Halfway through assembling and buying parts for my HL conversion and about to push the button on Motors and props but still undecided on few things and would really appreciate some thoughts. Currently: CS8 - upgraded Mikrokopter electronics, FlightCtrl V2.5, Quadro 2XL combi - cool Gimbal - FF 360 brushless conversion 180T's alexmoss Cameras: Mostly BMPCC - occasionally GH4 or 5DM3 Having looked at length through some of the HL conversions on the FF forum notably "Dave King" and "Steve Maller" (thank you both) I realise I'm targeting a slightly lighter overall weight than those carrying Red's but I know many of you also fly with similar payloads to this but have very different approaches... payload weight: Gimbal/camera/lens between 6.2 - 7.7 lbs current copter weight 450mm booms and QC-3328 motors -6.3 lbs I am aiming to keep to a single battery setup and looking at using 6s 16000's - approx 4.1 lbs So, realistically with new bigger motors I will be looking at about 19 - 22 lbs GAW Having seen the great results with both flat and X8 its hard to really work out from the evidence which way is best at this sort of weight and the use of a single battery setup - I'm swayed towards the flat setup for longer flight times with 500mm booms and 16" props but then whether to go U5's or KDE 4014 motors... I realise I'm being slightly vague but I wandered if because I'm lifting a slightly lower GAW than many of you whether there is any obvious ways to go given your experiences?
A couple thoughts for you...first, do you have any size limitations? A flat 8 with 500s or 550s gets pretty big. I'm not sure you can get 16 inch props on 500s. I think Dave cut down 550s a little bit for his 16 inch props. Advantage to the flat is full efficiency of all motor thrust - X8 loses some efficiency due to the stacked motors. X8 can have a smaller footprint and flies in the wind better. Also, if you decide to ever carry a larger payload, in an X8 set up you can increase the prop size due to having lots of room between motors. In a flat set up you would end up changing to larger booms first before you could increase prop size. X8 might be a little trickier to initially set up and dial in - probably not a big consideration. As for motors, U5s are pretty good. Some of us have had some issues with them due to their build quality. I had one have its screw rattle off that holds the motor bell on (top motor in an X8). Fortunately the motor bell did not fly away before the problem was discovered. Loc-tite should fix that. I have KDEs that I like (4014s). They also have some other new motors about to come out as well. With a larger motor like a KDE 4014, you leave yourself open to increase prop size. The U5s I think are only rated up to 16 inch. A lot of your answers will be determined by how heavy your total weight will be, if you want to leave yourself some headroom for carrying a larger camera at some point in the future, if you want the flexibility to fly dual batteries for longer flight times, etc. Having some extra headroom in an X8 is a very good idea to make sure you do not have yaw issues (especially in the wind) and account for the efficiency loss due to the stacked motor configuration. Good luck with your build...
My copter is AUW about 22 pounds with the GH4 on the MōVI M5 and dual 10000 Tattu or Pulse LiPos. I have KDE4012 motors and 16" Tigers. I tried larger props but they weren't a perfect match for these motors. But my hover throttle is about 52% and she is pulling about 65A at hover. So it's a good setup. And from a convenience and transportability standpoint, you can't beat a X8.
Dave I strongly recommend the 2 battery setup over one. Having used both copters a lot over the past couple months I can't say I like one or another over the other except the fact that I really like the extra battery time with the flat 8 setup. I know many people say that they don't need 16-18 minutes but its always good to land with reserve power. I tend to like flying the red with the flat 8 and the 5D with the X8 as I can still get 18 minutes flight time with the 5D using the X8. Good luck with your build.
Dave do you have any idea or does the gpx tell you how much the dynamic braking puts charge back in? I'm wondering how different flight times would be if running non MK with an otherwise similar setup?
Hard to tell because everythings different on this combination. I thought about deactivating active breaking and trying a flight to see.
