Best flight controller for heavy lift systems

Discussion in 'MōVI MR' started by JASPER GLAVANICS, Aug 12, 2015.

  1. JASPER GLAVANICS

    Joined:
    Nov 5, 2013
    Messages:
    97
    Likes Received:
    1
    Hi all,

    Thought id post another thread on flight controllers. s
    What is the general consensus of what flight controller to use for heavy lift systems. Would people prefer DJI A2 over the Mikrocopter systems, or DJI wookong etc.

    I am running a custom X8 configuration of a cinestar frame, with dual redundancy Mikrocopter flight controller. However when in GPS it just doesnt seem to like the heavy load at all. Also when not in GPS, there is relatively no stabilisation, so one has to concentrate 100% of the time on focusing on the drone. Even if i take my eye off it for a second in manual mode, it will have either gained altitude, descended or drifted off on its way to the next suburb.
    My setup is lifting a Red Dragon with a Movi M15. 8 x U7 motors and a small frame footprint give the machine some serious lift capabilities. In total prob around 15kg.

    Keen to either see others systems or thoughts on the best flight controller for this type of drone.
     
  2. Steve Maller

    Steve Maller UAV Grief Counselor

    Joined:
    Oct 30, 2012
    Messages:
    3,979
    Likes Received:
    807
    Mikrokopter flight control systems are not very useful with default settings. It sounds like yours may need some serious tuning. If it's very unstable in "manual" mode (which isn't really fully manual) and doesn't hold in GPS mode, something is wrong. And what is your center of gravity like (vertically)?

    And be careful if you're using the MK BLs. That system may be too heavy for the BL 3.0s, and AFAIK there were some issues with the U7 motors, as well.

    The truth is none of these systems is "plug and play". They all need some degree of tuning. Some more than others.
     
    MIke Magee likes this.
  3. JASPER GLAVANICS

    Joined:
    Nov 5, 2013
    Messages:
    97
    Likes Received:
    1

    Hi Steve, thanks for your reply.

    Would you say that DJI systems such as the A2 are more reliable than MK? In regards to a heavy lift machine ..
     
  4. Dave King

    Dave King Well-Known Member

    Joined:
    Dec 24, 2012
    Messages:
    2,711
    Likes Received:
    311
    I have plenty of experience and feedback to share. I have flown MK for 3 years in all sorts of configurations from mid lifters, to heavy lifters to flat 8, to X8. I have at least 3000 logged flights on MK electronics. Last fall I had a few safety concerns regarding the I2C bus on the dual quadro board. Last year I ran the dual 2X quadro boards all year and had 5 of them fail. The last straw was in the fall when the MK went out of control after it launched because the I2C bus failed. Up until this past winter I was too scared to use DJI. So over the winter I built 2 new rigs. After talking to Michael McVay in length, he convinced me to try it and built a Wookong rig using 5.2 software. He was convinced it was a reliable flyer using that firmware. I also simultaneously built a new MK rig with redundancy and a backup I2C bus. The DJI Wookong is hands down the Wookong is a better performer and more reliable. I have flown the Wookong all year long as its been my number one flyer. I have at least 600 flights on it if not more and it hasn't hi-cupped once. It flies better, it tracks better, it hovers better.It hovers extremely tight to the point that I can get real close to a tree if I have a tight shot I need to get. I can't do that with the MK rig. For consumer grade GPS the Wookong is the best you are going to get from a heavy lifter.

    I feel the Wookong is more reliable because I have not had one GPS hi-cup or glitch despite the heavy useage in all sorts of conditions and locations. I've used it in Cleveland, Akron, Pittsburgh, and NJ. With MK I will get occassional GPS glitches where I have to very quickly deactivate GPS because it freaks out and the copter does something unpredictable. IMO the MK GPS is much more susceptible to signal noise and environment. If I was an inexperienced pilot I would have crashed a few times. I have had this issue on all 4 MK rigs I have built since I started flying.

