DJI A2 FC?

Thanks again ;-)

So to resume, if I understand correctly what you say. I've sold my power to the exit on your picture. Then I've plug everything as usual except the red wire between the ff mother control and the ESC's modules? And I won't need any ESC between the FF motor control board and the PMU of DJI?

Thanks for the confirmation, I try this configuration this weekend ;-)

 

I might have misspoke this you can have all three wires on the Futaba style connector. They must have changed because this because people were probably changed this because were damaging their WKM's.

Here is the sequence.

1. Main power from the solder pads on the FF power distribution board in the picture will connect to the PMU.
2. The 2 male power connectors with the 3mm bullet connectors all do plug into the respective ports on the FF PDB.
3. The three prong signal wire on the ESC (I believe futaba style RC connector) will connect to the A2 Main Controller.

Here is a picture of a similar setup except is a Wookong M instaed an A2 but the principle should be the same.
Obviously the Deans will be gone and this will be hard soldered onto the board wthi just the yellow XP60 bullet connector.
This is notionally what it will look like except instead of a wkm its an A2.

I hope that helps I did not want to stray you the wrong path. I might have mispoke it looks like you can all three wires from futaba connector by looking at the diagram. This must be something they changed. Here is the weird thing is that they don't explain in the A2 manual that you do not need the power wire from the ESC, but it should not be necessary, since this is only providing the pulse width that governs the speed of the motors.

Shaun

 

You might want to test this the middle wire first and make sure it is not going above 5V. I would assume that this futaba plug is a BEC but there is not documentation stating so. It would suck if it is providing higher Voltage. In theory you dont need the middle wire because the A2 should all ready be getting power from the PMU.

 

Thanks a lot Shaun. You help me a lot. I keep you some news with our first fly ;-)

Take care.

Loïc

 

What is the best to carry a sony FS700? 6V? And how to reprogrammed it?

 

I am not sure I follow your question. Are you talking about powering the FS700 off of the Aircraft Lipo through thee FF board? If so I would say no, don't do that. Besides unless you know something I am not aware the FS700 takes 8.4V/7.2V battery, coincidentally a 2S LiPo. If you did not want to use the stock 6600 Mah camera battery you could use a smaller 2S Lipo if weight is concern.

Couple reasons why I dont think its a good idea. One is that you probably will get noise introduced video by using power off of the aircraft. Two, I am in the mindset that the main power supply to the aircraft should be dedicated to the aircraft, you do not want more things sucking power off the battery than necessary.

Just for curiosity what motors and props do you plan on using? This is important to know.

 

To answer your question you would plug in the ESC to the programming card with the all three connectors in tact. It looks like you have two readouts one is the item number than the other is its corresponding value. By looking at this looks like you press the item button until the number 10 is displayed in the left window. Then I assume you would press the value button to cycle through the corresponding values that represent the setting you want in the right window. Which in this case you would select number (2) for 6V.

Be real careful in what you are doing so you don't inadvertently change one of the settings on the ESC like the PWM frequency or the brake. If one esc has a different setting than the others could lead to undesirable effects.

Shaun

 

On another note.

I am not sure how much time you have in flying these things. But I would say be very careful and follow the manual to the letter. Understand the following.

1. Memorize the LED patterns so you know which flight mode you are in and especially the warning patterns or indications such as, Low Battery and Loss of GPS signal. I am still trying to memorize these my self

2. Understand the different flight modes like Atti, GPS Atti and Manual. ***Manual will not allow the copter to self level and should be disabled in software. This is only for sport flying, like doing loops etc.***

3. I personall,y would not fly that FS700 until you are very competent in the flight characteristics of this copter. I would fly an equivalent weight ballast first. Bringing it out of high altitudes is probably one the most dangerous tasks to accomplish safely especially when carrying heavy weight cameras. Dropping it too fast will cause a descent rate that might be unrecoverable even if full throttle is applied and lead to a crash Also the footage looks like garbage because the copter is flying through its choppy air.

