Last month I detailed my plans and preparation for an attempt at a 100km flight in a blog here.
Well yesterday the weather was ideal and my preparations (nearly) complete so I went for it and achieved a flight distance of 126km in a time of 2 hr 46 min 40 sec.
I can't attach my log file here because it's too big. It's 15MB and there's a 7MB limit. Any ideas how I can share it?
I exported the KMZ (2014-01-28%2006-32-40.tlog.kmz) to Google Earth and generated the following images showing the flight path, and the altitude/speed trace with some of the vital statistics.
[Click image to enlarge]
The airframe is a Bormatec Maja with 2.2m wingspan. It’s not the most aerodynamic airframe, but its advantage is its payload capacity which allowed me to carry 21600 mAh 6P4S Li Ion batteries with ease.
I stripped out absolutely everything I didn't need including the obvious things like FPV cables in the wings, and thanks to some advice on my previous blog I also removed a few things I wouldn't have thought of such as the RC receiver case and airspeed sensor.
The advice I had from other DIYDrones users was invaluable but the biggest factor in improving the performance was the testing I did. For each variable I wanted to examine I would fly multiple laps at different settings then analyse the log files to find the best performing setup. I give more details on that in the original blog.
For the actual record attempt there were a few things I’d never done before. One was flying without the airspeed sensor (I had flown with it switched off, but never with it physically removed) and the other was the 4 cell batteries. Probably both those things were the cause of the trouble I had getting the plane to fly at the 13m/s (47km/hr) I wanted. Initially it was much too fast. Over the period of a few laps I adjusted the cruise throttle percentage, the cruise speed and the min and max speeds to much lower than I really wanted which bought the speed down (and pitch up) to where I wanted it.
Key Stats
• Distance: 126km (according to Google Earth)
• Duration: 2hr 46min 40 sec
• Airframe: Bormatec Maja
• Wingspan: 2.2 m
• AUW: 3.25 kg
• Battery capacity: 21,600 mAh
• Average Speed: 45.6 km/hr
• Top speed: 68.3 km/hr
• Minimum speed 40.5 km/hr
• Duration: 2hr 46min 40 sec
• Barometer creep: -6m
Comments
Hard to say Gary. Not many people have been looking at this. Always hovering flight time records, but IMO, distance is pretty important too. IMO, if your flight performance could be easily bested by a long pole, it's not of much use. ;)
10km should be pretty easy, even for a multirotor. But nobody has recorded it yet so... a good starting point? I think I've already done 20km with my big helicopter, but didn't record that.
Most Excellent!
You can get a free dropbox.com account that will be big enough to host your log files.
@Rob yes I think we should make a heli badge, what would be a good distance for a challenge? 10km / 50 /75 ??? I have no idea what would be hard for a heli.
Congrats Moglos!
It was great to read your post about the preparation and finally the success :)
Good work Moglos and thanks for sharing.
Gary: are there distance badges for (heli)copters?
Wow that's really great! BTW I've clicked on your other link, astonishing that it is done with a "Maja", after seeing the "mygeekshow" progress I thought that these distances were just possible with deltafliers. I've read in your other thread that "EPP surface isn't very smooth so I want to cover the wings (I've got some CP Laminating Film - 1.7 Mil on the way)." Since I want to get my little plane also airborne (one fine day) and don't know very much about planes I have a question. I have heared some experienced "plane guys" talking "oil" at the RC airfield so I talked to them. They claimed that a little roughness on the wings was actually good for the flightbehaviour (no talk about flighttime), and that their efforts to make the plane surface as slick as possible in the past produced actually worse results. Well I don't know the physics behind that, but maybe little turbulences on the wings can actually "help"? It's hard to imagine, but who knows. What is your before/after experience? Just curious.
Cheers Rob
Impressive: which version of the code were you using?
congrats! for one of the longest continuous flight on these blogs. can u share the param file. i
Was this with the Panasonic batteries?
Congratulations it was a very great pleasure to award your badge ;-) The result of hard work and planning top notch!
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