Clockwise Yaw INOP. All ideas welcome.

Discussion in 'Cinestar 8' started by MIke Magee, Sep 14, 2013.

  1. MIke Magee

    MIke Magee Active Member

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    Well, today, I went through a thorough bench tighten and gimbal rebalance. Like dozens of times before.

    The test flight revealed that for some reason, clockwise yaw does not work at all. I've attached 2 gpx files. I'd suggest 13091410 for review. Please take a look. This was done on the bench downstairs w/o satellites, and 309145 basically demonstrates the same thing outside with sat fixes.

    In 13091410, you can see at about(all times approximate)
    :20 to :70 that counter clockwise sees the stick move and turns the copter - compass changes.
    :75 to 100 note full stick right/clockwise yaw, copter does not turn - even an inch, compass stays.
    :117 to :145 same as previous test.
    :145 to :160 hand rotated to demonstrate no binding on the gimbal
    :160 to end brief clockwise turn and then motors off.

    Does anyone have any idea how to address this? It's clear the sticks are sending the signal and centering when not. On the bench, props off, motor sounds appear audibly to inflect/deflect when the stick goes left/right.

    I'm totally open to suggestions on how to diagnose this and correct it. Lobster dinner in Boston and great appreciation to anyone who can unstump me on this one.

    Regards, Mike
     

    Attached Files:

  2. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Mike: In MK Tool can you verify what mixer you have set, please? Maybe even save and post the .mkp file?
    EDITHang on a second, are you using a two axis gimbal or a three axis? Disregard. The issue is not the gimbal -- at least I don't think it is.

    I looked at the GPX file and is shows what you says it does. The RC Sticks (and thus the Rx on the copter) appears to be receiving the Yaw Right.) Could this be a bizarre side effect of the GPS being off-line?

    Thanks
    Andy.
     
  3. MIke Magee

    MIke Magee Active Member

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    How are you Andy? 3 axis gimbal. Kinda hard to yaw on the ground with a 2.

    -m
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Doing fine, Mike, thanks.

    Oh....I thought you were flying when this was happening.... As you say, 2-axis doesn't work at all well for ground work.
    Have you got airborne and tried it? I thought you were hovering in ground effect but it must have just been an altitude offset.

    I'd still double check the Mixer setting and save the .mkp file if you could.

    Andy.
     
  5. MIke Magee

    MIke Magee Active Member

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    Andy, here's the .mkp. Also, here's a copy of the .mkp that I got in June after the FC upgrade by QC. The diff suggests that only the globalconfig3 parameter has changed.


    EDIT: oh yeah, it's octo2


    Don't know what globalconfig3 is but the code says:
    //Parameter.GlobalConfig3
    #define CFG3_NO_SDCARD_NO_START 0x01
    #define CFG3_DPH_MAX_RADIUS 0x02
    #define CFG3_VARIO_FAILSAFE 0x04
    #define CFG3_MOTOR_SWITCH_MODE 0x08
    #define CFG3_NO_GPSFIX_NO_START 0x10


    Anywho, I've got a hundred flights on this parameter set.
    But if anyone can point me in the right direction I know it's you.

    Thanks for any and all guidance.

    -m


     

    Attached Files:

  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Mike: The parameter sets are stored internally to the MK boards with versioning so that the code can recognize which set it is dealing with.
    Octo 2 is correct.
    Thanks for running the diff for me! (You're definitely a "Full Service Forum Member!")

    Do you happen to have a spare FC board you could try? I'm starting to wonder whether this might not be a hardware failure on the FC board.

    Oh....and you're entitled to one free anger at me for this question: Could you double check that all the props are on the correct motors, and all the motors are spinning the correct way? I'm grasping at straws here.... :) But that's what I'd check if this was my bird.

    Andy.
     
  7. MIke Magee

    MIke Magee Active Member

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    Thanks Andy. I was hoping you wouldn't use the "F" word (Flight Controller), cause that's what I was thinking, given the fact that counterclockwise yaw works OK as directed by the stick, and power and direction control are also OK.

    And, NO anger. The props are the first thing I checked, even though I didn't remove them. I will Quadruple check the props and motors. I don't have another FC. This one was replaced in the spring to eliminate excessive roll shudder, and possibly(not probably) when I had it upgraded in June with 2.1 upgrade.

    Hopefully someone else has a Mail Mary. I'll order a new FC (should have a backup anyway) Monday, but tomorrow's shoot goes down the toilet.

    Thanks for your very generous set of eyes Andy
    -m


     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Mike:
    Things to double/triple check:

    1. MK Tool shows that the yaw channel (Channel 4) is deflecting full up and down (corresponding to left and right). Given the GPX file, I doubt there's a problem here, but worth checking to save the shoot.

    2. Again, grasping at straws: Set the compass effect in the Misc window to 0 (it's normally 64).

    Nothing else comes to mind....I'll post again if I can think of anything.

    Andy.
     
  9. MIke Magee

    MIke Magee Active Member

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    Hi ANdy. Could you clarify? The compass effect options I have in Misc is poti selection.Poti's 1-8 are selectable.

