View Single Post
  #19   Spotlight this post!  
Unread 15-03-2010, 17:24
RRLedford RRLedford is offline
FTC 3507 Robo Theosis -- FRC 3135
AKA: Dick Ledford
FRC #3135 (Robotic Colonels)
Team Role: Mentor
 
Join Date: Jan 2010
Rookie Year: 2009
Location: Chicago, IL USA
Posts: 286
RRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond repute
Re: Team 39 building 469 stopper solution (Available in Las Vegas)

Team 3135 came close to choosing a loop bot design at the brainstorming stage. We finally bailed on it because it seemed too risky with respect to the rules.
We had already completed a similar concept in FTC Chicago that caught 15 balls right out of the drop chute, and even caught the yellow ball later. Our shooter was just too weak and erratic though, so we only took second place.

With FRC, we could not clearly interpret whether a gravity powered ball re-director chute could be rotated for targeting to either goal (as 469's flipper does), without violating the rules. So, 496's stationary 2-way chute with a flipper to steer balls to either side works well - smart! Our team also felt that, beside risky, it was also in conflict with the "spirit" of the game, and so the idea got voted down.

Hats off to #469 for taking the risk and confirming the legality of this scheme - we were too timid to gamble. Meanwhile, the neutralizing concepts must be worked out. We did consider these thoroughly while we still entertained doing the looper scheme.
We had assumed that the bot's re-directing chute would have to remain stationary while "shedding" a ball toward one goal or other. We assumed balls would be "INSIDE OUR PERIMETER" by more than 3" at this stage, so any moving mechanism touching the ball would give a penalty. After "shedding" a ball from our static chute toward one goal, I had assumed the rules allowed us to then re-point our chute, just before next ball arrived, toward whichever goal seemed least defendable. Since 469 never turns their ball chute once it's positioned on the platform, they avoid the penalty of manipulating balls that are inside their perimeter. However, they do operate a flipper to route balls through either side of chute, as balls come down the 2-way chute. A moving mechanism while ball is above bot's base should be a penalty, since ball IS WITHIN THE BOT's (virtual) PERIMETER, which projects vertically up from base. Do they move the left-right flipper before ball drops onto bot, or after it starts sliding down the chute? Not clear from video?
Now as to defending this:
1) Can a fast defender bot sit centered in their zone and intercept balls based on anticipating which way 469 points their ball flipper? I think so, but I can't tell how long into their cycle they wait to commit as to which goal they are targeting? It seems to be VERY last second commit for diverting balls left or right on the chute. Plus, the defender must not only intercept balls, but also clear balls from their zone while two opponents are harassing them - not so easy!

2) can a hump navigator bot go up on (or adjacent to) the climber platform , latch on to a pipe, and obstruct the flow of the balls coming through 469's ball chute, or even poke it out of the air before it arrives on their their chute? Risky, as contacting 469 in any way could be a penalty. Perhaps a "wall bot" that's wide enough to block their trajectory toward either side? Not so easy though, as they (wisely) chose to drop balls onto the hump to gain better horizontal shot velocity, which also gives them a harder-to-block, wider angle of chute discharge. ***WOOPS, NO EXPANSION AT OPPONENTS TOWER NIXES THIS!! FORGOT.
3) My favorite idea at this stage it to "poke a stick" through their chute at the appropriate spot to stop ball flow through it. Perhaps even poke a stick right at spot where balls leave the return ramp. Can this be done so as to choke up all the returning balls in a queue on top of their ramp? Is it legal, as long as no contact with ramp is made? The max expanded height seems to allow this.***WOOPS, NO EXPANSION AT OPPONENTS TOWER NIXES THIS!! FORGOT. If so, it would be poetic justice for them!
-Dick Ledford - #3135 mentor

Last edited by RRLedford : 15-03-2010 at 19:10.