Stabilizer legs

Is it against the rules of the game to make stabilizer legs that come down like a siege tank in Starcraft? they wouldnt touch the bumpers and only come down when placing tubes.

Can you make them fit within the 60" diameter circle?
Can you make sure that they don’t mess up the carpet?

If so, go ahead. Just bear in mind that while you’re putting the legs out and in, every other tube scorer out there will be gaining a few seconds unless you’re pretty quick at pulling them up/putting them down.

It’s allowed to extend beyond the bumper perimeter after the start of the match, while your robot can fit inside an infinitely high 60" diameter cylinder.


BUMPERS must provide complete protection of the entire FRAME PERIMETER of the
ROBOT (i.e. BUMPERS must wrap entirely around the ROBOT). As part of the 100%
coverage, BUMPERS must protect all exterior corners of the FRAME PERIMETER. For
adequate protection, a full segment of BUMPER must be placed on each side of the corner
(see Figure 3-2).

now we must ask, what is the frame perimeter? ::rtm::

FRAME PERIMETER – the polygon defined by the outer-most set of exterior vertices on the HOSTBOT
(without the BUMPERS attached) that are within the BUMPER ZONE.

so what is a HOSTBOT?

HOSTBOT – the electromechanical assembly used to carry the MINIBOT. (ROBOT – MINIBOT =
HOSTBOT). If a TEAM plays a MATCH without a MINIBOT, then the HOSTBOT is the ROBOT.

so what is a ROBOT?

ROBOT – the composite electromechanical assembly designed and built by a FRC team to perfo
specific tasks when competing in the 2011 competition LogoMotion. The ROBOT must includ
the basic systems required to be an active participant in the game – power, communications,
control, mobility, and actuation. The ROBOT implementation must obviously follow a design
approach intended to play the 2011 FRC game (e.g. a box of unassembled parts placed on th
FIELD, or a ROBOT designed to play a different game, would not satisfy this definition). The
ROBOT includes both the HOSTBOT and the MINIBOT (ROBOT = HOSTBOT + MINIBOT).

Based on this alone, it would seem that anything going beyond the frame perimeter at any time and into the bumper zone would be illegal.
That would that tube pick up from the floor would be illegal as well.

I’m sure I’m mistaken about this, but I can’t find the rule that would go around the above restriction… :confused:

Help! :confused:


Thanks, wanted to know just in case

Leav, if it’s illegal to have anything going over the bumpers, then ain’t nobody gonna be able to grab tubes from the floor. Just sayin’.

It’s the 60" diameter cylinder that is the restriction here.

The FRAME PERIMETER cannot be articulated–that’s in the robot rules. The legs would not be part of the frame perimeter during size/weight/starting/transit, as they’re stowed. They are also articulated. As such, they’re legal.

Or someone could just ask Q&A (this isn’t it).

I completely agree, and that’s why my conclusion was that i’m wrong and missing something.

Currently the definition of the FRAMER PERIMETER, BUMPER ZONE and <R07>.A (all quoted above) seem to indicate that anything in the BUMPER ZONE would be part of the FRAMER PERIMETER, which would in turn require compliance with the bumper rules.
That would make building a mechanism to pick up tubes from the floor practically impossible.

I’d love to hear the loophole, otherwise i’ll probably take it to the Q&A.
I’m sure they will allow pick up from the floor somehow but I think the rules will need to be amended.

maybe the FRAMER PERIMETER is measured only at the start of a match? (i.e. the starting configuration)

The FRAME PERIMETER defines the size of the robot, where the bumpers must be attached and which all parts of the robot must start the match within. In other words, the STARTING CONFIGURATION without the height dimension. The PLAYING CONFIGURATION size is defined in the rules (and hopefully Team Update #1) and would allow stabilizers under certain conditions. The least of these involves the type and material used in contact with the floor and the risk involved in deploying said devices. This would open the device to damage and give opponents a greater ability to push your robot. If those risks fit your strategy then it may be worth the effort.
For example…
<R11> During the MATCH, the ROBOT may not exceed the volume constraints of either STARTING or PLAYING CONFIGURATIONS (note: these limits are defined in reference to the ROBOT, not the FIELD).
<R14> When a ROBOT is in its STARTING CONFIGURATION, no part of the ROBOT shall extend outside the vertical projection of the FRAME PERIMETER.


As you pointed out: FRAME PERIMETER is defined in reference to the ROBOT and not the STARTING CONFIGURATION, and PLAYING CONFIGURATION does not add any relevant information here.

Not trying to lawyer the rules around, just wondering: do you agree that the wording needs to changed to allow certain designs such as stabilizers and tube pick up from the floor?

In Team Update #1 the dimensions for PLAYING CONFIGURATION has been changed to 84". I do believe that the stabilizers will fit that rule if other rules are also followed. However, I do not forsee a need for stabilization in this game unless the robot center of gravity is sufficiently high and unstable when outside of the scoring area.

I don’t know who you are but I love you for making a Starcraft reference. I really have nothing to actually add to this discussion because your question has already been answered by other people, I just wanna say that you are awesome. That is all.

