

And by the way... VEX metal isn't made of aluminum it is made of steel.
(You can get a very expensive set of VEX parts made in aluminum but the pieces you get in the kit and that 99% of all teams use are made of steel.

Dave's statement can be interpreted several ways... you decide how to do it..
Yes VEX metal is still steel...it was made of it...

But is steel the same as vex metal..???

[wexlerd1]

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.

[IndySam]

Many ways to make hinges under the rules from simple things like electrical tape or Velcro to machining hinges from aluminum bar.

[artdutra04]

For anyone looking to use hinges on their Minibot, this Q&A makes polycarbonate hinges legal:

http://forums.usfirst.org/showthread.php?t=16317

Originally Posted by GDC

There are no restrictions on the size, shape or form of polycarbonate used in the construction of the MINIBOT. FTC rules do not apply to the FRC game.

[nitneylion452]

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.

[BJT]

size shape or form would seem to cover it, so long as all the parts are polycarbonate.

[Jimmy the Kidd]

Originally Posted by BJT

Update#3 seems to rule out hinges on the minibot. you could make one, but purchasing a pre-made hinge, regardless of material, seems to be out. right?

A couple of the posters here and I seem to have the same opinion. You should be able to only MAKE hinges. Buying them is against the rules.

[awesomeguy1235]

well, if it is listed in the parts you are allowed to use, then you can, but if it is not, then just forget it, my team thought of arms that used pulleys and surgical tubing to clamp it shut

[PAR_WIG1350]

Update #3 still doesn't rule out the polycarbonate hinge. I'd Q&A that one if I were you.