4. Learn how the fail safes work, this is important when you lose radio control with the aircraft.

5. Know without any question how Intelligent Orientation Control or IOC works. These functions are synonymous with what is known as Carefree to all of the Mikrokopter people. IOC is responsible for loss of orientation and commanded flyaway leading to a crash in a lot of cases. There are two IOC modes, Course Lock and Home lock. Home-lock orients the pitch stick to your launch location know and no matter what direction the front boom is pointing, and no matter what point in the sky the copter is at compared to you r location. Course Lock is not so nice it remembers the course the front boom was oriented to at engagement.

6. Get I-OSD for DJI. This will let you monitor all your flight parameters and battery voltage on a video screen via video transmitter. If you have a 3 axis gimbal you will want to install a nose camera.

7. If you haven't done so, get a flight simulator. Aerosim RC has a Cinestar 8 standard setup modeled with MK. The flight characteristics wont be exact especially if you are using a 6S setup but it will be pretty good start of what to expect. It probably will be similar to a 6S with heavy camera and lens like your FS700 and a 18-200 barrel or more like a RED. Once I get my heavy lifter built I plan on making different models with different simulated camera setups.



Anyway just some helpful advice.

Shaun

 

hi Shaun,

First, I dont want to power my FS700 with the lipo. That's crazy ;-)

I just ask why to put the motor to 6V? Give it them more power?

I don't know what kind of motor I have on my cinestar. They came with the quadrocopter kit and it's wrtie on it quadrocopter.

I already flying the cinestar with the mk board on it. Most of the time I flew in manual mode with a canon 5D on it. I've change the system now for the dji. And before I never did RC. That's why I don't have all the knowledge ;-)

I bought also the I-OSD. What is a a nose camera? Is it a small camera for only the pilot? If it's the case, I've already have one ;-)

Thanks again, hope to have soon some amazing footage ;-) I've just have to wait on a wire to soldering ;-)

 

Oh ok I see what your asking, no that BEC has nothing to do with to do with your motor voltage. It is just supplied a][for convenience for Flight Controllers that do not have a power management unit or way of getting power from the battery without having to buy an external BEC. Your motors see what ever voltage your main battery is delivering. So with a 4S battery your motors get 16.8/14.8 volts minus the sag as you pull more current. 6S gives 24V respectively. It does not matter what voltage you set that BEC to for your motors. Its low range is 5.3 for FC's that do not have an internal VR and need a reference voltage of 5V for logic high. 6 Is for Flight controllers that have a VR that steps down to 5V. DJI A2 is already being powered by the PMU which is why that voltage is not necessary and is redundant.

If you are going to use the A2 with 6S batteries you will not be able to really get much out of the Stock QC 3328 motors. If you are using stock motors you will need to stock with 4S batteries. 6S batteries make the stock motors real hot from my research. Ideally you will need a setup that can handle larger motors and longer props. Either you will need 500 or 550 booms to accommodate 15 to 16 inch props or you will need to do a Coaxial setup on the current booms where you have a quadcopter looking aircraft but each boom has two motors. This is the setup I am going to try. I am doing two coaxials, one on my current MK rig and the other on the DJI one.

The good news is that the 4S handles the FS700 fine. The bad news is that it really drains the battery fast.with two 6200's in parallel you will get about 7 to 7.5 min of safe flight time. I got 5 min of flight time offof one 8000 maH battery on th MK setup. The MK handled it but it did get hot. Theoretically these FF ESC's handle high current better so you should not get as hot as the MK BL's. I would get a IR thermometer to test that theory out.

You a better off though trying to accommodate a 6S setup for the best and safest results IMO.

Shaun

 

You're the best. Thanks again!
I'm still waiting the wire to connect my two systems ;-)
I give you some news when I do my first flight.
Take care.

Loïc

 

Let me know it goes I am interested in seeing how the A2 performs. I almost bought A2 but went with the WKM instead until it matures a bit with some of the bugs that will affect me with my spektrum controller.

