Thread: Goalie Bots
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Unread 04-03-2014, 16:28
ohrly?'s Avatar
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Re: Goalie Bots

Quote:
Originally Posted by AllenGregoryIV View Post
As long as a robot is touching the carpet in the goalie zone their 6" diameter blocker can be anywhere they can legally reach.
That's what I got from it too. The more interesting challenge is designing a mechanism that can a) extend 20 inches past the frame perimeter, and b) withstand repeated impacts of the ball at the very extreme of 20 inches out and probably at least 40 inches up.

When we were considering a pure goalie, we wanted to exploit the fact that the rules actually don't impose any height restriction at the beginning of the match, so if you start in the goalie zone, the blocking post doesn't even need to be retractable, which means the vertical blocker can be pretty strong. We also designed a two-way horizontal linear elevator based on 118's 2011 robot, which would have easily been able to take the impact of a ball. However, the weakness we encountered was that the goalpost acted like a wrench, with a huge mechanical advantage.



We stopped working on it around then because the mentors wanted to build a very different robot, but by then we had figured out that a blocker that could extend over the low goal is a major feature, and would mostly dictate the rest of the design.

tl;dr In my opinion, extending over the low goal to block the ends of the high goal is a difficult feature to implement unless the entire robot is built around it [and even then, it wouldn't be easy].

EDIT: Ooops, I forgot to mention: team 1710 executed this beautifully, and because the axis of the hinge is perpendicular to the torque above, they can easily withstand the impact of a shot. Bravo to team 1710!

Last edited by ohrly? : 04-03-2014 at 16:49.