    The only thing I wish the Wookong had was telemetry back to the radio. Telemetry is limited as to what you can get in flight and you are at the mercy of the OSD-downlink signal to get a signal. NO way to get the LED lights to blink and trigger when you get low battery levels.

    Two weeks ago I had to do some maintenance on the Wookong to replace a couple KDE motors that had a bit of excessive movement of the bell up and down. So I had to use the MK rig for a video job that required a lot of tight precise movements and I was saying over and over again I wish I had the Wookong rig. Got my Wookong rig back up last weekend and immediately noticed the flying difference.

    The new MK rig with redundancy features works well when tested. I have the ability to simulate a I2C and FCB failure and it has switched over to the backup FCB as designed.

    Here's my current setups.
    Cinestar flat 8
    Wookong on 5.2 firmware
    Upgraded IMU (V2 silver one)
    KDE ESC's and 4012 motors.

    Cinestar flat 8
    MK dual Quadro XL board with redundancy features.
    Backup flight control board
    Tiger 4120 motors

    I tried the MK in X8 configuration and could not get the altitude to hold tight while moving forward slowly.

    As far as tuning goes the Wookong needs its basic parameters setup by using a knob on your radio where you play with each adjustment to get the best response. Out of the gate in stock settings it was still better than MK. The Wookong also does not fly well in wind if you use stock settings and you need to move the CG numbers much lower than its actual measurements. Not sure why this happens but I had to experiment with it a bit to get it to where I needed it.

    Fail safe mode comparisons
    I have had the chance to use and compare the fail safe features on both setups. By far the Wookong is better. The Wookong will return to home and land very very slowly in the exact spot I started it within a few feet. The MK rig will come home properly but I have yet to have a successful emergency landing as it descends way too fast for my comfort level. I have had to abort every attempt because it's dropping faster than I feel it can land safely without damage. One time I was bold enough to let it go until about 40 feet from the ground and then switched it on. It powered back on just in time before it hit the ground. I have tried just about every setting with emergency gas as directed by Holger to no avail. IMO MK thinks it has something to do with heavier loads and MK is not taking payload into consideration with its algorithms.

    Heavy Load comparisons
    With the Wookong you have your choice to use every heavy lift motor out there and can run heavier payloads if needed. With MK you are limited to the Tiger 4120 motors and payload is about 27 pounds max. The MK board can only handle about 300 peak amps and a 240 continuous load safely. They are not the 40 amp rated ESC that they claim they are.

    Way point flying
    This is the only area that MK has the advantage if you plan on doing way point flying. DJI can only do it in later firmwares that are not reliable. MK does it pretty well and I have pretty much dedicated the MK rig to my survey and mapping jobs.

    I would never ever try to use the A2. Too many horror stories even in regards to the latest improved software. I wouldn't even try it if you gave me a free copter and A2 as I fear that it can spin out of control and be unsafe at any given time.


    Hope this helps.


    Dave
     
  5. Gary McCready

    Gary McCready Active Member

    Joined:
    Oct 26, 2012
    Messages:
    284
    Likes Received:
    42
    Dave: That was very helpful, thanks.
    I have a DJI S900, with an A2, flying with my Graupner (MX-20 & MZ-24) and use the HOTT Air Module 2s-14s, which can send telemetry for voltage up to 14s or two 7S batteries. It does have a 150A continuous, 300A max, is kinda large, and is a bit of a pain to setup, but it is great for keeping track of my voltage, and produces warnings.
    http://www.openhobby.com/front/productdetail.php?productcode=001000000000000904&sort=
    Manual: (english)
    http://www.graupner.de/mediaroot/files/33620_ELECTRIC_AIR_MODUL_WEB_V1.3_EN.pdf
     
  6. Angus Benson-Blair

    Angus Benson-Blair Active Member

    Joined:
    Jan 23, 2013
    Messages:
    147
    Likes Received:
    25
    Just a quick one on the A2- it flies better than the Wookong and offers more. Is it reliable though? At first it was terrible- a bit like the Wookong was. Now it is rock solid and every bit as reliable as the Wookong.
     
