Went for our long distance flight attempt today, flew a test flight with a 6S 2600mAh LiPo and then put in the 18650 batteries in, the log unfortunately shows both flights as I forgot to reconnect so I have calculated the time and total distance from the launch of the second flight to the landing.
Basically we did a 300m diameter Loiter for most of the flight, biggest problem was the phugoid motion of the plane losing height on every downwind leg and having to regain the lost height on the upwind leg using precious amps to do so. I tried just about every parameter to tune the plane better throughout the first hour but could never get it to behave.
Special thanks to the devs (especially Tridge and Paul Riseborough), to Steve B. for assisting and UAVDS for making it possible
Plane: Super Sky Surfer
AUW: 3078g
Motor: Maytech MTO3548 790Kv
Prop: APC-E 9x6
Batteries: 6S4P NCR18650b 25.2V, 13600mAh
Battery weight: 1172g
AutoPilot: APM2.5, APM:Plane v2.78.
Weather: Calm (0-4km/h), clear blue sky, 26°C. Altitude: 1668m ASL
Time flown: 126m 53s
Total Distance flown: 116.475km
Calculated consumption on nominal capacity: 115mAh per km (will update after recharge).
Estimated current draw: 5.2A average
Lowest voltage on pack 18.0V
Average speed: 55km/h
Droneshare: http://www.droneshare.com/view/bfgodhs
Tlog: https://db.tt/UfVPiyBE (12MB)
KMZ: https://db.tt/1Tmzim1W (3MB)
Comments
As a fellow SSS owner I say Well Done!
Hi Graham looks like a pretty consistent circle considering drift from the wind and acceleration and deceleration on the downwind and up wind legs with that distance achieved you could send the plane on a"mission!" just a bit off topic I was watching the Olympics and I thought I saw a Hex or larger hoovering over the top of the snow board hill.Good Luck on your next Endeavor and Have a Great day!
i did measure this way myself with GoogleEarth
But wondering how can you do that with Mission Planner? I know when you prepare a mission, you can see the actual distance, but how can you see the real distance from log or tlog?
looks like the sweet spot for duration with this plane will probably be at least 150 minutes duration when every thing is optimised. Flying the mission with 60% straight and level will also help.
With each segment of the flight, if you right click you get a box, one of the options is 'Elevation Profile', this gives an elevation profile obviously but also shows the distance for that leg.
mAh per km is not a good measure since voltage is also a factor...
Wattage gives you a better idea of efficiency...
Anyway taking into account that You were flying in constant bank, thats not that bad ;)
But when you think that for instance a Human Powered Aircraft uses 175-220 for sustained flight ;) and it weights 80kg and has 25m span...
Anyway I think a faster aircraft would give you more km per W :P
Thanks for the thoughts on battery holders Graham - I am going to abandon my idea of "recycling" batteries I already own. I really dont want hassles with broken connections!
Good questions, Wojciech. This was a "see if I can" rather than a meticulous record attempt, we have other goals, distance/duration is just one of them.
The largest prop that can fit on this plane without modification is 9-10", however lower Kv motors for a larger prop and motor adapter plates are on their way, should be here next week. I'd like to use the highest practical cell count, lowest Kv motor and largest practical prop I can.
I'd say 115mAh per km is VERY efficient, the other two 100+km flights I know of used <160mAh per km. Ours will probably be even lower as I estimate I only used 12000mAh so that's 103mAh per km!
This 3kg plane only needed about 125W average over 2h06m!
This seems to be somehow inefficient...
Why 6s battery? it seems like a 4s would be a better choice for this motor... Why such a small prop? Why this motor anyway?
I'm not sure what protection these 'protected' cells have, it may be something one can just remove?
I would never use battery holders, I have visions of the problems I had with AA cell holders, the risk of a broken connection is just too high not to mention the electrical resistance. Spot welding uses a very short high power surge to weld tabs onto the cells, just about every laptop's battery is prepared this way.
Some people have just soldered copper braid onto the cells to join them, they solder very well in fact.
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