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

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

  1. Nick Wolcott

    Nick Wolcott Member

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    Thanks for the info Steve. Enjoy tuning.
     
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  2. Steve Maller

    Steve Maller UAV Grief Counselor

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    Here you go, amigo.
    View attachment 4213
     
  3. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Muchas gracias, Senior....

    Did you crank back the GPS gain on your MK board to 85% or leave it at the default?

    Andy.
     
  4. Steve Maller

    Steve Maller UAV Grief Counselor

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    And now the gimbal is working! Added the 3rd axis with a 8017 and cage from our friends to the east (the very far east), and cobbled together a handlebar from some CF tubes and a silicone kitchen mat. It weighs in at exactly 9 pounds (although I just realized that includes my SmallHD DP6 and ghetto handlebars!). EDIT: just removed the SmallHD and it's down to 7.75 lbs.

    I am pleasantly surprised that after some significant noodling around for about 15 minutes with the gimbal, the LiPo tester shows the battery still at 96% of capacity, so it could be that it'd run all day. :D

    So if I go with a smaller battery, remove, the monitor and bars, add my Iftron or Teradek Cube transmitters, I think I'll be at around 8 pounds with the GH3. Which is right about exactly where I was hoping I'd be. Now I'll strap a 10lb dumbbell weight on the copter and do some more flight testing!

     
  5. Steve Maller

    Steve Maller UAV Grief Counselor

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    I don't recall changing it. I'm running mostly defaults at this point. I've got the copter apart to change booms right now, so I'll let you know when I get it back together.
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Nice selfie. The dog was suitably laid back for a California dog... :)

    Andy.
     
  7. Steve Maller

    Steve Maller UAV Grief Counselor

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    More testing, this time with a 10 pound barbell weight. What do you think of my improvised landing gear? Worked great! Next step: try the Xoar or Tiger props. 11 minutes with this config and crappy props.

     
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  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    You need knife blades on the landing gear to make it look more threatening.... ;)
    It's making an interesting noise....very "laid back."

    Andy.
     
  9. Steve Maller

    Steve Maller UAV Grief Counselor

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    Everything looks better slowed down, and apparently sounds better, too.
     
  10. Steve Maller

    Steve Maller UAV Grief Counselor

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    OK, here is a GPX file with my flight data. If I did my calculations right, I’m right about 50% throttle or so on hover, which is outstanding for the load I’m carrying (a 10 pound barbell weight). This was a short flight with winds at 11mph and gusting to more. As you can see, current draws are pretty stable, and BL temps are super great, considering the fact that I was in a dead hover for a lot of the time. However, like I said, it was windy and ambient temp was about 55°F.

    MK Version: FC HW:2.5 SW:2.03d + NC HW:2.0 SW:2.03b

    Flight date: 2/15/2014 1:31:54 PM
    Flight time: 1:31:54 PM - 1:36:45 PM (291 secs, 00:04:51)
    Batt. time : 295 secs, 00:04:55

    Elevation(GPS) : 0 5.42 17.194 m (min/avg/max)
    Altitude(Barom.): -1.4 8.55 16.15 m
    Vertical speed : -1.44 -0.05 2.11 m/s
    Max speed : 18.3 km/h
    Max target dist.: 8.3 m

    Sats : 7 7 9

    Voltage : min. 21.4, max. 25 V
    Current : 0.5 68 101.3 A
    Wattage : 11 1535 2213.34 W
    Capacity: 5460 mAh

    Motor1: 0.0 8.4 15.5 A Temp: 16 19 25 °C
    Motor2: 0.0 9.2 15.7 A Temp: 16 22 27 °C
    Motor3: 0.0 9.4 14.6 A Temp: 17 21 26 °C
    Motor4: 0.0 7.0 15.7 A Temp: 16 21 26 °C
    Motor5: 0.0 8.1 13.1 A Temp: 16 20 24 °C
    Motor6: 0.0 8.1 14.4 A Temp: 13 18 22 °C
    Motor7: 0.0 7.5 14.4 A Temp: 16 19 22 °C
    Motor8: 0.0 8.3 17.9 A Temp: 14 20 26 °C

    Magnet Field: 101 110 117 % (ok)
    Magnet Inclination: 61 63 70 deg

    No errors found ;)
     

    Attached Files:

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  11. Dave King

    Dave King Well-Known Member

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    Steve your current numbers all look really good but your throttle is actually pretty high for hover. If you look at the RC stick inputs for the first 150 points before you go into altitude hold you will see that your hover gas is around 45-65. Remember the throttle stick value is the 4th number from the left in the RC stick column. I'm estimating its about an average of 55, add that to 127 you are around 182 hover gas which is 71%. As soon as you go into altitude hold you are releasing your throttle stick essentially and that's why you see the numbers very low (0-8). That's a false reading you have to look at where your stick inputs are when you have altitude hold off. I"m surprised to see the throttle numbers where they are for that weight with the 3515's but I think its the density altitude that's really helping you. IMO, go with the U5's with that kind of weight it should help improve the 5 minute flight time you were seeing even though you are not pulling a tremendous amount of power. At your DA I bet your current draw and power consumption would be cut at least 40%.
     
