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Cinestar 8 Upgrade for Medium Heavy Lift (8-10kg)

Discussion in 'Cinestar 8' started by Steve Maller, Jan 3, 2014.

  1. Steve Maller

    Steve Maller UAV Grief Counselor

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    Here are my hover numbers for one of my flights today...7.5 minutes flying mostly manual with the MōVI M5 and GH4 on board, plus two 8000 mAh batteries. According to Holger, I used 8500 mAh during the flight. Landed at about 22V.

    hover.jpg
     
  2. Dave King

    Dave King Well-Known Member

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    I think that sounds about right Steve. The 4012's should put out about 1241 grams of thrust at 50% if you take away 15% loss of efficiency. Going by that assumption you would need to be around 21.8 pounds/9.9kg to idle around 50%. So either you are a little heavier than that or your efficiency loss is a little more than 15%.

    Don't forget to scale the BL's like Holger recommended. He's suggesting that you take a set of batteries off after a flight, fully charge them and see how much they charge. Then take the GPX data and see how far they are off. I had to run a number of 70 (from the factory 64 setting) on each BL to get my MAH GPX data correct.
     
  3. Tim Sessler

    Tim Sessler Active Member

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    Hm... that seems like a fairly short flight time, doesn't it? Definitely expected more from the KDE motors.

    With my current set-up - X8, T-motor 4012-09, Xoar 15x5 and dual 9000mAh 6S lipos - I am getting 6.5min at 24lbs.

    At the same time other people are claiming to get 20min flight time with U5 flat-8 (http://forum.mikrokopter.de/topic-45335-1.html) or even Chris from KDE mentioned they are getting 17min flight time with their 27lbs X8 running their KDE 4014 motor on 15” props.

    7.5 min seems pretty far from that, or?
     
  4. Steve Maller

    Steve Maller UAV Grief Counselor

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    Tim,
    I rarely want or need more than 8-10 minutes, and I never like to see my LEDs flashing or be scolded by Fraulein Graupner. I have a feeling I could push it quite a bit farther, and as Dave said above, I have a feeling my electronics could do with a calibration.

    As for the numbers others are getting, I’m well aware of that. But as somebody posted (don’t remember where I saw it), motor timing might factor in to that. Apparently lower numbers increase efficiency and higher numbers increase torque. KDE recommend a motor timing of 21° and MK recommends 28°. The current BLs only support 18, 24 and 28°. So I’ve lowered the timing to 24° and the copter seems to fly smoother. Not going to try 18° just yet (have a big gig coming up).

    It’s all very interesting. And confusing. o_O
     
  5. Tim Sessler

    Tim Sessler Active Member

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    Fair enough! :)

    I was planing on upgrading to the KDE 4014 and 18" props - your experience makes me wonder if 17" or even 16" might be the way to go. Really wish there would be a better way to determine what set-up will work best, without spending $$$$ and then realizing that it might have been not the best option... :-/
     
  6. Steve Maller

    Steve Maller UAV Grief Counselor

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    Tim, you hit the nail on the head. There are so many options that it’s enough to make your teeth hurt.
    It is not unlike the situation in the personal computer world where folks who want extreme performance take to building their own PCs using high-end parts that may or may not work together properly.
    The difference, of course, is when your 16-CPU 256-GPU 5,000 teraflop machine crashes, it’s not quite the same as when your Cinestar crashes. UAVs don’t recover with a Ctrl-Alt-Delete. :eek:

    BTW, I’m using the 4012 motors, not the 4014 motors. And to your point, I probably should have bought both, but you have to draw the line somewhere, right?
     
  7. Dave King

    Dave King Well-Known Member

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    Tim

    I'm the guy that made that claim. I contribute 4 things to the flight time.
    1. U series motors are the most efficient motors Tiger sells and the U5's I have are probably the most efficient out of the U line.
    2. I'm running the 10,000 QC batteries, I believe these batteries are a new line of lithium polymer batteries that have the highest energy density.
    3. My copter is very well balanced and its a flat 8.
    4. When I was running 19 plus minutes on a set of batteries, I was using a seperate battery to power my extreme mondo and LED lights. Since then I am now powering everything on the main batteries and I lost 2.5 minutes of flight time.

