Photo courtesy of the San Jose Tech Museum
We went to Tech Challenge with a fully functional airship, that had gone through two full cycles of testing, and with drivers with a few days of practice. We were as prepared as we would ever be.
That morning, we saw all kinds of devices. Lots of people had created gliders and planes to reach the top of the volcano. We also saw plenty of towers and crane-type devices, which would (most of the time) be pushed up to the volcano. There was even an FRC chassis, made out of extruded aluminum, with a rig set up on top and ready to roll.
We even saw a couple of blimps around – they all looked rather similar to off-the-shelf blimps, though – and there were also a few RC helicopters. It looked like we had some competition.
Our first run at the volcano during judging took one and a half minutes because we overshot. One “sensor” (ping-pong ball) landed on the bottom ring of the volcano; the other five on the top. After reloading and getting approval from the judges for a second flight, we go for the volcano again. This time, it took 30 seconds. All six sensors on that run landed on the top. After we knocked off two of the sensors with our propellers’ thrust, we ended with a total of 9 on the top platform in just about 2 minutes.
For our presentation, we had created a 20-slide PowerPoint. We also came prepared with all the designs and sketches we had made at the beginning of the year.
Afterwards, the whole team went outside and flew our device for a while to celebrate what we felt was a really good run. We loaded our everything onto Mr. Brucker’s car again and waited for the awards ceremony to begin.
Our device’s performance as well as presentation earned us the grand prize for Best Overall Solution, the top award of the competition.
Competition day is getting close! We found out that the airship actually works really well. We practiced for most of lunch in the school auditorium. Later, we met after school in the cafeteria with a mock volcano and drop area, made of trash cans stacked on the cafeteria tables. We managed to make a round trip with a successful drop in as little as 27 seconds – looking good!
After we attached additional balloons to achieve near neutral buoyancy, we tested the blimp some more, and switched the control scheme to a tank drive, to make turning easier. We also added a second transmitter – another 5-channel one – so now we’ve got a full ten channels running the blimp.
Now we’re getting ready for tomorrow: Eric is currently organizing boxes. Raymond is finishing our presentation. Catherine is working on our banner, shirts, and hats. I (Rebecca) am finishing documentation. Tomorrow is the big day! We’ll see what happens soon…
There’s one week till competition!
Today, Rex shorted out a wire and burned both herself and the wire, and the plastic coating melted. It’s a rite of initiation for us roboticists.
Raymond soldered ESCs using circuits from servos we took apart last week, and set up a Y-cable for powering everything we had so we could run it off one battery. Rex and I worked on attachment of the frame to blimp, deflated blimps, and constructed tabs to attach the blimp envelopes to the airship frame. Catherine and Rex (but mostly Catherine – she says it was a workout) pumped up the non-helium inflated balloons with regular air to hook up a method of attaching the blimp to the frame. Yay for packaging tape!
Piloting team all on one controller
Went to the last trial at the TechMuseum on Wednesday. It didn’t go too well. The blimp was flyable, but we were only able to get the ping pong balls on the lower level at the very last second. Literally. They called time and we got the ping pong balls out. Need to get that fixed. Raymond and Eric will probably do some crazy last minute thing to make the blimp easier to fly.
Practicing at the TechMuseum after our trial run on the volcano. Raymond is holding up our “target”
Discussing what to do next
Today we moved to Rebecca’s house, and we’re now working with only three people, since David left for spring break and Eric is busy. I worked on speed controllers, taking apart the servos and preparing wires to solder on, and Catherine and Rebecca worked on a frame, attaching motor mounts, which were basically vertically oriented pieces of carbon fiber that we could tape and glue the motors onto. We finished compiling designs for speed controllers, and soldering will begin tomorrow. ESCs are 75% done and we expect to finish the other 25% tomorrow.
We also reinflated the two backup blimp envelopes with air, and rebuilt the harnesses with yarn after they were damaged (It was windy outside!)
