Hi i would like to build a 8 motor drone to lift at least 10kg. My idea is to take a 4 motor frame and put 4 straight and 4 inverted motors (just below). I like the matek f222 se but it has 4 pin (for 4 esc). But logically i will use 8 esc (for the 8 motors). So what i can do ? And for the software part is it the same as a 4 motor drone ? (Inav)
 Thank you.

8motors are nice to carry weight, a huge cam.
if you do it with 5inch rotors, if we do the bill with 1,7kg thrust per motor 13,6kg. you should be able to liftoff on 10kg uaw. 6inch would give more spare spare thrust, personaly i would go for 6inch.

https://rotorbuilds.com/search/x8
i believe you would just need enough uarts to remap them to additional motorsignal pads, not sure

(26-Jan-2021, 12:29 PM)hugnosed_bat Wrote: 8motors are nice to carry weight, a huge cam.
if you do it with 5inch rotors, if we do the bill with 1,7kg thrust per motor 13,6kg. you should be able to liftoff on 10kg uaw. 6inch would give more spare spare thrust, personaly i would go for 6inch.

https://rotorbuilds.com/search/x8
i believe you would just need enough uarts to remap them to additional motorsignal pads, not sure

Thanks for your fast response  and the link i will use a zd 680 frame . So i have a lot of space to install 15 inch porpeller. But do i have to use a specifique flight controller/software for my project ? I will carefully inspect the website to see if i can find any solution 

you wont need 8motors to carry 10kg by 8motors on 15inch, i beleive even 10" on 4motors should give spare thrust.
the benefit of an x8 is the relatively small wingspan to the motorhtrust, if you dont need the small formfactor, big x4 might make you happy if you dont like to stay small.
but i would like to see an x8-xclass build.

i asked a buddy, fly an x8. he used the matek f722 mini which provide 10 motorsignal pads by default. it would be also possibal by remap uarts and led pads.

(26-Jan-2021, 12:47 PM)hugnosed_bat Wrote: you wont need 8motors to carry 10kg by 8motors on 15inch, i beleive even 10" on 4motors should give spare thrust.
the benefit of an x8 is the relatively small wingspan to the motorhtrust, if you dont need the small formfactor, big x4 might make you happy if you dont like to stay small.
but i would like to see an x8-xclass build.

exactly but if i need a 30 kg thrust version i will need a x8 . With 3.750 g of thrust for each motor i would be fine .
For the 10kg version what would you recommend x8 with less powerful motor or x4 with these 3750g motor ? Taking flight time in consideration

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(26-Jan-2021, 01:06 PM)hugnosed_bat Wrote: i asked a buddy, fly an x8. he used the matek f722 mini which provide 10 motorsignal pads by default. it would be also possibal by remap uarts and led pads.

interesting that means that i dond't need a PDB

(26-Jan-2021, 12:47 PM)hugnosed_bat Wrote: you wont need 8motors to carry 10kg by 8motors on 15inch, i beleive even 10" on 4motors should give spare thrust.
the benefit of an x8 is the relatively small wingspan to the motorhtrust, if you dont need the small formfactor, big x4 might make you happy if you dont like to stay small.
but i would like to see an x8-xclass build.

oh i see . So i think i wil go for a 4 motor drone and if needed a x8 will do the job for approximately 30 kg of thrust
But i a afraid for the flight time of both drone

I fly a hex with 14x7 props, a quad lifting that kind of weight may stress the bearings in the motors so failure can occur quickly. Most hobby grade motors have no thrust bearings. The entire axial load (prop thrust) is transmitted by the side of the roller race, this causes the balls to "skid" around the races causing accelerated wear/failure.

It can be done with a quad but will be a happy flier with 8 motors, also a little quieter.

(26-Jan-2021, 04:06 PM)livefpv Wrote: I fly a hex with 14x7 props, a quad lifting that kind of weight may stress the bearings in the motors so failure can occur quickly. Most hobby grade motors have no thrust bearings. The entire axial load (prop thrust) is transmitted by the side of the roller race, this causes the balls to "skid" around the races causing accelerated wear/failure.

It can be done with a quad but will be a happy flier with 8 motors, also a little quieter.

So a 4motor drone can't lift 10 kg ? even with particular parts ? I will use these motors 2.750 kg of thrust  

i dont use it by myself, a comparison of x8 and x4 in ecalc software might be good to get an impression about efficiency.

i beleive x4 might be more efficiency, but x8 could provide power to do acrobatics on a heavy quad and heavy cam.
you would need at least 30kg thrust to do acrobatics on 10kg uaw; a powerloop, rolls and flips. i guess there could be benefits from x8; rare power but not efficiency.
if alot spare trust is there, you would be able to come home if a motor stoped to work, it could be more save somehow compared to a x4, otherwise the chance to get faults is increased by 8motors compared to 4. a difficult question between benefits and downsides.

x8 have some downsides about battery choices and matching escs, there could be downsides.

(26-Jan-2021, 04:32 PM)hugnosed_bat Wrote: i dont use it by myself, a comparison of x8 and x4 in ecalc software might be good to get an impression about efficiency.

i beleive x4 might be more efficiency, but x8 could provide power to do acrobatics on a heavy quad and heavy cam.
you would need at least 30kg thrust to do acrobatics on 10kg uaw; a powerloop, rolls and flips. i guess there could be benefits from x8.

x8 have some downsides about battery choices and matching escs, there could be downs

My bad i forgot to say that the drone is for delivery/drop salt on the road against ice.So acrobatic moves doesn't interest me. Over all i think i will go for a x4 with 10000mha batterie 6s.
what do you guys think ?

hehe good salty thing :-)

if you can, i would use the highest possible voltage, 8s/10s/12s
batteries dont like cold conditions, if you doesnt do any preheat or casing save the battery befor temp, the current can be a risk.
if you use higher voltage, you might get less risk for battery errors by less current draw.
8-12s might need expensive xclass gear, adp escs and a huge pdb. 4x an adp esc = 500bucks, plus the pdb? i guess again about ?150bucks?
probably it doesnt make sense about price increasement but worse to mention about.

(26-Jan-2021, 04:54 PM)hugnosed_bat Wrote: hehe good salty thing :-)

if you can, i would use the highest possible voltage, 8s/10s/12s
batteries dont like cold conditions, if you doesnt do any preheat or casing save the battery befor temp, the current can be a risk.
if you use higher voltage, you might get less risk for battery errors by less current draw.
8-12s might need expensive xclass gear, adp escs and a huge pdb. 4x an adp esc = 500bucks, plus the pdb? i guess again about ?150bucks?
probably it doesnt make sense about price increasement but worse to mention about.

 .


Yes the batteries will be heated before any flight.
For 8 s batterie i need to find other motors and esc (x4) .This will be hell expensive i think. But theoretically (with my actual 6s config)the drone will have 15kg of thrust.( - 3or 4 kg for it's weight). So around 10-11kg of weight to lift . Do you think 10000mha batterie is enough for at least 20-15 min of flight time ?
Thank you 
I am sorry to bother you