SMART's BrickCon Display

I want to thank everyone who participated in this year's SMART display at
BrickCon. It was absolutely amazing! We couldn't have done it without everyone's
help. Every element was crucial, and worked amazingly! Named "BallMageddon"
because either it was going to be a catastrophic failure, or a spectacular
exhibit that everyone who saw it would remember for a LONG time! I'm very
pleased to say it was the latter!

Here's who contributed:

Gus designed the display and an amazing 'wave' that carried the balls in front
of the display.

Kyle built the final lift that brought the balls into the display, as well as
the sorter that took the balls coming out of the display, and returned them to
their proper bins.

Andrew built the "rainbow stairs", one of the two most commented on parts of the
display, which took the balls coming out of the display and gave them their
initial lift to get them rolling towards their destination.

Sean built a wonderful ball escalator that took the balls from near ground-level
and got them all the way to the top of the bins where they got sorted by Kyle's
sorter.

Of course the wonderful and beautiful hoppers built by Dan were essential. I'm
not sure how many versions he built before creating one that wouldn't jam. Now
he understands the many ways that balls will form voids when you try to pull one
out of a pile. I'm not sure that he entirely believed us when he volunteered to
build the hoppers. Also worth mentioning here is Doug's interesting pattern to
stretch bricks to allow such large bins to be built with a limited supply of
parts. And equally important was Alex's contribution of building pushers to get
the balls onto the conveyors! Thanks to this vital improvement, we didn't have
to stir the balls constantly to make sure that we had the constant supply of
balls we needed!

I built the display generator, and want to thank Craig for the suggestion of
rejecting balls by default.

Craig built one of the other much-commented on part of the display: a wonderful
rotating loop that lifted balls. He took the advice that the public loves to see
interesting motion, and that the most interesting part of the display is the
motion the balls go through to get to the display, which only provided a
rationale to the balls movement.

Craig also built a wonderful arm that took the rejected balls and returned them
to be sorted. Unfortunately we couldn't get this working on Saturday, as there
were so many other problems that needed to be solved first, but Craig got the
arm working very quickly on Sunday, and it worked like a charm!

One part of the display that didn't officially make it into the display proper
was Mark's balancing, ball-carrying robots. Originally the intent was that these
robots would carry the reject balls from the display generator back to the
sorter (a role that was taken over by Craig's arm). But Mark wisely recommended
that with two extremely complex and error in-tolerant displays, it was better to
separate them and get them working independantly. At some later date we can
combine them. In any case, Mark DID get his balancing robot display working, and
it was equally interesting to watch! I look forward to seeing how this part of
the display evolves in the future.

With a display like BallMageddon, the balls need to be 100% reliable on their
path from the generator to the display board. One lost ball will shift the
entire display, and just two lost balls will result in an incomprehensible mess.

So I want to provide a final and very heartfelt THANK YOU! to Gus for all the
debugging in getting the display working reliably over the weekend. It started
off requiring constant human help to continue working. By early Sunday, though,
it would run for hundreds of balls without any error at all.

Thanks again, to everyone who participated, and all your wonderful devices! I've
thrown together two videos of our display. Please check them out:

http://www.youtube.com/watch?v=2jeioJzvNe8
http://www.youtube.com/watch?v=ITt-zFTKFXI

--
  David Schilling