6.270 2001 Rules Committee Rulings

The following are questions and responses from the 6.270 Rules Committee. Please send all rules committee questions to 6.270-rules@mit.edu.
1/28: Starting sequence

Q: What is the exact starting sequence?
A: Here is the final, updated starting sequence:

  1. You will know which table and which side of the table you're on, and you'll proceed to the check-in area while the previous round is running at your table. Note that from now on, your beacon may not come on until the round begins, or you will be charged with a false start. Two false starts result in a disqualification from the round.
  2. Your robot's size will be measured, and your team number and name will be taken to the table announcer.
  3. Your table escort will lead you to your table, and you can begin setting up your robot. At this time, you can calibrate your sensors and actuators, and your sensors and actuators are allowed to run. The starting light will be on. You should also take this time to run through a final checklist of verifications.. such as Hawkers being on, etc. You'll have 60 seconds from the time the 2nd teams gets to the table to set up your robot. If you take too long, you'll be charged with a false start.
  4. Say "ready for orientation" when you are done with the rest of your set up. When both teams are ready, we will tell you your orientation, and you must place your robot in that orientation. You may not do any form of calibration at this time. Your actuators must be powered down by this time. This means that servos must be disabled and powered down by this time. If your actuators come on, you will be charged with a false start. The starting light will still be on at this time so you can use its readings to center your robot if you wish. (You just can't give your robot any more information.)
  5. Say "ready for off" when you're done placing your robot. When both teams are ready, the starting light will be turned off, and the table master will say, "lights are off". You are then to hit a button to arm your robot. Be sure to do this step! Your robot should now be ready to go once the starting light comes back on.
  6. Say "ready for go" and step away from the table when your robot is armed. When both teams are ready, the table master will begin the round, and your robots will hopefully begin dueling!
1/21: Number of motors

Q: Can I plug 2 motors into the same port? Can I use more 6 motors on my robot?
A: No. You are limited to using 6 motors, 1 for each motor port. The reason for this is that the motors, when stalled, already draw enough current to max out the capacity of the motor driver chips. Since stalling is not always avoidable and we do not want people to risk burning out their chips, we do not allow for more than 1 motor per port.

1/18: Modifying parts

Q: What sensors/actuators may I modify?
A: You may modify sensors and lights freely, but you may not modify actuators (servos and motors) except for mounting purposes.

Q: May I take the NiCd batteries out of my handyboard and mount them somewhere else, on a longer wire?
A: Yes.

1/11: Decorating your robot

Q: Can I paint my robot to fool others into thinking that it's a wall?
A: No. Decorations may not serve any useful function.

1/11: Robot size

Q: How is the 12'' x 12'' x 12'' robot size limit measured?
A: Your robot will be placed on a flat surface, bottom side down. We will try to lower a 12-inch box without a bottom or top (so the beacon can fit through) over the robot. Your robot must fit without any switches depressed, though wires may be pressed in.

1/11: Wires

Q: Can I drill holes in lego for wires?
A: Yes, as long as they don't serve a structural function. We are in favor of cleaner wiring.

1/11: Moving your IR beacon

Q: Can I spin my IR beacon during the contest?
A: Yes.

Q: It's hard to spin the beacon while keeping it fixed with respect to the controller board. Can I move it a little?
A: We'll consider it "fixed" if it stays within a circle of diameter 4'' that is entirely contained in the 12'' square into which your robot must initially fit.

1/10: Starting Orientations

Q: How will the initial orientations compare for the two robots?
A: The initial orientations for the two robots will be radially symmetrical. That is, the 4 possibilities are:

  1. Away (from other robot/from center of table)
  2. Toward (other robot/center of table)
  3. Left (i.e. facing your half of the table)
  4. Right (i.e. facing your opponent's half of the table)

1/10: Setup period clarifications

Q: What happens during the 60-second setup period before the round begins?
A: All you really need to do is to put your robot down in the proper orientation, and, after the starting lights are turned off, hit a button to put your robot in a "ready" state where it will activate once the starting lights come back on.
Optionally, you may choose to calibrate your sensors or motors during this time, though you shouldn't need to.
At no point after impounding are you allowed to give your robot any information other than explicitly allowed calibrations. Specifically, you may not tell your robot its orientation or the side of the table that it's on. It must determine that for itself.

