Today I flew my Cyclops EPO for an incredible 7 hours and 8 minutes, covering 301 km (301 km !!!) in one flight.
After flying my Maja for 126km I decided 200km would be my next challenge. I got the Cyclops with that in mind, it was very very efficient straight out of the box and after my first flight test I realised it was capable of much more.
I did 5 flight testing sessions where I tested different speeds, C of G positions and propellers. The data from my last two sessions suggested 300km was possible with good conditions so that became my goal.
I planned my mission with a couple of waypoint path options that I could switch between using do_jump. After a hand launch I switched to auto for a very gentle climb reaching 50m of altitude over about 2km. I flew a few laps of a 2.5km lap, before switching to a 3km lap and then a 3.5km one which used a do_jump command to fly continuous laps at 60m altitude.
To monitor my progress I’d made battery consumption schedules for 250, 280 and 300 km. My calculations said that I would need to run my batteries down to 10% remaining to reach 300 km. The first half of the flight was very calm and I was ahead of schedule. But the wind picked up in the afternoon and it became apparent that I might finish with less than 10%. I tried to help the situation in the last hour by varying my speed around the lap. I flew at 14 m/s for the head and cross wind sections, and dropped to 13 m/s when I had a tail wind. I hadn't done any calculations to support that, it just seemed that I could make the most of the tailwind section by dropping my power there a little.
I’d decided in advance to end the flight when the battery dropped to 12 V (3.0 V per cell) and I could see as I passed the 280 km and 290 km milestones that it really was going to be tight. The voltage was hovering either side of 12 V as I approached the 300 km mark so I knew it was time to bring it in, but I also knew that Mission Planner can underestimate the distance compared to the GPS log. I decided to fly to 303 km to be safe. The way the laps worked out it was 305 km when I hit the ground, and just as well because the GPS log came up as 301 km. If I’d come in when Mission Planner told me 303 I would have been member of the 299 club.
The telemetry log file is 47 MB (linked below) and Mission Planner crashed when I tried to create the KML file (I tried on three different machines). It did manage the GPX file thankfully.
Key specs:
- Cyclops E with V-tail
- APM 2.5
- Panasonic 18650B Li Ion batteries. 4S7P, 23,800 mAh
- Aeronaut 11x9 prop
- Hobbyking telemetry
- Distance covered: 301km (according to GPS log file, 305 km according to Mission Planner)
- Flight duration: 7 hr 8 min 10 sec
- Average groundspeed 41.7 km/hr
Comments
Panasonic NCR18650 batteries from this supplier provides then wrapped in a variety of configurations from this
eBay store (Free Shipping too) hunk_lee (Excellent eBay ratings)
I've seen many configurations of them but with that many cells, I'm curious to know what it will look like.
I might test the Talon as I built a liion 4S7P pack for my 1h15min quad flight (23800mah). I'll post some results.
I'd love to know. I've heard that the Talon is quite versatile. I've looked at it myself, but I don't think it wing is high aspect enough for real high efficiency flight. The cyclops by comparison has 2.6m wing.
Very impressive. How do you think a XUAV Talon frame, with wing extensions (2m wingspan) , same type of 700Kv motor, 12" prop, same battery (LiIon 4S7P) would perform versus this cyclops frame you flew?
They were LiIon batteries not LiPo, and they are fine, I'm still using them.
Excellent work and really great reading mogios, do you have another record planned ?
The ESC was d-lux from hobby king. I picked it because it was switching not linear which is more efficient (or do I have that the wrong way around).
It might actually handle 6S too, I'm not sure.
I spend hours and hours in ecalc finding the best motor specs for my chosen power and airframe, then hours more trying to find an actual motor that had those specs. The simplest would be to look for a hacker from the same family but with kVa that is 4/6 of the one I used to get the same RPM
I thought about 6S and yes I expect longer flight times. Lower current at the same resistance equals lower losses, but the advice I had was that it would be minimal. I didn't attempt (or even know how) to calculate how minimal. It would have meant re-configuring my batteries, esc, APM power module, motor etc so I decided it wasn't worth the effort.
No build log sorry. I followed instructions on RC groups. CG was right on on the main spar. I tested 1cm forward and back from it and found right on the spar to be the best.
Most specs are listed at the very bottom of the main post. I missed listing the motor which is a Hacker A30 52S UAV.
I used 4S because that would work with all the stuff I already had.
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