Droidworx AD-8 Octo Heavy Lift Extended V3 Version

homer911

homer911

Member
Hi all,

Im looking for some advice in this build please, I am new to this area so will need to be pushed a little.

I am looking to carry a Canon 5D MKII on the Droidworx AD-8 Octo Heavy Lift Extended V3 Version. I have been recommended the axi motors but not sure what type.

Also, I'm a little confused regarding the power distribution boards. Do I need one that will support the current flow from the motors ie. 50 amp motors X 8. Does this mean that the board must be min 50 amps? Do I need to allow for anything else. Does it matter how many motors there are? Sorry if these are really basic questions but I am new to these muiltcopter builds.

Also, will the esc's need to be min 50 amp as well?

I want to use the DJI WK M.

Also what about the battery/batteries. How many will I need. Also, what ratting? I'm thinking the higher the better?

Thanks a lot for the advice,
 

BorisS

BorisS

Drone Enthusiast
Hi Homer,

"I am looking to carry a Canon 5D MKII on the Droidworx AD-8 Octo Heavy Lift Extended V3 Version. I have been recommended the axi motors but not sure what type."

With the AXi 2814/22 you will be on a good track.

"Also, I'm a little confused regarding the power distribution boards. Do I need one that will support the current flow from the motors ie. 50 amp motors X 8. Does this mean that the board must be min 50 amps? Do I need to allow for anything else. Does it matter how many motors there are? Sorry if these are really basic questions but I am new to these muiltcopter builds."

This one is a little more complicated when it comes to a Octo. 50 A for the complete system is certainly low. Hovering and faster climbing will be possible, but when it comes to a safety maneuver for example full throttle with full payload to catch the bird it can become a problem. You have two options use two dist board and distribute the motors equally on the boards, that just a little tricky with the main lipo power connection, but doable.

Or you can just build your own power dist harness with a thick enough cable or copper ring etc.

"Also, will the esc's need to be min 50 amp as well?"

Nope with the axis you should be fine off with 30A to 40A ESCs. You have to plan ahead which voltage you want to fly with, 4s 5s etc. If you consider 5s or 6s it would be better to tend toward 40A ESCs, First of all because there are not so many 30A 5s 6s ESCS and you will need the reserves.

"Also what about the battery/batteries. How many will I need. Also, what ratting? I'm thinking the higher the better?"

Japp the higher the better but the higher the more expensive and heavier. You should be fine of with 25c with a certain burst rate. I mainyl fly those with my octo or hexa when using 4s http://www.hobbyking.com/hobbyking/store/__11940__Turnigy_nano_tech_6000mah_4S_25_50C_Lipo_Pack.html

Boris
 

mbsteed

mbsteed

aerial video centric
I am planning to use two Photoship One power distribution boards (80A max) not just because the board might not handle the power but because it adds another redundancy path - if one entire board goes down I still have a second with power and my octo turns into a quad. I use this on my X8 and never had a need but it provides a bit more insurance.

Check out this thread my build is similar to what you want to do.

http://www.multirotorforums.com/showthread.php?1647-Octo-Build-for-Aerial-Video
 
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homer911

homer911

Member
Ah, I now understand why I dont need the higher ratted amp ESC's. Cheers

Regards the bateries: Can someone explain to me what the difference is between 4s, 5s and 6s. I'm not sure what they mean. And would it be adviseable to put two in parallel to give a longer flight time. I know it would be heavier but would I not still get more flight time?
 

BorisS

BorisS

Drone Enthusiast
4s 5s 6s ..... indicates the amount of cells in a lipo, thus the more cells in a lipo the higher the voltage of a lipo.

A cells has 3.7 V so a 4s lipo would be 14.8 v, 5s would be + 3.7 so 18.5.

In a charged state a lipo cell gets up to 4.2 volts so a 4s will be 16.8

Boris
 


GGoodrum

GGoodrum

Member
No, not at all. Even though the motors might be capable of handling 50A, you won't get anywhere near that for this sort of setup.

Also, most any power distribution board can be made to handle more current. All you have to do is flow some solder on the traces, to build them up. I've used this technique on setups for ebikes that handle up to about 150-200A bursts.

-- Gary
 



homer911

homer911

Member
Yeah, the point I was trying to make was, you still do not know the load capacity of the board. Unless you test it physicaly. No?
 

homer911

homer911

Member
I still cannot find enough info on what power distribution board to use for my octo. I have seen posts about building my own but I would like to buy one. Most of them only carry up to 80 amps, I dont think thats enough for what I have. Any advice?
 

