My team is looking at various aspects of hanging, and I recall many FRC teams doing a hang using momentum (example). I was searching youtube and found one with an FTC bot doing it unsuccessfully. Has anyone else tried doing it, and if so, how did you get it to work? We are thinking that our little robot won’t have enough momentum to do what the bigger FRC bot did.
This is how we hang. It works really well. It enables our robot to get on the bar in mere seconds. The hard part is getting the right size for the wedges and the positioning on the robot.
I’m CAD’ing some stuff up now to prototype tomorrow, but I’ve heard teams have had issues with building up enough speed (on the bridge thing) to be able to make it work. I was thinking about grabbing it (see attachment_test) and using some strong “rubber bands” to pull it down (see attachment_test2). What have you figured out that works best?
To be the winning alliance, when the strength of competition is high, almost demands that an alliance be able to do a double hang. We designed our robot to consistently wind the flag in ~5 seconds, and be able to get in position on the bridge fast enough to complete a double hang with partners already hanging. Our mechanum drive trail allowed for precise lateral positioning, so that we could avoid going across the bridge centerline while doing the double hang.
In our 2nd regional competition this past Sat., we made it to the semifinals with the 4th seed alliance. We had not yet executed a double hang, but our alliance captain was an small pyramid shape robot, a perfect match for our dual hook arm, double cord winch design to do a double hang. We completed the flag wind super fast and made it onto the bridge at optimum location with enough time to complete the double hang, but out partners did not want to risk us knocking them off the bar, so we just sat there watching the time run out.
We could have won 1st match with the double hang, as we were out matched on blocks and behind in the scoring, but letting that one chance slip away led to us being eliminated in the next match, where we tried to double hang with the 3rd partner but arrived too late on the bridge.
-Dick Ledford
Team FixIt (3491) uses a similar design as the one in the video, but theirs works every time.
I’d like to see a vid of a passive FTC hanger, I thought I would see more of them but haven’t seen one yet.