  12. Steve Maller

    Steve Maller UAV Grief Counselor

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    Dave, thank you for that, but I think you mis-read my info. My target flight time is 10-11 minutes. The five minute flight above was nowhere near max...just a test.

    Now, what I’m finding is interesting. First of all, my AUW is now 23.98 pounds with the 10 pound weight strapped to the copter. That’s considerably heavier than I originally targeted, so I think I have to do some better measurements. For one, my gimbal doesn’t weigh anywhere near that (more like 6-7 pounds, and the extra legs, silicone pad, and other things have maybe skewed things).

    I also finally worked up the courage to install my Tiger 15” props today, and the results are interesting. A 10-15% improvement in efficiency, based on hover current and battery consumption. So, with this test (a 10.5 minute flight at 24 lbs), I had no low battery warnings, and looks like about 1800 mAh less current consumed.

    But now I am wondering if I need to go up to larger motors and 16” props. While this configuration feels OK, what concerns me is what might happen if I lost a motor, or some other requirement for additional power. It feels like I am pushing the numbers a bit, but then again, maybe it’s ok. I wish I had a table of data like Tiger publishes for their motors so I could really go deep on the numbers.

    FYI, here are the two flights’ current numbers side-by-side. The left side is with the cheap 15” CF props, and the right side is authentic Tiger 15” props. I guess you get what you pay for. ;) I love real data.

    prop-comparison.jpg
     
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  13. Brad McGiveron

    Brad McGiveron Active Member

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    Love the gear Steve! Looks like a flying table :D
     
  14. Dave King

    Dave King Well-Known Member

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    HI Steve

    I didn't look at how much power you consumed 5460 mah I just saw max voltage at 25 and min at 21.4 and assumed it was a full discharge on the flight. What I like about the U5' is that they are dirt and water proof which is really good for you on the beach and they will give you considerable head room.
     
  15. Dave King

    Dave King Well-Known Member

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    Forgot to ask in last post if you were able to compare the throttle at hover between props?
     
  16. Steve Maller

    Steve Maller UAV Grief Counselor

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    Oddly enough, the throttle number looks higher for the Tiger props, which makes no sense, so I wonder if the formula is correct. After all, all other indicators show a 15% or more improvement.

    Are we sure the RC Sticks formula is correct? Or even relevant?
     
  17. Chris Fox

    Chris Fox Active Member

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    G'Day Steve,

    The question I want to know the answer to .... is how does changing props affect your satellite reception :rolleyes:
     
  18. Gary Haynes

    Gary Haynes Administrator
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    Steve the stick number is simply the position of the throttle stick. On a scale of 0-254 on the TX and in the MK -127 to +127. In the GPX viewer tool you can easily see the stick position while in manual mode. A value of 0 would be centered. Another way to check is to look at the stick position window on the TX. That will show the servo equivalent position of the stick.

    All that said if the value in the RC stick is 0 then you are centered. If it it +127 and the copter is descending....ouch....

    That said I looked at your GPX file in MK GPXtool and your hovering right at 69% (+50 stick) in manual mode.

    If you use the tool you will see in the Sticks/Potis windows a red and blue block. Red is your actual stick input and Blue is input that the FC in GPS is doing.

    Maybe Andy can look at the file. I see see strange dropouts, or at least what I think is strange. At 122 you are flying manually with the Free Fly and Man Ctrl flags on. But at 123 the Man Ctrl drops off for 2 seconds and then comes back on. I see this multiple times in your file.

    And I see a lot of Manual Control status flags on the GraphView Status Flag screens yet you are not in GPS Pos hold mode. Seem to remember you normally see that when you are in GPS PH and manually flying the sticks.
     
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  19. Steve Maller

    Steve Maller UAV Grief Counselor

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    Can I get it to go to 11?
     
  20. Steve Maller

    Steve Maller UAV Grief Counselor

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    Maiden gimbal voyage: complete! Footage to come. Very exciting (and terrifying!)
    VLC-snap001.jpg
     
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