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I'm worried about the <RG08> rule and it's limits to shooting only 16 feet.

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  • I'm worried about the <RG08> rule and it's limits to shooting only 16 feet.

    I'm writing this because our team's experience is that it is very easy to shoot the rings farther than 16 when designing the shooter. If you bother to pay attention to this rule it makes it impossible to shoot from farther than 9 feet away and not control both the angle of the shooter and the velocity that the ring leaves the robot. The very first video shown at kickoff by Gluten Free clearly violated the shooting distance rule. Many videos I'm now seeing of good scores are also showing velocities and trajectories that would violate the distance rule. My team is struggling with limiting our robots capabilities during the remote competitions, while watching other teams not bother to do so. We've even asked around, and found that some teams think it is a poor rule and are ignoring it, thinking it will be changed by the time conventional competitions resume. I'd like to hear from other mentors what they think, and should we push for a change to this rule. Even opening the flight distance from 16 feet to 20 feet would make this a much more reasonable rule. I estimate the velocity would go from about 23 feet/sec to 27 or 28 ft/sec. I'm including a picture of different trajectories required to stay within the 16 foot distance rule, and have the ring reach the upper goal. The trajectories get pretty ridiculous when the robot is farther away from the goal. If we wait till later in the season to deal with this I'm afraid many robots will find themselves failing inspections at competitions and have almost no chance of changing the operation of their shooter in time to actually compete.

  • #2
    I agree FIRST needs to address this topic. In various posts or discussions I have read or heard contradictory statements from "we are going to ignore it since we can't test it", to teams not being able to get through inspection because it is tested at inspection and they fail. Any shot that is launch at 8 ft or further and has not reached it's peak will result in breaking this rule. Many of the on-line videos are breaking this rule.


    • #3
      Thanks for your response. I was hoping that more people would realize this is a real problem. I keep seeing more and more WR videos that are breaking this rule. You are correct about the 8 ft.. From what I can tell, all a judge would have to do is observe if the ring still going up when it entered the goal and that would be enough to call the team in violation. So for others reading this please respond with your opinions. If I can get a feel that many teams would back changing this rule, I'll try to find a way to approach the game design committee.


      • #4
        At this point in the season, I don't think it would be fair for <RG08> to be changed. I also think it's important that teams participating in Remote Events responsibly & honestly comply with <RG08> as well as the other rules, just as they would at a Traditional Event. It's the responsibility of the Coaches/Mentors to make sure this happens. IMO, <RG08> creates opportunities for teams to differentiate their design from those of other teams, particularly for the judged awards.


        • #5
          I have the same concern.


          • #6
            It is a rule and design constraint. Design your robot/shooter accordingly. And it is possible to shoot and score from beyond 8ft - if you use the downward side of the arc. Deal with the design.
            OP is correct that many videos show teams that are clearly violating the rule.


            • #7
              Maybe I'm missing something, most of the videos I have seen, bots are at the 6-7 ft area, pretty close to the line - and it is still going upwards.

              This seems perfectly fine, it is just the first graph shifted to teh right, and frankly I'm not sure why a team would choose to shoot from 8+ feet away, and deal with the increased inaccuracy that comes with the plateau and falling portion of the arc. In other words you can have an arc that is right at say 15 foot, and drive right up to 5.5 feet away from the goal, and be dead on accurate every time. Why not do that?

              IMO, the concerns raised are an issue ONLY because of the Covid situation and remote vents. In a normal year I'd think that inspectors would be watching closely and people would be taking this seriously. The really good teams would know that while maybe they could get away with it at a local regional comp, once they hit states they'd be busted for sure.

              I actually think its a great rule b/c it forces the kids to do some thinking and plan apprpriately. I know or kids' initial plan was "OK we'll shoot right from teh starting position in auto b/c thatst he most accurate spot", but the math told them "Not so easy, my friends..."
              Last edited by RatLabGuy; 01-25-2021, 12:13 AM.


              • #8
                The trajectory analysis of a ring if far more complicated that the assumptions used in #1 (however it is a good start). You have to consider the aerodynamics factors as well as the potential for the ring to be rotating about all 3 of its axes (x,y,z) while in flight. The peak of flight may not be at half distance. Consider a frisbee, which if thrown in a certain way can achieve maximum height and distance at the same point. A ring is not the same but hopefully you get the idea. The best thing you can do is test your launch mechanism (a few times) with an initial trajectory angle and velocity that is representative of actual operating conditions. You might be surprised at the result.