12in Perimeter Extension

I was just wanting to confirm something and making sure I didn’t miss anything. You can only extend 12 inches from the frame perimeter in any direction at all times. Specifically endgame doesn’t get more length, correct?


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Though your height is unlimited, I think, as long as the perimeter is within twelve inches.

Did I interpret this correctly, or am I missing anything?

You’re frame perimeter is infidently tall. You can only extend height during the endgame.

There is a hard cap for hight at 45” with the exception that you can extend above that for the explicit propose of grabbing the rung to climb



This may be pertinent

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Thank you! I couldn’t find the exception to the rule earlier

so when hanging, if your robot tilts to, say 60 degree, then it violates this rule?

“as measured when it’s resting normally on a flat floor”

No it does not violate the rule

well, the diagrams suggest otherwise tho

What about extending underneath? Like dropping a bar down for an alliance partner to climb on? Height would be a constraint, but it’s not impossible. Two short robot could Ake it work. Also guaranteed ranking point if climbing in middle, so it would be level.

Im guessing this would result with a similar ruling like 2018 (and other years I think), where it potentially affects your bumper zone since that is measured sitting on a flat floor. So technically speaking, having jacks under your robot, would move your bumpers higher.


Which diagrams? The blue box on G18, specifically example C, shows that if the ROBOT was moved to a flat floor, then the extension is too long, so it’s marked as a violation. But example B, the tilting ROBOT, is OK.

The reference plane is always the “bottom” of the ROBOT in standard configuration. This would typically be the bottom of the drive wheels. It has to stay compliant with G18. If your ROBOT rotates as it HANGs you likely are going to violate this rule.

That’s a good point, I know of a couple teams got dinged for that last year as well. Hopefully FIRST can clarify this at some point in the future. I think most teams can agree that FIRST wants collaboration in achieving rankings points, so they intentionally made it difficult for buddy lifts and for one team to get to stage 3 alone.


If the extension blocks a goal, blocks an opponent's shot, or scores a goal, additional Tech Foul per instance.

Would this mean that you can block shots as long as you don’t extend over 45 inches? Or am i interpreting it wrong.

Sure, why wouldn’t you be able to block shots if you’re not exceeding the height limit? When you’re designing your shooter, you should consider whether it can shoot over a defender at max height against your bumper.

The quoted text (from G17) just adds an additional tech foul per instance if an illegal extension past 45" scores you points or interacts this the opposing ALLIANCE. IE you get dinged with the 15 point foul for extending past 45", and an additional 15 points per instance of the listed cases.

Getting a climbing extension the you deployed early stuck up may be very expensive. Point to consider when designing vertical extension mechanisms.

Blocking shots as long as you are in a legal configuration is perfectly legal.

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