I all, Arducoter thrust and lift force problems at hight altitude ???

My question is: My 3DR have to flight between MSL 2000M and 4000M for scientific missions (bio-diversity monitoring in Alp contest). I make the first test yesterday, and my 850kv + 10/4,5 prop and 3S 2600mAp 30-45c, where not enough to lift my drone at ALT MSL 1900m (at the end i brake some blades and ouch... ;-( . So i'm trying to find a solution like 4S and 12/4,5 or 11/4,7. I studying with "drive calculator" but no one as putting into the program the dates for it. On other hand i did not find precise datas about 880Kv and 12/4,5 and 11/4,7 propellers too proceed with calculations.

May somebody help me ? BRGDS Olivier.

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  • Hi Oliver.

    I find this very helpful to play around with. http://www.ecalc.ch/xcoptercalc_e.htm

    You can change motors props and batteries untill you find a solution.


  • Hi Olivier,

    I am also testing ArduCopter quads at high altitudes. I have flown the original ArduCopter 1.0 (before 3DR made a frame) and had good success with it on Mt Erebus, where the air pressure was about 650 kPa. See http://youtu.be/JYHDX6IE9-A and http://youtu.be/e9YYZ0SWWWI . It handled quite well with no modifications to the code or PID values.

    Recently I flew an xaircraft 850v frame, esc, and motors controlled by an APM2 board at 12,300ft in Ecuador: http://youtu.be/ADZA-znfQ3c . I found it more difficult to control in the air -- it was not unmanageable, but the response was sluggish and it flew "drunken." Probably could have turned up the P values.

    I have spoken with people who advise me that for efficiency in thin air, we should be using relatively higher pitch propellers and that idea makes sense to me. I have not tried this, but would like to.


  • Hi Olivier,

    Torino....sei italiano?? direi forse francese...Anyway, I guess you could need to change also the propellers...you will need more thrust, i will suggest you to use more powerful engines with at least 12x4.5 props.

    I have en hexa with which I'm planning to take aerial pictures...and I will have an additional 800 grams payload (2 cameras, 1 rgb and one nir). I have engine 880 kv and 12x4.5 props, plus 2x3300 mha 3s lipos.

    Change your engines with bigger ones and use 12x4,5 (30A esc)

    Which kind of sensors are you using?





  • This's the E-calc for hight altitude flight project.

    I hope that AEOLIAN motors are those solded for 3DR.

    This is the only one with same specifications.

    Best regards Olivier

    xcopterCalc 4S 6000mAh.pdf

  • Have your tried using a bigger prop like 14"? 

    Anyway, this calc might help:


  • This is a pretty interesting situation! I wonder if an adjustment to Stabilize_P would help in the stabilization in lower air densities?

    I agree with Randy though, a 4s should do the trick.

    Maybe you can add Jani as a friend and PM him on this site

  • Developer

    I can't really help you much but I'm slightly interested in what you're trying to do...

    So it couldn't even get off the ground...or you reached a certain altitude and it refused to go any higher?


    I'm pretty sure if you go to 4S and the 880kvh motors it will be have so much power you won't have any issues at all.  Probably just the 4S batteries alone will make your problems disappear.  If that fails, try 5S!

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