An idea for the 2000 games..(is six weeks enough?)

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Posted by Dodd Stacy.

Engineer on team #95, Lebanon Robotics Team, from Lebanon High School and CRREL/CREARE.

Posted on 7/30/99 9:53 AM MST


In Reply to: Re: An idea for the 2000 games..(is six weeks enough?) posted by Kyle Huang on 7/30/99 3:08 AM MST:



:

: 'My point (or maybe it's a complaint) is that giving specs of game objects at any time doesn't necessarily
: help out. in 1998, what if one of the balls hadn't been filled up correctly? It could cost a team valuable points.
: The problem with that, is that there's almost no way to make sure everything is exactly the same... hundreds
: of floppies/balls/inner tubes go out to teams across the country, then hundreds more are used in all the
: regionals and in the nationals. How can FIRST make sure every floppy is filled up with the same amount of
: peanuts, that every ball in competition is inflated perfeclty... I'm sure there are other little issues involved...'

Kyle,

Your experience with the floppies is a case in point. If we had all made or purchased a dozen or so floppies
ahead of time and 'played' with them, we would have found out how much volume variation there can be in a
fixed weight of styrofoam peanuts, and how much the peanuts would compress/degrade with some physical
abuse.

Last year, the balls demoed at Kickoff wedged very firmly between the ladder rails. Once stuffed, they were
virtually impossible to dislodge by hitting, pushing, or poking. When we received the 10 or 12 balls we ordered
and inflated them to the specified pressure, we found the diameters to vary by +/- 2' in that small sample! All
were loose in the rails - some dropped through under their own weight! We found that the shapes were highly
variable, from spherical to egg-shaped. We also found that the weights were quite variable, and that the shape
stiffness was variable at the same inflation pressure.

FIRST ultimately refined the spec to include both an inflation pressure range AND a diameter range. By that
time, we had already committed to a strategy based on wedging the balls and developed the manipulator to do
that. It was slow, but worked killer with the big, hard demo kit pressure spec ball. With the final spec, the wedged
balls were easy for the opponents to knock out of the ladder, and our offensive strategy was thus easily defeated
by a quick opponent. I believe that, had we all gotten the balls early, we would have collectively surfaced these
issues and resolved them with FIRST well before the design/build/develop crunch. At the very least, we would have
been able to quantify the variations in a typical sample of the game objects and to develop manipulator concepts that
were sufficiently tolerant of those variations.

Dodd
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