 

I have just finished a build and upgrade of the CineStar 8 and utilized the WKM along with Castle ESC's and Tiger 3520-11 motors. Still in an original octo configuration. I am currently utilizing the FF 6S 9000 bats in parallel. Currently the rig weighs in at a hefty 14.5 lbs without gimbal and today I flew it at 24lbs with gimble and Canon 7D. The thing I am still not too happy with (well there are a few but . . . ) is flight time and battery efficiency. I am getting a total flight time with the DSLR of about 5 minutes before the voltage is reduced to the minimum, while the batteries are never more the 30% depleted of amps. Motors and everything are very cool after a flight so there is no heat build up which is very nice.

When I flew the original setup from QC I used the 4S 6200 bats and saw the same basic results. I would fly the DSLR and get a max of 5 minutes with the batteries in parallel. The voltage would drop to the minimum but the amps would never get used hardly. I consulted a friend and his immediate conclusion was that there simply wasn't enough battery on board to allow the copter to fly long enough.

With this conclusion in mind I did decide to test the theory by doubling the batteries. This means that I flew 4 4s 6200's on the copter with the DSLR. What was really interesting was that although I was at 24lbs. (severely over weight for the original design) I got flight times of 8+ minutes and the bank of batteries were actually finally utilizing the correct ratio of volts and amps. I found that all batteries were roughly 70% depleted of their amp capacity when the volts dropped to their lowest point.

Any thoughts about this. I am, as we are all, interested in extended flight times. This new configuration is capable of very heavy lifts but the battery life, and thus flight times are troubling.

Just as a note the WKM is very different to fly then the MicroKopter FC. The biggest issue that I have with the system is the fact that the stick position of the throttle is not a true reference of power input to motors. It is a true fly-by-wire since the FC is deciding the amount of power to feed the motors when at 50% stick input. no matter how much weight I load on the copter the stick position for hover is at 50%. This doesn't allow me to be actively judging the power requirements of the copter as it is in MK. It also makes a controlled decent and ascent a bit of a guess as to move up I have to guess where to put the stick for a speedy ascent and when i wish to descend I am not able to judge by my stick position the amount of power I am taking away from the motors. The biggest evidence of this is during takeoff. You have to get the throttle above 50% before the FC will decide to power the motors up enough for lift off on its own. This take off issue can also be compounded by the fact that the "Atti" mode that they recommend is not just attitude control but altitude hold as well. There is no separate altitude hold.

Just some observations. Hoping that when i can try the APM system it will have a more consistent performance but for now it is a pretty easy system to fly and utilize.

I have to say that for anyone converting from MK to DJI pay close attention to more wiring to the FC. If you wire it the same as MK the system does so aerobatics that you wont be ready for. Took me a few days before i realized that i had things crossed without even thinking about it.

 

G'Day Steve,

What size props are you running, those flight times don't sound to flash. I am running the 3515-15 motors with 15" carbon props, and using the same batteries, FF 6S 9000mah. My rig without the gimble attached will fly for ~25 minutes, and when I add a the 2-axis gimble and D800 to it flight times are still between 13~16 minutes and that is only using a single battery.

Are you on 500mm booms with large enough props for the job?

Cheers

 

Not as of yet. I will be getting those in a few days but at present I am using the CS8 stock 450's with APC 14x4.7 props. It has been discussed on various threads that the use of CF props don't extend flight time though (AFAIK). So that is very curious. I am sure that the Tiger props will make a good bit of difference though as they are actually designed for multi-rotor compared to the APC props for planes.

Approximately what is your AVW? As I was saying that my AVW today with the DSLR was just a bit over 24 lbs (10.88 Kilos)?

 

I don't think the issue is as much weather the props are carbon or wood, as the size of the rotor disk created, I suspect you will get better flight times, just moving to larger props.

How does your flight times compare to the ecalc results for your setup?

 

Chris I have attempted to fill that out and use that tool but for some reason I am unable to provide it with the proper information to get any results. It has been of no use to me at this point. I will need to get some real time to play with it more to understand and use it properly.

 

That's good advice, I found that out by reading some of the threads before. I think those last 2 PWM's were meant for Gimbal than the Octo as an after thought.

For those who are unaware the motor PWM go in this fashion. Its not intuitive and can be missed if not careful. Had it not been for the forums I am not sure I would have caught this tiny detail myself.

6
5
4
3
2
1
8
7

The good new is that this is corrected to be more intuitive on the A2.

Shaun