    At 6.5 minutes of flight time, I would question 2 things. How balanced is your copter and how good are your batteries. I would expect you to get close to 10 minutes of flight time at that weight with that setup. Are you using MK electronics with active breaking? I believe that the active breaking really helps flight time as well.

    ON my new X8 build I will be using 2 QC 16,000 batteries, and go back to a seperate battery to power the external stuff. I"m hoping for 16-17 minutes at 29 pounds.
     
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  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Mike...I must have overlooked something -- what's the Fortran-like formula. (And I'm impressed you admit to knowing Fortran! Ah, the GOTO.... :) )

    Andy.
     
  9. MIke Magee

    MIke Magee Active Member

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    Andy, Steve forwarded the following:

    I export the GPX file to a CSV in the grid view, then open it in Excel. I paste the following formula into the cell immediately to the right of the first cell in the RCSticks column (AN) and change the number format to Percent (no decimals). Don’t judge me for my ugly programming...I’ve clearly lost my chops in my 2nd life as a photographer. :oops:

    =(VALUE(MID(AM2,FIND(",",AM2,FIND(",",AM2,FIND(",",AM2)+2)+2)+1,FIND(",",AM2,FIND(",",AM2,FIND(",",AM2,FIND(",",AM2)+2)+2)+2)-FIND(",",AM2,FIND(",",AM2,FIND(",",AM2)+2)+2)-1))+127)/255

    And yes, did Fortran and it's illegitimate cousin PL/1 even. Those were the days.

     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Steve deserves a medal for getting that to work. Excel formulae are uggerrly.....

    I preferred RatFor: http://en.wikipedia.org/wiki/Ratfor -- you can avoid some GOTOs that way.

    Andy.
     
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  11. Devin Card

    Devin Card Member

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    Nice work steve!
     
  12. Steve Maller

    Steve Maller UAV Grief Counselor

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    Had the amazing opportunity to do some flying with a noted filmmaker in the Big Sur highlands today. What a thrill! Here are some nice photos that our companions shot of my copter in action.

    2014-05-06_08-18-34.jpg
    2014-05-06_08-10-25.jpg 2014-05-06_08-18-32.jpg 2014-05-06_08-18-34.jpg 2014-05-06_08-23-19.jpg 2014-05-06_08-36-35.jpg
     
  13. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Nice!

    And the bird behaved itself, I presume?

    Andy.
     
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  14. Steve Maller

    Steve Maller UAV Grief Counselor

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    Thankfully, yes. Those were some interesting winds coming up those hills! We’re going out at dawn again tomorrow to hopefully beat the breezes. The scenery here is positively breathtaking. Here is a still from the GH4 4K video...

    P1130016.jpg
     
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  15. Aj White

    Aj White Member

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    Awesome to hear! Seeing your footage is making me consider the GH4 again. Do you happen to notice any rolling shutter issues?
     
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  16. Steve Maller

    Steve Maller UAV Grief Counselor

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    no, but my sample size is very small
     
  17. MIke Magee

    MIke Magee Active Member

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    Nice work Steve. Congratulations. It must make all of that hard work building and tuning that X8 worth it. I'm glad it performed as you expected. I'm waiting for the nod from Transport Risk before I fly the M5 on the X8. I've got to get as pair of those sky colored headphones in the interim though. I'm sure they'll help.

     
  18. Marco Godles

    Marco Godles New Member

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    Hey guys! Ive been reading this thread with great interest!
    I just finished my Cinestar8 conversion to X8 and strapped my newly acquired M5 to it :D Happy Days!

    Here are some specs:
    Total Weight: 10kg
    FC: DJI Wookong
    Motors: Kopterworx KW8
    ESC's: Kopterworx KW60E
    Props: 14x7 Xoar
    Batteries: 2x 8000mah 5S

    Im running at about 90-100 Amps at hover. Just wanted to get an opinion is this a good average? Any suggestion on some improvements?
    Cheers!
     

    Attached Files:

  19. Jason Herring

    Jason Herring Member

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    Steve,
    How do the lights help? What's your flight times? And AUW? Thanks Steve for all your info,
     
  20. Steve Maller

    Steve Maller UAV Grief Counselor

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    And finally some video now that I’m back in the land of real internet. :)
    Read the description for more info about this clip.
    So very happy with how everything is performing!

     

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