    Am I looking in the correct place?

    Alas, the 5th check of the motors and props deem them correct.

    Tx,m




     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Mike:
    Yeah....I think you can either type a number or have it controlled by a POTI. I'm suggesting that you set it to zero.
    The compass effect controls the degree to which the magnetic compass is used for yaw control, and, as the problem you're having is in yaw, I just wanted to see if you disable it entirely, whether the problem would go away.

    Glad to hear that the props and motors have been eliminated..... :)

    Did you see full up/down deflection on Channel 4 in MK TOOL?

    Andy.
     
  11. MIke Magee

    MIke Magee Active Member

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    Andy, My default is currently set to zero.

    I did watch the sticks go full deflection in MKTools.

    I've submitted a support request to QC and will reference this thread and associated files.

    I've also just done this clip to demo the issue for them:

    Don't worry - the CS8 was tied down and only at about 10% power. I needed it running with the blades to repro.

    Thanks for your help - again, Andy.

    Regards, Mike

    p.s. PLEASE Everyone - Never - EVER - bench run a machine with the blades on even IF it's low power, and even if it's securely anchored.


     
  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Mike:
    Good demo video. That really illustrates the problem. I'm back to mentioning the F-word (as in Flight Controller).
    Given that you're seeing full deflection on Channel 4, then it would appear that FC is simply not driving the motors correctly.

    Have you tried "updating" the firmware to the FC with either 0.90j or 2.00? Again, I'm grasping at straws...

    Andy.
     
  13. MIke Magee

    MIke Magee Active Member

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    I like straws Andy. I'm at 90g. I really don't want to change too much at once at this point. Although what have your heard about 2.00. Doyou have it installed ?

    So I'll wait to speak with QC tomorrow.

    I've missed the shoot and decided to accept defeat for 12 hours and brood with a glass of Pinot.

    Regards,
    Mike


     
  14. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I tried 2.00 but there was some serious yaw-twitching I didn't like. I regressed back to 0.90j, but it still twitched -- it would be a sudden 22 degrees (approx) yaw right, followed by a gradual return to the original heading that took a couple of seconds. So I set the Compass Effect to 0 and it stopped doing it.

    Good "Missed Shoot" strategy, btw.

    Andy.
     
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  15. Casey Van Nyhuis

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    As Andy mentioned first on the list would be : props tight, props spinning correct direction (which i also did my best to confirm in the video), additionally ensure your motors are vertical. Jeff and I have both had instances where motors not being straight up have hampered yawing ability. There is also a chance that a motor is failing. Try offsetting all your booms and motors one motor position over and set them up so they are spinning the correct direction for their new location. (IE motor 1 in the motor 2 location, 2 in the 3 location 3 in the 4 location etc.) If you then have a problem yawing the opposite direction then you know it's a motor issue. If it's still having a problem yawing in the same direction you know it's either a brushless controller issue or a flight control issue. After trying this, put your motors back where they were and plug your motors into the brushless controllers but do it "offset" by one in the same way you did with the motors. By this logic if you do both tests you should be able to positively narrow it down to the flight control. It's early on a Monday and it was a long weekend for me so hopefully you can confirm that this logic makes sense Andy! ;)
     
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  16. MIke Magee

    MIke Magee Active Member

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    Thanks Casey. This should keep me busy for the afternoon. Thank goodness I have the "Casey drilled boom mod' that allows me to move them all around with the external connecters. Certainly this would be easier with a quad. I'll post the results.
    -m


     
  17. Scott Stemm

    Scott Stemm Member

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    Could you explain more on the Casey drilled boom mod?
     
  18. Casey Van Nyhuis

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    Basically you just drill some holes in your boom just before your booms enter your frame and route your motor wires out the side of the boom. This makes it so they don't have to zig zag back up through the frame under your dist. board. Shaves off lots of motor wire weight and makes it MUCH easier to assemble and disassemble to. BIG pain in the arse to do though. I'm sure Mike could post some pics at some point, ironically i havn't gotten around to doing it to my current kopter. Keep having to redo it cause Karsten keeps selling my kopters ;)
     
  19. Scott Stemm

    Scott Stemm Member

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    Tanks Casey. I have been trying to think of an easy way to be able to break it down and put back together again for both travel and storage. Sometimes the best solutions are the simple ones
     
  20. MIke Magee

    MIke Magee Active Member

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    Casey, I will tell you that this swap the boom exercise has MORE than paid for the mod. I've always loved the efficiency and practicality of your mod. Here is a shot. The wiring is a mess (pulled out of the booms a bit and messy in appearance) because of the process I'm in, but the picture shows the detail. The mod makes the wiring look good in general. Scott, you will like it of you do it. Also notice the rubber grommets Casey put in where the wires exit the boom.

    Casey, AFA the progress on my issue, After swapping the booms by one, the problem remains the same. tomorrow the booms go back to normal and i move the wiring. Should be done with it by the time you get in.

    caseywiring.JPG
     
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