pic: Team 488 Presents X

Find all discussion about this robot and the other photos of it in the associated discussion thread.

"X" is the result of a partnership between Seattle Public Schools, Franklin High School, and Microsoft.

Team 488 is proud to unveil X, its entry into the 2005 FIRST Robotics Competition. X takes the old adage of “KISS” to the next level by marrying simple mechanisms and components in quantity to produce outstanding results.

We decided early in the season that we were afraid, frankly, of the complexity of a device that could acquire, store and score multiple tetras at a given time. The effort required seemed to have very little payoff with respect to scoring and machine reliability. Instead, we thought about constructing a simple, reliable device that could grab and score a single tetra at a time and felt satisfied that such a strategy would perform well at the Pacific Northwest Regional.

As it turns out, building two of something really isn’t that much more difficult than building one. I invite you to meet Bonnie and Clyde.

Each arm rotates approximately 60* via the actuation of a single 1.5" bore, 11’ stroke piston in less than 2 seconds. The two positions we provided for line the arm up perfectly for acquiring tetras from both the human player and the automatic loading zone as well as scoring tetras on the outside and center goals.

The arms are two-segment, telescoping devices driven by a chain coupled directly to the output of the provided window motors. To reach its full length, each arm takes approximately 6 seconds. The spring loaded tetra grabbing and release mechanism attached to each arm offers an addition 24" of reach and ensures that we do not need to telescope to score on any but the center goal, making scoring fast and efficient.

When lowered to their horizontal position and fully extended, the overall length of our robot shifts from 38" at the start of the match to an astounding 212" (17’ 8"). This makes the robot effective in defense as well as offense, though we understand the limitations on our defensive effectiveness as a result of the immensity of the structure in that position.

We store air in two Clippard storage tanks and can actuate each arm to grab and score a tetra simultaneously. An onboard compressor quickly replenishes the air supply.

The drivetrain uses the provided KitBot gearbox with a modified chain reduction as its final stage. We are using 6 Skyway Wheelchair wheels taken down to 7.5" diameter with a slick tread for maneuverability. Our center wheels are lowered 3/16" from the outside wheels. Our top speed, under load, is approximately 7’/sec.

The students had some doubts about the robot and its design after seeing many of the area teams field completed robots at a Saturday scrimmage. After a long night Monday, they were exceptionally proud of the work they’d done when “X” came to life for the first time. This machine is, without a doubt, the best robot I have ever worked on in my seven years’ involvement.

Your comments and questions are welcome and appreciated.

Cool. I finally get to see a robot that we will be partnering/competing with in the PNW regional. I think I’ve seen two 2-arm robots here on Delphi. I have officially smacked myself on the forehead, “Why didn’t I think of that?” I am looking forward to seeing it in Portland.

You were sandbagging at the Bellevue event, weren’t you? :wink:

I was only at the event for about 45 minutes, so I wasn’t doing much of anything at all, really – unless by “sandbagging” you mean, “You were nearly killed by several robots overrunning the field,” in which case, yes; yes, I was.

We’d originally planned to grab the tetras along the bottom so that we could stack one or more atop the tetra in the grabber, but that design became too complicated to work reliably. Instead, somewhere in the midst of week three, we stumbled upon the grabber we’re using now and we’ve been very happy with its uses.

I’m attaching a fourth photo (in addition to those uploaded in the Gallery) that better illustrates the independent operation of Bonnie and Clyde.

very nice…see you guys in Portland!