1/10: Throwing balls above 16''

Q: Can a ball be thrown over 16 inches high?
A: Yes, but you must release it before it gets to that height.

1/9: Harming your opponent

Q: May I ram my opponent into oblivion?
A: Yes, as long as your point of impact is blunt.

Q: Are ramps considered blunt?
A: Yes. You can try to flip your opponent or lure it off the table.

1/11: Robots breaking apart

Q: Can I swap in replacement modules if the ones on my robot break?
A: Yes, any kind of rebuilding with identical components is allowed, but you should not be planning for your robots to break!

Q: Can I remove hopelessly damaged modules from my robot between rounds?
A: Yes.

Q: Can I tell my robot which damaged parts have been removed?
A: No.

Q: What if the falling ball always smashes my deflector?
A: If your robot breaks most of the time, it may be disqualified. Since broken robots usually don't win, we expect that we won't have to enforce this rule.

Q: What if my robot breaks when it encounters another robot.
A: We do not allow parts that intentionally break off. For example, you may not use loosely attached legos that will fall off into your opponent's gear train.

1/9: Robots with many nearly separate parts

Q: Can I weave wire into a LEGO chain connecting different parts of the robot?
A: Yes, but the key phrase there is "weave into". You may not strap the chain onto a huge cable, since wires may not be used for structural purposes.

1/9: Using the dowel

Q: What can I use the dowel for?
A: You may use it only for mounting the beacon. However, you may mount sensors on the section that supports the beacon.

Q: Can the dowel go higher than the beacon?
A: No. Nothing may be extended past the plane of the beacon PC board, since it may obstruct the IR transmitters.

1/9: Ball dropping

Q: Can I use my beacon to deflect the falling ball?
A: Yes...but remember that if your beacon breaks, you will be disqualified.

Q: Can you clarify the timing of ball drops?
A: If the central ball is disturbed within the first 17 seconds, a ball will fall onto the platform at 20 seconds and 40 seconds. If the central ball is first disturbed between 17 seconds and 37 seconds, a ball will fall at 40 seconds. Otherwise, no ball will fall.

Q: Can I fool the sensor measuring the central ball?
A: Probably not, but even if you do, an organizer will notice and drop the balls manually according to the rules.

Q: Which extra ball will drop first?
A: It will be random.

Q: From what height will the ball drop?
A: The bottom of the net that slows its fall will be about 22'' above the central platform.

1/16: The $20 rule

Q: Can I buy weights? Can I buy springs? Can I buy solenoids? etc...
A: No. You may only buy electronic components, but any kind of actuators, motor driver circuitry, or microprocessors are explicitly disallowed. Two exceptions: you may buy FETs to power LEDs (we have a bunch) or servos (we have some that are heavily discounted).

Q: If I replace broken servos with servos I buy elsewhere, will those count toward the $20?
A: No. As long as you replace them with the exact same model, you can pretend that you never broke them in the first place. However, we will not sell you more than two.

1/9: Extra batteries as weight

Q: Can I use my extra battery pack as a weight?
A: Okay.

1/17: Strings and rubber bands

Q: Can we use strings or rubber bands to transfer force to moving parts (for example, to make pulley systems connected to a gear train or dropping weights)?
A: Yes, as long as the string is not a structural component and all parts are still connected by LEGO.

Q: Can we use rubber bands to store energy?
A: Yes. You can even wind them up before the round, and have them release at 59 seconds, so that your robot continues moving for a while past the end of the round.

Q: Can we use rubber bands to add friction to our wheels/treads/legos?
A: Yes, as long as they do not provide structural support.

Q: Can we use huge-ass rubber bands?
A: No, but you can use as many small ones (less than 1/8'') as you want.

Q: Can we make a net/conveyor belt/ball grabber out of strings or rubber bands?
A: No. That would make it a structural component.

1/9: Qualifying

The requirements for qualification are somewhat subjective. Even if your robot has a bad run, if it looks to us like your robot is capable of scoring points, you might qualify.

1/9: Double wins / double losses

Q: In the situation where both teams have defensive strategies resulting in a tie, but one team has an unsuccessful offensive attempt, how would this be scored?
A: Both teams will lose. To win a tied match you must actually do something that increases your relative score at some point in the contest.

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