This isn’t a question about whether stabilizers (or any other thing) are allowed to go into the 84" area. It’s a question of what exceptions are there to the bumper rules for parts of the robot beyond the (starting) frame perimeter to pass through the bumper zone.

I came across this same problem in a design I was working on which would probably need wheels on the floor outside of the bumper area for stability. As far as I can tell the rules contain no exceptions for anything to pass through the bumper zone without having bumpers appear out of thin air. Even though I’m sure the GDC intended for manipulators to be able to enter the bumper zone, it is very important to know the specific exceptions granted to the bumper rules. We wouldn’t want to have a major component of our robot rejected by inspectors at a competition :eek:

There are specific bumper rules that I was referring to. As an answer to your proposal, from R07…
B. The BUMPERS must be located entirely within the BUMPER ZONE when the ROBOT is standing normally on a flat floor, and must remain there (i.e. the BUMPERS must not be articulated or designed to move outside of the BUMPER ZONE). (emphasis mine)
If I understand your statement, you wish to have robot parts extend through the bumper zone, beyond the FRAME PERIMETER but not beyond the maximum PLAYING CONFIGURATION. The above paragraph would prevent that. A robot part that extends but is outside the BUMPER ZONE, does not appear to violate the above paragraph or any other rule at this point.
I recommend that you ask the question of the Q&A when it opens. The GDC is the only one that can provide you with a definitive answer.


I think you got my idea right. There would be arms that swing out to fill the 84" diameter and then have wheels on the end that reach through the bumper zone to the ground for stability.

Your interpretation demonstrates the problem though. If my device is forbidden, then any arm that has a claw which goes through the bumper zone to pick up a tube is also forbidden, which I really hope the GDC is not doing. I Do intend to take this to Q&A tomorrow though.

(PS It’s funny the kind of ideas that pop into your head while trying to explain to your mentors why it would be illegal to have bumpers that reshape themselves during a match)

<R06> limits what kinds of materials can touch the floor.
Be sure to avoid <R05>
Overall I think it’s possible to deploy outriggers for stability, but I think that designing for a lower center of gravity is a better idea.

The Blue Box in <G48> indicates that you can put things outside your BUMPERS during game play:

ROBOTS place mechanisms outside of the BUMPER PERIMETER at their own risk; no penalties will be assigned for incidental contact with such extended mechanisms.

However, this is the first year in which we had 100% BUMPER coverage and are able to expand outside the FRAME PERIMETER. To avoid inconsistencies, the definition of FRAME PERIMETER should be changed to indicate that it is measured in the STARTING CONFIGURATION only.

I agree with this conclusion. let’s hope the GDC is on the same page… :slight_smile:

I know this is confusing but the FRAME PERIMETER doesn’t change, even with PLAYING CONFIGURATION. The FP sets the robot size for sizing, and therefore the STARTING CONFIGURATION. It also sets the inside perimeter of the robot where the bumpers are mounted.

Al, I know that’s what it is, but I don’t know anywhere that says that.

Not much room to work with, but the bumper zone is one inch above the floor. I already sketched out a mechanism with tiny wheels that would extend under the BZ in the direction of a deploying arm as a stabilizer. As the arm comes back into the FP upward projection the stabilizer retracts also. Nice to think about, but it’s looking too complex for 5.5 weeks, durn it. If you want my drawings LMK.

Gary, I am working from these definitions in Section 01,
FRAME PERIMETER – the polygon defined by the outer-most set of exterior vertices on the HOSTBOT (without the BUMPERS attached) that are within the BUMPER ZONE.
To determine the FRAME PERIMETER, wrap a piece of string around the HOSTBOT at the level of the BUMPER ZONE - the string describes this polygon.
Note: to permit a simplified definition of the FRAME PERIMETER and encourage a tight, robust connection between the BUMPERS and the FRAME PERIMETER, minor protrusions such as bolt heads, fastener ends, rivets, etc are excluded from the determination of the FRAME PERIMETER.

PLAYING CONFIGURATION – one of any of an infinite number of postures a ROBOT may take once the MATCH has begun.

STARTING CONFIGURATION – the physical configuration and orientation of the ROBOT when the MATCH is started. This is the state of the ROBOT immediately before being enabled by the Field Management System, before the ROBOT takes any actions, deploys any mechanisms, or moves away from the starting location. This configuration is static, and does not change during a single MATCH (although it may change from MATCH to MATCH).

And these rules in Section 4,
<R11> During the MATCH, the ROBOT may not exceed the volume constraints of either STARTING or PLAYING CONFIGURATIONS (note: these limits are defined in reference to the ROBOT, not the FIELD).
Maximum Horizontal Dimensions 28” x 38” (71.12cm x 96.52cm) rectangular space
Maximum Height 60” (152.40cm)

<R12> The FRAME PERIMETER must be comprised of fixed, non-articulated structural elements of the ROBOT.

<R14> When a ROBOT is in its STARTING CONFIGURATION, no part of the ROBOT shall extend outside the vertical projection of the FRAME PERIMETER.

As I said, confusing…