Unofficial response to "Clarification of previous ruling of <G2>"

Mr_L_on_Yoshi You asked the following:
“A few weeks ago, I asked this question. After presenting one of our sister teams with this ruling, they sketched up a design and asked me to model it. I am not finished, but the attached images should be able to show the point I’m trying to make. One image has the 18 inch by 18 inch bounding box around the bot to show it is inside of that area. Would a bot in this configuration be legal, taking into account that the wheels are contacting the able at time of measurement?”

Given the way robots are measured, the only way this bot is likely to be legal is if it can start by standing on it edge so that the horizontal plane of the robot is less than 18". You might be able to pull that off. If so, that would be really cool. If it will not stand by itself such that a sizing tool can go around it on a horizontal plane, I am confident Karthik will say no.

<R4> At the beginning of any match, robots must be smaller than 18” x 18” x 18”.
a. During inspections, robots will be measured in one of two ways

i. Robots will be placed into a “sizing box” which has interior dimensions matching the above size constraints. To pass inspection, a robot must fit within the box without touching the box walls or ceiling.

ii. Robots will be sized using a VEX Robotics Competition Robot Sizing Tool. Robots will be placed on a flat surface and must not touch the measurement slide as it is passed over the surface.

Please see for a visual reference.

I think this answers the question.

@blatwell It indeed does, in a technical sense. @Karthik gave a previous ruling that states

This ruling indirectly implies 2 things: teams have a choice between the “sizing box” and the sizing tool, and the “sizing box” defines up as the vector opposite in direction to the force of gravity.
The first point of these to consider is the choice. The sizing tool, when properly used, measures 18" from the table, no more. However, Karthik’s ruling directly said the cube can in fact stand on its corner without support. If a bot theoretically could do this, the top of the bot would be above 18" from the surface of the inspection table. This is in direct violation of <G4> ii. The only scenario where both Karthik’s ruling remains true and <G4> ii can be violated is that a team has a choice between which sizing method they use. So, a team in this situation would choose <G4> i. If this choice is not allowed, Karthik’s ruling would be violated.
Secondly, the statement that this particular example should be legal. <G4> i states the following:

According to geometric rules that I hope everyone accepts, the terms “walls” and “ceiling” are relative terms. Because a bot, that would be considered legal according to the direct 18" cube, could either not physically touch the bottom of the box because the table is in the way or can touch the bottom of the box legally. In both of these scenarios, we must decide what classifies as a “wall,” the “floor” and the “ceiling.” It is generally excepted that a ceiling is up, walls are out, and floors are down; following this common knowledge we can say the two faces perpendicular to the table in this example are the walls, the two sloped faces that can be viewed by looking down on this box are the ceiling, and the remaining two faces are the floor. Because we deduced that the floor is either touched legally or can be below the robot, permeating through the table, (both of these scenarios give the same outcome) we are brought to one situation where the bot is legal:
Touching the floor of the box is legal: This implies the bot can be supported by the cube. Karthik’s use of the word “else” states that the bot must either be supported by itself or the cube. Karthik never mentioned the table in his ruling, (I just now realized I’m assuming Karthik to be male. Is this true?) forcing the bot to be technically unsupported by the table. Because cubes, and to an extent, boxes, are closed 3D objects, have edges, we can say there is some discernible gap between the table and the very bottom of the bot due to the thickness of the faces. (in this scenario the robot is the maximum 18" by 18" by 18" size. I’ll explain what happens if its smaller shortly ) So, the robot must be supported by the box per Karthik’s ruling, assuming toughing the floor is legal. Of course, the box/cube must be supported too. This means if a bot is completely above the table, and the cube must be as well, it would fall over, rendering this application useless. Although, this “sizing box” is still in quotations, implying that the box itself can be practically anything. If we do not assume that this material can pass through the inspection table, we can see that a robot which is not (18 x sqrt(2))" tall but is more than 18" wide can be legal. The cube would be supporting the robot; the table supporting the cube due to the properties of the material. This would place the robot a very small distance off of the inspection table. This, in turn, would satisfy all the rulings needed and render the bot in the original post legal.
Or if you want to think of it like the cube is permeating through the table and the bot is resting on the table, that may be easier. (although not technically legal per Karthik’s ruling)

I know I got far more technical than needed, but I feel it important to point out the error in thought here. (mainly that a bot MUST fit under the sizing tool) [Also, I was bored and this was an amazing use of my time] And hey, there’s only one way to find out for sure if this is legal: wait for Karthik to reply to the original post. I hope he logically thinks out this problem and deduces what I have. Besides, a robot in this setup would be at a slight size disadvantage; some of the cube would be cut off. There would at least be a trade off in taking this route. Also, if flipped on its side, this bot could be measured with the sizing tool; one would find it to be in specs at that orientation. Then, using this logic, the bot could start the match with the wheels on the foam tiles.

I’m going to do the best thing ever and respond to the most important thing in your post. (Joking. I just don’t have a response to the rest of it because I’m not sure about it.)

Yes, @Karthik is a dude. And yes, his last name really is Kanagasabapathy. Say that ten times fast. :slight_smile:

Never knew that! Thanks.

Yeah, they say that whenever they announce him at Worlds: “Kaaarthik KAAnagAAAsAAbapathy!”

In your other post it says that the orientation of the robot must be the same orientation that you will start off on the field.
“The Robot must be placed in the Cube in the same Orientation that it starts the match. Thus if your Robot needs the Cube to stand on its corner, the Robot would have to start the Match standing on it’s Corner and not be supported by anything else.”

@1815 Delta II That is true. Is there a contradiction I haven’t looked over? I know I wasn’t entirely clear in my ramblings.

I am not a betting man and I do not eat donuts, but I would bet dollars to donuts that Karthik will say that the only way this is legal is if the robot can stand on its edge unassisted and have the ability for the sizing tool to go over and around it and it would also have to start that way in the matches (some wheels up).

As event partner, we only use the sizing tool, not a box. So, were you to bring this hypothetical robot to inspection, you would need to stand it on its edge in the same way you would have to at the start of the match. The sizing tool would then run over the robot. If the robot catches onto it, then it fails inspection. This includes screw heads, license plates, decorations… The robot will need to remain balanced in its configuration through the inspection sizing process.

You guys should be able to easily solve this issue by having pneumatic legs that stand the robot on its edge, which holds the robots’ position before the match starts, then the pneumatics will contract, making the robots’ cube be on a 45 degree angle when the match does start.
But to be honest, I think this will be an issue that wasn’t solved in the manual. And since it doesn’t say you can’t have that 18" cube at any orientation, it should be legal for now. But it’s up to Karthik to say if it is truly legal or not.

Ah well, he said it isn’t. It was a nice try though :wink:

Yea :D, that would’ve been awesome, though!

As long as you can get it to start in the correct position so that it measures via the way the rules state, you can do it. Pneumatic piston is one idea. Another is a kickstand with a rubber band that will pull it in and secure it once the robot falls wheels down. You could have something from the turning of the wheels that cause the release of the kickstand.

This is totally doable.

Now, how to power it before the match. Rubber & motors with a differential?