Hey guys,
I am thinking of making a multi with a payload capacity of atleast 6-7 kg and I need your suggestions regarding it like which one should I make.? hex or octo, links for heavy lift motors and propellers, etc.
Waiting for replies.

No replies?? 
ok here are some inputs.
We decided to make an Octacopter.
I am considering this motor to be used on 3S with 15" prop.
http://www.hobbyking.com/hobbyking/store/__19831__NTM_Prop_Drive_Series_42_38_750kv_785w.html

Specs:
Model: NTM Prop Drive Series 42-38 750kv
Kv: 750rpm/v
Max current: 55A
Max Power: 403W @ 12v (3S) / 785W @ 15v (4S)
Shaft: 5mm
Weight: 169g
ESC: 60A
Cell count: 3s~4s Lipoly
Bolt holes: 25mm
Bolt thread: M3
Connection: 3.5mm Bullet-connector
Prop Tests:
13x10 - 11.1V - 344W - 31A - 1.79kg
13x10 - 14.8v - 740W - 50A - 2.8kg
14 x 6 - 11.1V - 403W - 36A - 2.23kg
14 x 6 - 14.8v - 785W - 53A - 3.05kg


This is the simonk flashable ESC that I am considering to buy
http://www.hobbyking.com/hobbyking/store/__12191__TURNIGY_TRUST_45A_SBEC_Brushless_Speed_Controller.html

And we need maximum flight time so there will be 8 Lipos for 8 motors,
we are thinking about this zippy 3S1P 8000mAh battery.
I need your valuable suggestions on this part list.

Thank you.

8 lipos for 8 motors?? what do you mean by that???

This is not a good idea to use 8xlipos
So.e lipos may drain soon some slowly.. so that each motor qont get the same power input hence ot will effect the performance..
And for a heavy lifter the motor you choosed is something like suicidal..
Choose motors which are low in kv around 300 to 400
And choose bigger props with 6s lipos
Like tarot 5008
You can use 18inch prop and 6s lipo.
Easily it can produce 1kg thrust with just 3A consuption..
I am building a hexacopter with tarot 5008 and 18inch prop..
Using 2x 6s 6000mah lipos 35c
Not yet installed the gimbal.. it can give a flight time of around 31min now..
With 5.4kg auw..
Now time to add the payload..

Here are some pics

Good work arun 

@aniket: I mean a separate Lipo for each motor.
I was inspired by this Rc group thread: http://www.rcgroups.com/forums/showthread.php?t=1372744

That's an awesome hexa arun.
And thank you very much for your suggestion, So is it possible to have 30 min flight time with 6 kg payload.??

Lifting of in 40% trottle.. and hovering at mid throttle for 20min plus.. after that need to control our self as the lipo is getting low...
30min is something possible.. but your idea of 8x8000mah lipo will kill the octa..
How can u assume a 6kg auw for this octa.. even the lipo weighs more than that right?
Limit your lipo inside 15000mah
Also while selecting the motor take good care of..

Go with what Arun said. 8 lipos for 8 motors is suicidal 

Thanks arun n satya.
I'll go for 2 or 4 Lipo not 8.
and 6 kg is not AUW it's the payload, so total AUW would be around 10-11kg.

11kg auw with these ntm motors..?
Then your flight time is going to be less than 5 min with 15000mah lipo
Go for lowe kv motor..
Sunnysky is a good choice.. if budget allows then T-MOTOR OR AVROTO series..
First choose form base.. that is the multirotor type then frame , then gimbal then electronics which fit for your job and the frame..
May be a hexa , octo , y6 , x4 octo what ever may be... depends upon your need..
Now finally time to choose the battery..
Entirely depends upo  the A consuption(rough calculation)
Flight controller depends upon your budget and skill...
Naza is an easy one and in budget for a biggie like this..
Apm works similar low budget need more time to program or pid tune..
Wookong more budget and more reliable..
And the list go on...

We have been working with the I flight motors being their distributors and find them to be good value for money both for Gimbal motors as well as the multis ,you will find some good reviews of them on RCG as well when it comes to Multi motors . Yes lower KV's is the way to go.
E Mail sai@rcforall.co.in if you would be interested in I Flight . They also have some High Voltage, 4 ESC's in one etc very focused on Multi's.

Please update a list of motors available with a tested thrust chart ..
Which will help a lot to choose the motors..
I am using iflight motors in my brushless gimbal 180T and 150T , works really good..
If available locally it would  be very helpfull..

Arun bhaiya i have seen that hexa frame elsewhere on the forum, is it the same one that rahulvyas had?

Looks amazing in flight

Hello sajid wish you good luck when you will build surely post the pics and Arun Sir really awesome Copter really salute you

RC neil: NO.. :p
That is a tarot 690mm frame
Mine is a 1000mm hexa frame..

Thanks aman

Thanks arun and aman.
yes arun, I decided to make an octa n will be using APM.
But this motor, battery calcualtions are killing me, can you suggest me links where I can hunt for big motors.

you can check out www.hobbyking.com

Arun's build is amazing and as he said, 5008 motors are the best!
just get 6s and a 17" prop, you will get about 30min flight time easily with a 8000mAh battery!
And arun's frame is the best u can go with, get it soon.
or u can buy tarot 960s with 5008 motors, that will be a hexacopter but a less payload capacity

And APM is a nice choice, just install the new 3.1 firmware and you are ready! also dont forget to configure failsafe settings.

thank you Rahul. 
I am going for 5008 motor.
btw arun from where did you bought those motors.??

Btw Folks I found this one similar to tarot 5008 on Hk.

http://www.hobbyking.com/hobbyking/store/__45282__5008_340KV_Turnigy_Multistar_Multi_Rotor_Motor_With_3_5mm_Bullet_Connector_Installed.html
Power, current everything is same should I got for it or for tarot.?

Both are similar and the prices as well...
You can go for either..

Tarot-rc.com

Hello Arun sir did you get custom hassles ordering from Tarot-rc.com

No custom hassles but sure customs duty..
;)

Haha Thats A good one arun sir thats true we will get customs duty charged