  7. JASPER GLAVANICS

    Joined:
    Nov 5, 2013
    Messages:
    97
    Likes Received:
    1
    Thanks Dave for that detailed run down. Really helped.
    I personally have never liked the MK product, as the interface on the computer app if I needed to change something was extremely difficult to understand, and I would have to get the manufacturer of my custom drone to alter anything if needed. I do like the telemetry however and also the dual redundancy thing is a piece of mind.
    After many test flights with my heavy lift and the MK, and comparing it to my smaller systems with the A2, I would go A2 any day.
    However my past experience with the Wookong is not great. I had the very first wookong that came with the S800 and it failed a number of times. I lost a machine into the ocean thanks to its malfunction and the classic flip upside down and crash thing. What made it worse was that DJI never claimed any responsibility for it.
    Anyway, I hear a lot of good things about the Wookong these days.. so am curious to know if it really would be better to use than the A2.
    Does anyone know what controller is in the Inspire 1? As this is currently my favourite machine and am totally comfortable for the first time. lol
    I have put the word out to a colleague of mine from another top drone company here in Oz, they are running the same payloads as me. So will be interesting to hear what they use.
    Anyone out there running a larger X8 system with the RED Dragon, CinePrimes, M15 and Tomahawk? Around 12 - 15kg total takeoff weight including copter and batteries ..
     
  8. Dave King

    Dave King Well-Known Member

    Joined:
    Dec 24, 2012
    Messages:
    2,711
    Likes Received:
    311
    Hi Jasper

    My pleasure I heard rumors that one of the issues with some Wookong controllers were bad solder joints. Before i ever used mine I took the cover off and touched up all the solder joints just to be safe. I also heard rumors that the older IMU's were problematic. I essentially copied Michael McVay's setup with the V2 IMU and both of us have been problem free with over 1000 flights combined on our setups.

    AS for the Inspire 1 its a custom controller designed just for the inspire 1. I have heard they are tight lipped about it and don't give out any info on it. I have the Inspire 1 too and have used it on probably over 200 flights this year and its a work horse. I use it for indoor stuff a lot and for realtor jobs where the sellers just want a few aerials nothing fancy for the web.
     
    JASPER GLAVANICS likes this.
  9. Dave King

    Dave King Well-Known Member

    Joined:
    Dec 24, 2012
    Messages:
    2,711
    Likes Received:
    311
    I have read about several flyaways and or crashes from A2 using the latest most up to date firmware on the Multirotor forum. o_O Forget giving it to me for free, you couldn't pay me to use it any where near people, cars, or buildings. I would have to make at least a few hundred flights on a large farm before I had even the "smallest" confidence that it was safe. Then again who has time to test a rig a few hundred times before you can use it in real life. :eek:
     
  10. Dave King

    Dave King Well-Known Member

    Joined:
    Dec 24, 2012
    Messages:
    2,711
    Likes Received:
    311
    Sounds good Gary. I'm using Spektrum for the Wookong though. I only use Graupner for MK. Did you ever get fail safe to work?
     
  11. Gary McCready

    Gary McCready Active Member

    Joined:
    Oct 26, 2012
    Messages:
    284
    Likes Received:
    42
    Dave: the only time FS didn't work was about a year ago, when the Receiver had an update, but MK told me how to fix that. However, I've not had the cajones to actually turn off my Tx, I just tested it in MKTools, and RTH works fine. Haven't really been flying much either, my health has been marginal for the past year, but I'm finally get back on track.
     
  12. Ozkan Erden

    Ozkan Erden Distributor

    Joined:
    Aug 3, 2012
    Messages:
    678
    Likes Received:
    131
    Dave, thanks for the great input. Your post is one of the most useful comparison ever written.

    I echo the problems of mk bl controllers, i also had over 6 different bl problems. Gps problems also exists with me. The ribbon cables can get loose, the controllers are not in enclousure etc.

    MK has real 12 motors support, so I am moving my octo configs to x12 setup to have heavy lift setup with kde 4014 motors. That's how I am going to use my existing MK systems.
     
