Jammed Ball Bin-Storage Help!

[=Martin=Taylor=]

At the Silicon Valley Regionals our team had problems getting the balls to come out of our bin.

The bin was gravity fed with no agitators. The bottom and sides were both sloping, directing the ball towards our 1pt shooter.

(You can sort of see it in this picture)



The problem occurred when 3 balls would try to exit the shooter at once causing a triangular pattern to form.



We fixed this at the regionals by simply jerking the robot back and forth to loosen the balls. This is fine, but it makes aiming difficult! I'm hoping to design a new bin in time for nationals that will solve the problem but I'm not sure what to do.

Agitators are out of the question because additional motors would require additional programing and wiring, which we don't have time for.

Here are my ideas so far...

=>Note that the ones labeled 1,2 & 3 are back views looking towards the front of the robot.<=



Which do you think is least likely to jam?
Have any better ideas?
What did your team do?