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Unread 20-03-2013, 14:28
stuart2054 stuart2054 is offline
Controls Mentor
AKA: Stuart Sebright
FRC #2054 (TECH Vikes)
Team Role: Mentor
 
Join Date: Apr 2011
Rookie Year: 2010
Location: Hopkins Michigan
Posts: 102
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Re: Full court shooting strategy

Quote:
Originally Posted by thefro526 View Post
It's a hard call to make on the fly, especially in between elimination matches if you want to do it legally.

A wide enough 84" tall robot in the right position is pretty much the end all be all to the FCS game. Even with a high exit point on the FCS (50" or so), the 84" wall would only need to be within 30-36" to render that FCS useless, assuming they're exit angle is somewhere less than 30 degrees from horizontal. (haven't seen something more steep yet)

That being said, there are some interesting trade-offs to this decision.

- Assuming it's something being done very quickly, odds are the 84" tall wall is going to be stuck at 84" tall. If it is, you've now limited your defender to playing on a third of the field... And of that third, you lose quite a bit of it to both the pyramid and your opponents loading zone.

- Assuming you're building blocker that can withstand repeated shots at point black range, it's going to have to be well constructed. Odds are, this is going to shift the CoG of the robot up quite a bit, which could make playing effective defense a bit difficult.

- If the opposing alliance has a capable floor loader, the FCS robot only needs to get discs to the other end of the field, not necessarily score them. In this case, shooting over the blocker becomes a viable option.

Now, if you can make the blocker removable and/or actuate into position, you can ignore a lot of this stuff. But, if you think about it, if your alliance is willing to sacrifice a machine to be an 84" tall wall then odds are, the opposing alliance is willing to sacrifice one of their machines to remove the wall from the equation.

Also, at CH, in multiple matches, the opposing alliance would send two or even all three of their robots after 225's FCS in an attempt to prevent it from getting to the feeder station. One of the things to remember when trying such a strategy, is that you can't win if you're not scoring points... Specifically in Semi 2-1, the Blue Alliance spent the first 45-50 seconds of the match playing defense against 225. During this time, we (341) essentially were playing offense on a completely open field which let us put up some solid points and win the match...
We have a nice deployable tall arm that is about 80 inches high when deployed. It is just a square tube within a tube with a cord that that pulls the inner tube up as the the whole assembly is rotated up by a pneumatic cylinder. It has a bungy inside to pull it back down when the cylinder is retracted again. It does not have much effect on our CG.

We only used it in the last of the Gull Lake district finals after our shooter feeder was damaged and it worked great. The problem is as several have mentioned that it takes you out of offense. We are primarily an offense robot and are loath to use this unless neccesary. I would like to see more defensive robots have someting like this and we have even talked about making something similar to retrofit onto elimination round alliance partners.

You can see this match here http://www.youtube.com/watch?v=S1XVwRkKOlw