Another guy just moved to dark side (MK to DJI)

Discussion in 'Electronics' started by Ozkan Erden, Jan 21, 2016.

  1. Ozkan Erden

    Ozkan Erden Distributor

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    I think I would be the last person on the planet who would move from MK to DJI, but, it happened.

    Now using two A2 based copters, I would like to thank Michael McVay, Dave King and Kate Nelhams-Wright for their great input and help.

    First decision was to move WKM with IMU v2 but I couldn't source it locally; so we evaluated A2 for a while and moved two heavy lift copters to DJI A2 based system.

    First copter:
    KDE 5215-435KV
    KDE 75A ESCs (These are very heavy duty ESCs)

    Second copter:
    KDE 5215-435KV
    Herkules III v3

    DJI and MK flies quite differently. DJI flies more straight, easier to keep it on the rail. More like a tank. For instance, ascending and descending speeds are limited by the software on DJI A2: 6m/s for ascending. With MK, when you give the full throttle, it rockets to the sky. With A2, no way for this.
    A2 holds the position better in wind, easier to configure. RTH works much easier. With MK you need to set tons of parameters.

    The telemetry is a serious issue. For now, I'm using iOSD MK II. With Herkules III, it's possible to get a better telemetry about battery, current and ESC temp. I need to get proper accessory for Herkules to make it work.

    I had tons of flight and I am very happy in terms of flight characteristics. I'm keeping my other MK copters, but they will be powered by Herkules III ESC.

    What did MK do wrong and I had to move to DJI as a FC system? I needed a better ESC. Even with Herkules III, in summer time, it's impossible to fly it with heavy payload. It gets very hot. And I don't have the courage to try PWM to I2C converters since I see them as a weak link in the chain.

    To fly a Alexa Mini with a hefty lens like Master Primes, + FIZ control, no way to fly them with regular MK based system safely in all conditions unless you build a X12 system with Herkules III.
     
  2. Michael McVay

    Michael McVay Active Member

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    Glad to hear you like your new set ups! Keep us posted on the A2 if you can. I have a new one sitting in the box that I have never opened based on all the early issues it had when it first came out. Also have a Herk III on an MK rig - if you have good luck with the Herk III and A2 maybe I will give it a try on a test rig.

    Thanks for the update!

    Michael
     
  3. Howard Dapp

    Howard Dapp Active Member

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    Good luck Ozkan! My MK setup is similar to your old setup: KDE 5215-435 w/75a KDE controllers, KDE 4014-380 w/KDE 55a controllers. I've been using an Afro PWM to 12 converter with both rigs for over a year now without any issues (knock on wood). Let us know your thoughts for wind performance between both flt controllers.
     
  4. Ozkan Erden

    Ozkan Erden Distributor

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    Michael, to be honest I can't see any difference between Herkules III and KDE ESCs in terms of response and flight characteristics. I personally find Herkules III quite reliable as long as the AUW doesn't exceed 15-16 kgs.


    Thank you Howard. Maybe I need to give a chance to Afro I2C converter on a test copter.

    As for the wind performance, as long as both copters are in Altitude Hold mode, both reacts similar. Both floats with the wind as long as the gains are dialed in. I flew A2 in 15-20 knots of wind, and I didn't say "I wish I had MK copter with me". It performed good.

    When GPS is activated, actually MK is performing worse in windy conditions. No difference in non-windy conditions. MK has speed problem in GPS mode; you need to adjust Stick values to make the copter faster along with the GPS values, but it also makes the control more sensitive to stick input which is not good for filming.

    A2 is more sensitive to gain settings. Especially the IMU/GPS positions should be adjusted accordingly. With MK, I could fly any type of copter without changing any PID settings.

    So far, MK is better in terms of (my humble opinion):

    * Vertical agility
    * Telemetry (The gap between A2 and MK can be filled in with Herkules IIIs telemetry solution)
    * Data logging (which helps while inspecting issues with the copter)

    Will update this topic as much as I can.
     
  5. Dave King

    Dave King Well-Known Member

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    Congrats, welcome to the dark side. I think MK's limitations were stretched to what they could do with a 3-4 person operation.
     
  6. Howard Dapp

    Howard Dapp Active Member

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    Ozkan, is your DJI setup coaxial? I know your mk rigs were coax, how does AH perform on a loaded setup compared to MK?
     
  7. Ozkan Erden

    Ozkan Erden Distributor

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    Howard, they are both coaxial. A2 also looses altitude when flying forward and backwards as MK does. A2's AH performance is tiny bit better but not a huge difference.

    AH is always on with A2, so that makes the copter easier to control. MK used to bounce when you try to land when AH is on. So I never had the courage to land MK when AH is on for years :)
     
  8. Ozkan Erden

    Ozkan Erden Distributor

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    Just a note to the guys who are planning to use Graupner radios on A2.

    A2 accepts PPM, thus it's possible to use Graupner radios. But over PPM, only 8 channels are supported. So, if you don't adjust your RX settings SUMO to 8 channels, the radio doesn't work properly. Weirdly, the channel 7 triggers FailSafe with Graupner if the SUMO is higher than 8 channels. (Even on RC channel settings in the app, you can't see any channel moving when you move switch which is on channel 7, but somehow it puts the system to FS).
     
  9. Thijm le Grand

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  10. Michael comissiong

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    Hi
    I find that strange that DJI A2 ppm only 8 ch work , are you positive ?,as I have a DJI wkm system that gives me 12 ppm ch with my MX20 radio , and was thinking of upgrade to A2 .
    I Will have to re look that if that is so.