DucktileMedia

DucktileMedia

Drone Enthusiast
If you are really that worried about it just go buy a steel or copper washer and solder all your main wires to it. Cant go wrong there it's just not as light and it's a bit harder to assemble.
 

homer911

homer911

Member
How can I figure out how much load will be running through my power distribution board. Is it just the max amp draw from my 8 motors? Obviously, if I was loading a camera mount it would have to include that as well. Do I have to take into account the DJI controller etc?

Cheers
 

BorisS

BorisS

Drone Enthusiast
homer911 you are getting a little too worried ! The max A draw from your motors you will never reach ! Have you looked at your configuration in ecalc.ch. One dist board for a hexa and than flown in WKM attitude mode its certainly enough. An octo with one dist board can reach its boarders in the worst case heating up the dist board and reducig the overall performance if your bird which can lead to failure. But like IrisAerial said than use a think cooper washer or take two dist boards and you are on the super safe side !

I just ordered two abusemark boards and i will connect them over their lipo connects to each other and distribute the motors evenly on them. One thick 12 or 10 awg cable to the bottom distboard and it finished.

Boris
 

homer911

homer911

Member
OK, maybe I'm thinking too much into this!! : )
connect them over their lipo connects to each other and distribute the motors evenly on them. One thick 12 or 10 awg cable to the bottom distboard and it finished.
Click to expand...

Would you mind explaining this a little more for me? So, are you going to connect one battery to it own board and then evenly distribute the motors. The thick 12 or 10 AWG cable...... will this connect the bottom side of the board to the battery terminals? Thanks.
 

BorisS

BorisS

Drone Enthusiast
the two dist board would probably be still lighter than any distribution ring or wiring etc. just keep the cables from the ESCs to the dist board as short as possible to reduce weight.

If you dont want to lipos than just take one away is clear. I actually prefer flying with one 8000 mAh lipo than connecting two, but whatever thats just a question of taste etc.I am lazy :)

Version two might be better since the first soldering joint to the first board is stressed less. But it probably will be heavier since you need more cables for the lipos, thus more issues with the frame if its fits and more potential magnetic fields from the cables etc.

View attachment 2188

the nice thing about the dist board is that you can easily desolder ESCs and put them back etc. Dist wiring spider etc are always a hassle doing that removing the isolation etc. You should over the dist board though with liquid tape once you are finished with soldering !

Boris
 

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BorisS

BorisS

Drone Enthusiast
like this,

View attachment 2189View attachment 2190

the soldering hole in the afroboard/abusemark are to small for a 10 awg cable, you have to sculpted the cable a little and solder it from both sides that is have enough contact. Little tricky when adding another board but you will manage !

Boris
 

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T

Totallycommitted

Member
Liquid tape Boris Thank you I have looking for that solution any suggestions on where to buy from ?

Awesome thanks

Matt
BorisS said:
the two dist board would probably be still lighter than any distribution ring or wiring etc. just keep the cables from the ESCs to the dist board as short as possible to reduce weight.

If you dont want to lipos than just take one away is clear. I actually prefer flying with one 8000 mAh lipo than connecting two, but whatever thats just a question of taste etc.I am lazy :)

Version two might be better since the first soldering joint to the first board is stressed less. But it probably will be heavier since you need more cables for the lipos, thus more issues with the frame if its fits and more potential magnetic fields from the cables etc.

View attachment 3415

the nice thing about the dist board is that you can easily desolder ESCs and put them back etc. Dist wiring spider etc are always a hassle doing that removing the isolation etc. You should over the dist board though with liquid tape once you are finished with soldering !

Boris
Click to expand...
 

T

Totallycommitted

Member
Hey Homer, I have pretty much exactly that same setup you are going for ....an okto with wkm with 40amp esc power distribution board and am using 4 cell Turnigy nanotech 5000mah rated 35-70c batteries with pulso 760kv motors and it,s a good setup. I am also using an Av200/360 Cam gimbal. I can use 13 inch props but am also going to try 12 inch to see if it makes it just that little bit better.

My thoughts on batteries are pay a bit more and get a better c rating ( Batteries are the blood in your oktos arms). Also definitely go with 4 cell or more as 3 cell will give you less revolutions for the same amount of power consumption.
On esc use the 40amp because a little bit extra adds to the safety value and the will reduce the overall electrical stress (maybe not that much but i,d rather be on the safe side.
Can,t go wrong with axi motors. that said I,m using pulso motors and they are great so far....
DJI WKM is the boss !
Using two 5000mah batteries in parallel (together) will give you a safe 12 minute flight time never push your flight time, check how long a voltage lasts on your battery and then shave 2 minutes off flight time and you should always land in 1 piece...a perfect landing.

good luck

Matt
 

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