Flying into the record books
After finally getting the license from the Norwegian Aviation Council, we got a deal with the Cutting Egde festival in Oslo to showcase the drone and try to break the record. Guinnes told us to lift at least 60 kilos to set the record. It sounded like an easy match, as the megacopter had easily lifted 70 kilos on tests. However, we learned the hard way that the location did indeed matter. For safety reasons and Murphy´s law worst case scenario, we decided to fly iside a pit, some 4 meters below the floor where the audience was standing.
It looked like a perfect location, but later we discovered that wasn´t exactly the case.
Crew members down at the pit
We did some trial runs before lunch and a live broadcast the the Norwegian news station TV2 Nyhetskanalen. Things went pretty smooth and it was exiting to fly "live", allthough no extra payload made it simple for me to steer the vehicle. Then we charged all our 24 batteries, which took about 2,5 hours and waited for our big record attempt at 17:15 as the final event at the Cutting Egde festival. We brought out the batteries and started connecting them. The crowd started gathering and soon there were people all around us upstairs. The Norwegian Metrology Service arrived with highly calibrated weights and and a scale, and people from the publishers of Guinnes Book of Records were also present.
Batteries, regulators and clumsy bullet plugs. Read all the technical details on how we designed the Megakopter here.
Bullet plug problems
Our biggest mistake during the whole design process was to use bullet connectors (the red plugs above). The male and female plugs identical, thus making it possible to short circuit two batteries against each other. Because we, the crew members were a little nervous, we managed to connect two 22 volt batteries against each other instead of into the speed controllers. Poof! And we had two batteries burned and plugs welded to death. Fortunately we had back up batteries, so this was not a disaster. New batteries was mounted and we took a test spin with the motors. One of the motors didn´t spin! We had 48 motors, and now only 47 of them were running. To replace the ESC we would have to solder new plugs, so we just took the change with the 47. People downstair were told to take cover behind a fence and we were good to launch. I armed the KK2 flight controller and lifted off. I kept pushing the throttle higher and higher, until it was almost at 100%, and the megacopter climbed slower than usual and was now very hard to control. With all the motors running nearly at 100%, there were no room for stabilizing any more as it would require some motors to run even faster.
Why was it suddenly so hard to lift 70 kilos? I didn´t know at the time, but we had to do a landing after just 15 seconds. Guinnes required 30 seconds - so no record yet. We replaced 10 kilos with 1 and did another try, still with one motor missing out. I noticed there were more power and headroom now, but then the Megakopter started to wobble heavily and again I had to land before the 30 second limit. It turned out, the turbulence down in the pit was quite bad. Instead of escaping to the sides, the air had to get back up, creating whirlwinds and vacuums. We decided to repair the broken ESC to get the drone better balance. The spare ESC didn´t have the right plugs and the crowd was getting unpacient, but we decided to focus on the record itself and take the time to fix a new plug. According to the evidence video, some 13 minutes later we had did the overhaul and now were determined to crack it. I kept telling myself "it´s just an RC drone, no problem" and took off again. Our machine did well this time and at 17.50, just ten minutes before the permit was out, we did 37 seconds in the air and the record was finally ours! You can see the flight for yourself below.
We got approved at January 19, 2016 and got the official title "Heaviest payload lifted by a remote-controlled multicopter." Despite different large hobby drone projects already have appeared around the world, nobody had actually done it by the rules - we were the first and I think it´s something for the whole team to be proud of and remember.
Proud record holding team.
From top left: Krister Borge, Kine Eide, Benjamin Ormseth, Markus Limseth, Karl Tomas Hauglid, Bao Marianna Ngyen, Jørgen Gamre.
Front Row: Roger Antonsen, Kim Bjørneseth and me, Henning Pedersen
See more blogs and news posts about the Megakopter from around the world:
A nice outdoor flight from a TV performance with the Norwegian Broadcasting:
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