    Thanks
     
  11. Ozkan Erden

    Ozkan Erden Distributor

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    A little update:

    It has been almost a year A2 has been serving us perfectly with KDE 75A ESCs and KDE 5215XF-435KV motors.

    I still had MK Octocopters which I was holding them as a backup and now moving them to A2 too. On MK copters, I'm using KDE 4014XF-380KV motors. I had extra KDE 75A ESCs (with the latest firmware on them ), they are a bit heavy over-amped for a 4014 motor but in theory they had to work.

    But, I had huge problems with KDE 4014-380KV motors and KDE 75A ESCs. The motors are cogging and causing instability in flight such as uncontrolled yaw. I tried Herkules III and it is working flawlessly. Another ESC working beautifully with these motors and A2 is the Hobbywing Xrotor Pro 40A ESCs. The price for one ESC is around 20$ and it is handling the system pretty well. AUW is around 14kg.

    So, now trying A3 Pro on an X8 system but I think A3 Pro is not %100 usable without LB2. And LB2 means, lots of new investment, and limitation on the gimbal choice as it blocks the 2.4 frequency band.

    So, for us, A2 is still the choice for big productions.
     
  12. Michael McVay

    Michael McVay Active Member

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    Thanks for the update. I am currently trying an A3 and a LB 2 on a test copter. I decided to do this following the purchase of an M600 and being extremely impressed with its results. At the time I was flying a WKM Cinestar 8 and an Alta 6. Now, my M600 has become my go to rig...it holds altitude better than anything I have ever flown. I have not tested an A3 on an X8 yet, but the A3 has gone with the counter rotating motor pattern (like MK) so no need for the custom mixer. And if it holds altitude as good as the M600 does it might be the solution everyone has been looking for on the heavy lift X8. I'll be very curious to hear how it works for you Ozkan. And if you need anything for testing let me know. We are now a dealer for all DJI products and have all the new stuff - happy to take special care of any fellow Freefly members who need anything. www.FloridaDroneSupply.com
     
  13. Jason Herring

    Jason Herring Member

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    Can't wait to see how the A3 works with a heavy lift x8
     
  14. Ozkan Erden

    Ozkan Erden Distributor

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    Trying A3 on a heavy lift X8 with Futaba remote but so far there are several major issues which beholds me to use this controller:

    • Motor disarming feature is not same as A2 and it's very dangerous at the moment. Once the A3 is armed, it will not disarm before you bring up the throttle to 30% or more.
    • I couldn't put the copter to compass calibration mode with GPS stick moves (A3 Pro). It has to be done via computer USB cable.
    • Software is buggy still. IOC menu doesn't appear on the desktop application.
    • With the latest firmware, the calibration of the RX and channel mapping was lost a few times by the app. So I had to do everything from the beginning.
    • Several times, I had GPS connection error while configuring the system. I had to reboot the system in order to make all 3 GPS to work. The plugs aren't as as securely locked as A2 GPS plugs. Users should be careful about this too.
    • Not possible to use Graupner PPM receivers. On our A2 systems, we were using our Graupner systems without any extra cable mess.
    • A3 LED is not visible in daylight even from 1 meter distance.

    Apart from the software issues, to be able to use A3 with regular radios:

    * It should be possible to calibrate A3 Pro compasses without a computer.
    * Same LED as A2 should be provided(maybe a bluetooth integrated one so we can also access wirelessly through IOS).

    So overall, for me A3 is not reliable at the moment. But if I decide to move a LB2 route, then things can change.
     
  15. Howard Dapp

    Howard Dapp Active Member

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    Ozkan, thanks for the update. Are you running the 5215-435 & KDE 75A ESCs with the default FW settings?

    - SYNCHRONOUS RECTIFICATION (ACTIVE-FREEWHEELING) - ENABLED
    -S.R. BRAKING ACTIVATION (REGENERATIVE-BRAKING) - DYNAMIC

    confirming would be very helpful.

    Thanks!
     
  16. Michael McVay

    Michael McVay Active Member

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    I am trying one (regular A3 - not pro) with a LB2 and so far so good (functionally). I am going to try adding a DJI focus to it as well and see how that works. Obviously using the LB2 radio, I can have an iPhone for the app to get A3 control (calibration, etc) and use the SDI or HDMI for a decent monitor. I'll post back with anything interesting I experience.
     
  17. Ozkan Erden

    Ozkan Erden Distributor

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    Hello Howard,

    All settings are stock, no changes.

    You are right Michael, with LB2, it adds lots of ease in usage. But, I'm using Movi and Movi controller, which is using 2.4 GHz as well, making LB2 not usable in this configuration.

    So, LB2 means that I have to move all my ecosystem to DJI products and I simply can't do that. We have 6 heavy lift copters, 6 Movi gimbals and they are all interchangable with each other. So I can't migrate to a complete DJI ecosystem in budget wise and compatibility wise. One example, DJI Focus is great but we mostly fly with 2 motors, and with 3 motors on some occasion.

    So for me, evaluation of A3 should be based on regular radio integration.
     
  18. Michael McVay

    Michael McVay Active Member

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    I totally understand. I am curious why it is giving you so much trouble...unless they just changed the design all together. if I get a chance soon I will also try an A3 with a different radio on a CS8 and see how that goes. Most of our Cinestars (all but one) have WKM on them.
     

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