http://forums.usfirst.org/showthread.php?t=13940
Can somebody help me to understand this Q&A response? The question is certainly a little unclear, but the way I read it, I’d be inclined to believe it’s legal. Since the GDC opted to be curt in their reply, and didn’t explain what rule the asker’s design would violate, I don’t know how they read the question, and consequently I don’t know what they’re ruling as illegal. Any guesses?
You aren’t the first one. I believe the key words are “expand and retract, within frame configuration, [to fit] through the tunnel”. This indicates an articulated or expanding frame of some form, which is illegal under <R11>.
The question was also poorly worded, so I’m not surprised that it got such a short answer. I would also not be surprised to have clarification requested within a day or so on Q&A.
I think that the question was supposed to be asked, can the robot expand and contract within the set limits, without moving the bumpers out of the bumper zone.
I would think that this would be illegal because that would change your bumper perimeter.(violation of <R7>)
It wouldn’t necessarily change the bumper zone (assuming the bumpers never moved).
In any case, the question was poorly worded, so I think the GDC decided to just invite requests for clarification.
If we assume the direction of “expand” - “retract” - “expand” remained exclusively in a vertical direction, without the 60" height limit ever being exceeded, then I think this would be legal. The “NO” answer seems related to any horizontal expansion, where I am also confused.
Can a robot have an initially small size NON-articulated frame scheme with bumpers mounted and then have something swing out horizontally above & beyond the top of the bumper, but NOT extending beyond the 28" x 38" horizontal limits? I think the answer is: NO, because the bumpers could no longer offer protection for this member protruding beyond them above 16", and it would also pose a danger to other robots by jabbing into their upper structures above their bumpers.
The vertical expansion should be be allowed. What if I want to drive through tunnels earlier in the match and then grow the bot vertically to 60" at some point prior to the end of match, so that it is closer to the tower bar when the full expansion period finally starts. It can save me some time by already being at the 60" point, compared to reaching the bar from the smaller tunnel compatible size.
-RRLedford
If vertical expansion is not allowed, then I would expect the next Update to announce this.
Also, RRLedford, you forgot the restrictions placed by rule <G30>, which limits anything from leaving the frame perimeter with some few exceptions. I would presume that the scenarios mentioned are precisely the reason for this rule.
There is so far no clarification.
Next year there will be a decal or sticker to be placed on the robot. it will form the origin point for a coordinate system of your choice. Robot dimensional limitations can then be expressed as distance from the origin point. But be careful, the limits may include rotational inertia in each of three dimensions about that point in addition to the usual weight limit. 
:rolleyes:
IMHO the “NO” answer is without basis and contradicts team update 2 <G45>. Above the bumper zone…“Resetting or moving mechanisms while not in contact with a ball is permitted”.
We understood the volume rules and team update 2 as we could collapse or expand vertically as long as we weren’t contacting a ball.