leaning against the perimeter wall - Legal?

I watched a video on youtube of a clean sweep robot whose makers had designed one of its appendages to lean against the perimeter wall at the start of the match. By doing this they were able to keep their robot inside the size restrictions of 18’’ by 18’’ by 18’’. After the start of the match their robot would drive away from the wall and the appendage would fall into position. When this happened their robot was larger than the size restrictions. This I know is legal but is it legal to use the perimeter wall to “hold in” your robot’s appendages?

Probably not.

See <R4> Robot must be able to fit in Inspection Box WITHOUT touching the walls. If the robot requires the wall to hold something in place, then it is doubtful that it would pass inspection.

Do you have an example of what you are talking about?

Are you talking about that catapult robot? They did something similar but they may have relieved tension on the catapult at the start, not sure.


There are also robots that have parts that barely stay standing up when they start and as soon as they move the inertia of the part causes it to fall over.

Right but in that case I would say that such a design is allowed.

No part can rest on the field parameter because in the sizing box that part would apply pressure to the box which is not allowed.

The catapults I am familiar with have a little hook on the cocking arm that hold the spatula up, then when the arm starts to **** the spatula drops. It is not supported by the field wall.

LOL at filter…

Rick, I think we’re on the same page I just didn’t get a close look at that particular bot. Thanks, I was wondering about the starting position.

sorry to bump this up but i thought of something. As far as i know there is no rule saying that you need to put your robot in the box drive wheels down. if you had something that popped out of your robot at the beginning of the match when you drive away from the wall (the wall is what holds the mechanism in place) you could size your robot with that mechanism touching the ground of the sizing box and you should be all set.


Only if this is how you set your robot on the field at the beginning of a match. The rule is:

The rule does not say that you just have to be able to fit in a box; it says that it must be a certain size on the field at the beginning of the match. A referee will not allow a robot to use the wall to keep it within the 18", regardless of what happened during inspection.

Just play the game, don’t play games with the rules.

i realize that is is a bit of a stretch but the robot would be within the required volume and be able to be sized.

Another way you could do this it to place your robot with the pop out mechanism on the ground (DT off the ground) then flip yourself back up with your bucket or another mechanism that you already have on your bot by pushing that mechanism against the wall.


I would never use any of these methods (i already fit in the 18" no problem) but as far as i can see they are both legal.

And this strikes me as both completely legal and a potentially clever way to fold out a mechanism at start-up. As long as you start within the 18" cube without using a field structure to hold your mechanism within the box you should be legal.

Since there is at least some chance that the field floor might be considered a structure holding your robot within the 18" cube, it would be wise for a team considering this strategy to check the legality via a question posted on the official Q&A before showing up at an event.

Wicked risky though. You would either look totally awesome doing it or you would look like the moron who though it was a good idea to put his robot on the field on its side if it doesn’t work and you end up never flipping back up.


sorry if this is off topic (maybe i should move this to a new tread?)
but are you allowed to use the preaload BALLS to hold your robot in the 18in?

No, because you cannot preload in the sizing box.

According to rule <R4>, part a, this would appear to not be illegal.

so put your pop out mechanism on the floor on the sizing box, with the DT off the ground, just as you would in a match.