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
Published on
April 12, 2009 in
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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!)
This month, carbon fiber and motors and propellers arrived! We also obtained a box of servos, and we’re planning to construct electronic speed controllers using the controller boards from servos – we’ll solder a fixed voltage divider in place of the position feedback potentiometer on the servo control board, and then we’ll switch out the motor that drives the servo for one that will drive our propeller.
At Hobbytown discussing what to buy. Raymond is on one phone, Eric on the other.
Published on
February 22, 2009 in
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We ordered carbon fiber and blimp envelopes (shouldn’t this have been done a month ago?) When the blimp envelopes arrived, we inflated them at the grocery store. The carbon fiber still has not arrived, so we did more design work and ordered servos for the drop mechanism.
We also ordered motors and propellers.
When carbon fiber arrives, we’ll construct basic carbon fiber skeleton frames.
Published on
January 27, 2009 in
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We continued sponsor runs and materials procurement. In this economy, getting any sponsors at all is extremely hard. =.= We obtained a used Blade CX2, a Futaba C7 transmitter, and a receiver set; while testing, Futaba receiver shorted and burned out. There goes a hundred dollars. =(
Published on
December 31, 2008 in
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For posterity’s sake, here is the initial plan we wrote up for Tech Challenge:
For Tech Challenge 2009, we have decided to solve the problem using RC blimps. RC blimps are stable, easy to control in restricting areas, and have sufficient lifting capacity.
As such, we set out to design an RC blimp. Due to weight constraints and strategy we have decided to fly two RC blimps, each splitting the payload. We will construct both RC blimps with carbon fiber frames. The helium envelopes will total 14 cubic feet, and made of Mylar. Two RC transmitters will handle controls, both using 2.4GHz technology to avoid interference on competition day. Ducted fans will provide propulsion, controlled by servo controller boards modified to be electronic speed controllers. We will power the whole device with LiPo batteries.
One blimp will carry 4 payloads and need 5 channels. 1 for the Vertical axis, 1 for the Forward and Backward control, 1 for the rotation of the blimp, and one to “strafe”. The controls will be set up to be helicopter style, cyclic and collective. It will also use one servo as a payload release servo.
The second blimp will use 7 channels. Again, the movement controls are the same. There will also still be a release servo. The remaining two channels will serve as a pan and tilt control for a micro camera, which we will use to provide a closer view for the release, so that we will avoid depth perception problems.
We will have two blimp pilots, each flying one of the blimps. Another two team members will be visual spotters, guiding the pilots for controls and taking over if anything goes awry. The final member serves as a TV spotter, covering the 2.4GHz camera.
Published on
November 2, 2008 in
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Today, we drew designs and decided between these four designs:
- Helicopter – low capacity, lowest stability
- Single Blimp – highest stability
- Multi-Envelope Airship – easiest to control, highest stability
- Multi-Envelope Hybrid Airship – highest capacity, medium stability, medium control and maneuverability
Our final decision was to build an airship that would be stablized with two blimp envelopes. We performed some calculations, and figured that we would be able to lift at least a few hundred grams with the two high lift envelopes that we found on the Internet ($25 apiece!).
Published on
October 30, 2008 in
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Throughout October, we went through different designs of airborne vehicles. Raymond and Eric both bought RC helicopters off Craigslist – we were surprised how inexpensive they were these days – and tried flying them around, without too much success. We also tried flying a remote-control glider, which didn’t work too well either, even though it didn’t travel very quickly. By the end of the month, we had decided that we would build an airship of some kind, that would be lighter than air and easier to control than a helicopter or airplane. We hoped to have separate channels controlling lift and thrust on both sides, and possibly also have thrust vectoring built in, as well as a servo to release our “instrument packages.” To these ends, we decided to purchase an assortment of small servos, and the nicest radio we could find.
Published on
September 24, 2008 in
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Over the these weeks, we made a list of the things we think we will need to buy for Tech Challenge by conversing back and forth over email. Also, we’ve basically decided that we will build something to fly to the target zone, in the spirit of volcano exploration. Here are the estimates:
- Airplane or helicopter: $400
- Camera or some other autonomous system for targeting: $200
- Team shirts and banners for sponsors: $100
Eric drew up a whole bunch of designs for blimps. We also decided to begin finding sources of funding since this year’s challenge would be somewhat costly.
Throughout September, we met during lunch in Mr. Brucker’s room. We tried our hand at sponsorship by visiting local companies and offered advertisement services in exchange for funding. Got $100 at Learning Bee and $100 at Martial Arts, located in the plaza of Lucky’s, Fremont. Learning Bee agreed to sponsor us if we presented our device afterwards. We think quite a lot of tutoring places will be willing to give us money if we can demonstrate our device to their students.
Published on
September 20, 2008 in
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We’ve gotten through the beginning of the school year, so now we can start working on our projects. However, we didn’t get a lot done today. We talked a lot about what we were doing this year, since there were a few competitions coming up soon, including a science competition for Catherine and a robotics tournament that Raymond and Rebecca were going to. We decided that we liked this year’s challenge – it would give us a chance to work with electronics and build a control system. We also realized that it would cost us quite a bit of money if we were going to use electronics. Afterwards, we talked about the year’s schedule for Tech Challenge, and drew up this list of what had already passed and what we were going to do:
- August
- The challenge is released, and we’re all finishing up summer vacation. Quite a few of us were gone over summer so it wasn’t practical for us to meet then.
- September, October
- We’ll all have a lot to do since we’re starting junior year.
- Start brainstorming throughout the first few weeks of school, and think of crazy ideas that just might work.
- November, December
- Focus on getting sponsorship and finding some good (and inexpensive) sources for what we will need. Try to get in-kind sponsorship for anything we may need in quantity.
- January
- Revise and finish first design
- Procure all our parts and test them individually
- February
- Assemble first testing airship
- Inflate blimps and test
- Correct flaws in design
- March
- Complete both airships
- Find a site for practice and practice with both airships
- Decide on who will be controlling the airships
- April
- Finish early and work on team spirit!