  13. Dave King

    Dave King Well-Known Member

    Joined:
    Dec 24, 2012
    Messages:
    2,711
    Likes Received:
    311
    HI Gary

    Sorry let me rephrase, FS works with MK for loss of radio signal, however emergency landing descends way too fast and I believe that the copter/gimbal would get damaged. Emergency landing worked every time I tested it, but it just descends too fast for what I believe would land safety intact. Like I mentioned I have not had the guts to let it completely fall all the way down because as I watch it descend it just descends to fast for me to believe that it will slow down enough. I have been told that it will start descending slower as it gets closer to the ground but I certainly am not going to risk my stuff just to find out. I set my CH altitude to 50 meters and have watched it fall from 50 meters to about 15 meters it was at 15 meters where it was just falling way too fast for me to continue the test and I turned the radio on. Once I turned my radio on it just barely turned on in time for me to control put the brakes on it as it was about a feet from the ground. There's no doubt that if I kept the radio off it would have crashed into the ground. I did about 5 tests over a period of several weeks like this going back and adjusting the emergency landing/gas settings to no improvement so I gave up on it hoping it just never comes to that point.

    Sorry to hear about your health and glad to hear your getting back on track.
     
  14. Dave King

    Dave King Well-Known Member

    Joined:
    Dec 24, 2012
    Messages:
    2,711
    Likes Received:
    311
    Thanks for the comments Ozkan. Wow that's a drastic move going to a X12 what are you going to do about the altitude problems with X8 and MK? Switch to Wookong or Alta IMO.
     
  15. JASPER GLAVANICS

    Joined:
    Nov 5, 2013
    Messages:
    97
    Likes Received:
    1

    When I had to do my flight test for the Operators Certificate here in Australia, I had to switch off my heavy lifter and test the FS. Unfortunately it didnt work as planned and was way off the mark of takeoff, it then proceeded to descend and at around 3 metres it just dropped to the ground. Luckily the ground was quite soft after rain and it hit and then bounced, at which point i turned the radio back on and took over again. Not enjoyable. lol Got a great video of it... i should post sometime.

    Also when testing the other day. Whilst in manual mode at a range of about 150metres, it suddenly banked back toward home point and started coming back. So not sure what happened there, but it would have seemed to have gone into return home mode, without any input from controller... bizarre.
    Hence why i have not that much faith and trust in the MK systems. Just like the first gen of Wookong. In fact the only system i have had faith in is the Inspire... whatever it holds under the hood. ;)
     
  16. Gary McCready

    Gary McCready Active Member

    Joined:
    Oct 26, 2012
    Messages:
    284
    Likes Received:
    42
    Thanks for the clarification Dave. I ran across this awhile back, and wonder if it "fixed" the speed problem. I've never tried to let my MK boards land my copter. I just get it in close enough to see well, and get it oriented, then take over.
    4-22-15
    "Updates

    NaviControl V2.10b
    - Bug fix: speed for Coming Home was too high and did not correspond to the setting on the SD card
    - In the case of fail-safe (low voltage or signal loss) is to approaching the failsafe position always with 10m / sec (36km / h) flown

    https://translate.googleusercontent...ALkJrhhAuCo897-C3XxcaW02JE-OCEdX8A#post538209
     
  17. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,351
    Likes Received:
    1,160
    Gary: I think the 2.10b update corrects horizontal translational speed, not vertical descent speed. But I could be wrong.

    Andy.
     
  18. Ozkan Erden

    Ozkan Erden Distributor

    Joined:
    Aug 3, 2012
    Messages:
    678
    Likes Received:
    131

    I already have the AH problem with X8 but I compensate it with sticks.

    For Alta, I decided to wait a bit. I need redundancy in case of failure and it looks like the thrust of the system is not enough to compensate the failure.

    I will migrate my MK 2.5 + Herkules III + KDE 5215 system to Wookong M. We will see how it goes. It will be finished at the end of September.

    Thanks for the comments again.
     

Share This Page