Thanks for all your responses, after even more research overnight I think I'm there... The X8 evangelists have convinced me, I'm going for it... For me it will be mostly for practical reasons but I'm also looking forward flying a coax as so many of you seem to have good reports about the handling - I will go down the dual battery route (Point Taken Dave King) so am ordering some 10A Tattu's extra batt tray etc. I'm looking at the 4014's and like the idea of being able to scale up on the props in future as you suggested Micheal or perhaps just go big props straight away.... Is there any reason you went 4012/ 16" props Steve, the weight isn't that different and the prices are similar? I haven't studied the differences between Dave King's 4014/ 18" prop combo and your 4012 / 16" enough to see if there is any clear winnings but would be interested to know if you have any thoughts considering my payload will mostly be around 7lbs
Dave's flying a Scarlet on a heavier gimbal than me, so he needs the extra horsepower. My motors are very efficient at the AUW I'm flying.
Okay so I had a look back at your GAW is around 23lbs which is probably where I'm going to end up, that being proven and efficient I suppose the question is still for me whether there is any disadvantage to spinning bigger props and motors in order to have the extra headroom or does it actually become more inefficient to have the unused capability?
Dave I am almost tempted to change my 4014 X8 to a flat 8 so I could do a true comparison against the KDE 4014's and the Tiger U5's. I gotta say that I really like my U5 flat 8 combo. I am having some slight issues with the X8 combo including a drop or rise in altitude every so often. Not sure if its a flight control board issue or I need to spend some more time figuring it out but I really don't feel comfortable with it for jobs just yet. I just so busy that I haven't had the chance to really test it and give it the attention it needs. I also don't like the drop off in flight time with the x8 combo (about 4-5 minutes). It just doesn't seem right to have 2 huge batteries on it and only get 11-12 minute flight times.
Points taken and am now back to the normal levels of fantasy multirotor confusion I am used to... I feel a U-turn coming on Dave your suggestions are poignant particularly as I need my rig to be reliable ASAP, like next week - I actually don't have the time to really dial a completely new configuration in but it's something I want to be able to do or at least try in the near future. I'm in the UK and cant find sufficient stock of 4014's so I may actually just opt for a copycat of your flat 8 U5 16" combination (Dave King) as I think I can get that all delivered, assembled and tested in a few days - it's another case of knowing that whatever I buy it will be old news in a few weeks time, I think we are all used to that...
Yeesh, I don't have to tell you to be very careful with that. "A few days" is really perilous if you have a need for a reliable rig next week, as you say. And as far as being old news, that's a given. This stuff is all moving so fast! My approach is to dial in a reliable working config and stick with it. Then begin the planning process for the next one. Although I must say right now that the only thing I'm truly lusting for is electronics and sensors that can deliver better autonomy and "sense and avoid" capability. And that doesn't exist yet.
Hello Dave, For the Quadro 2XL-Cool ESC please check the SW version prior to integrating any of these large can motors. Here is the link to the upgrade process: http://www.mikrokopter.de/ucwiki/en/BL_V3Update We are currently running SW V1.04c on all our ESCs. Greetings, Adam
Steve, I should have pointed out that I've been running the new MK boards for a while now and had a few weeks with the Quadro 2XL-Cool with stock QC's3328's, 14" props and 4S 10A which has been working fine even if my flight times are very short comparatively (6 mins). So although I'm aware I need to update BlCtrl's (Thanks for the reminder Adam) I am thinking that the change of motors and props should be fairly simple unless I am missing something? I can always revert to my existing setup if things don't look solid
New version as of today: Version V1.06d since 30th June 2014 Redundance operation: some small bugfixes in communication some small changes in I2C-Data (not important for normal MK operation) Small cahnge in selftest procedure "ERR:Motor restart" at high current peaks the message "ERR:Motor Restart" could occure instead of "BL-Limitation" some motors lost commutation when driving at high currents then comes the message "BL-Limitation" or "ERR:Motor Restart" Timing 28° was improved for the case of commutation loss -> please try timing 28 if you have these effects
I completely agree. My X8 rig has over 50 flights now (2 months after the build) and I just used it for the first time on the job Saturday.
Thanks for your pointers and I do see that in reality this is going to take a lot longer than I had expected - still waiting for parts....