heavy lift multirotor help

[timmytimmy]

Hi all,
i m planning to build a heavy lift multi rotor.desired payload is around 25-30kg.
any suggestion welcome.not fussy abt electric or engine based design.

Thanks in Advance

 

[crayfellow]

would a giant quad suffice (biased toward endurance with minimum/no redundancy) or do you have a configuration in mind?

what are your priorities between stability in wind, flight time, cost, portability (if so, within what dimensions or what type of transport), and redundancy/fault tolerance?

Also it would be useful to know the application.

 

[Carapau]

Timmy, what's your background in multirotors if you dont mind me asking?

 

[violetwolf]

Yes, what is the payload are you trying to fly? Camera copters have different requirements than surveying copters etc.

 

[crayfellow]

Timmy, what's your background in multirotors if you dont mind me asking?

I'm picturing this.

 

[timmytimmy]

Thanks for the reply guys .
@crayfellow i m quite happy to go with any configuration as far as its efficiency and perform is good.
happy to spend around 15-20k and would expect a flight time of atleast 20mins .normal wind condition and would definitely need a stable flight and easy to fly.
main purpose is for agricultural use like spraying ,crop dusting etc.
@Carapau
I m an qualified Aircraft Engineer
got no previous experience with multicopters.

 

[timmytimmy]

I'm picturing this.

@crayfellow thanks for the video,basically that configuration of quad would definitely do my job .
but dont see a good flight time on it and seems very unstable.

 

[crayfellow]

I was joking.


Sent from my iPhone using Tapatalk

 

[Carapau]

Timmy thanks for the response. I think the best way to get your answer is to learn about building multirotors first. Aircraft engineer or not, there is quite a lot of specialist knowledge in the electronics here and how the flight controllers work etc. Undoubtedly your knowledge will help but going big straight up is not an approach I would recommend. Start with something like a 550 and as you go through this you will start to be able to identify that which you need for a 'big' project. Diving straight is likely to end in a big pile of expensive gear.

I recently helped out on a University project with some very bright engineering students. They undoubtedly knew far more than me in general terms but the whole exercise proved that they also lacked in general RC knowledge which ended up in nearly all of the aircraft crashing at some point. Not their fault but it shows that deaper knowledge in the specialist area is worth obtaining.

 

[Carapau]

Anyway, to get your grey matter humming, look at using an x8 or flat 8 machine using 28ish inch props but make sure you look at high torque motors for these. Just bear in mind that one 28 inch prop set can cost in the region of £200 pre pair and a good motor would could cost £250 each so that's £2000 on motors alone hence my thoughts on starting to learn on something small first.

 

[timmytimmy]

@Carapau u r definitely right abt going to a small one before i take on the big project. infact there is shipment coming soon for a 450 size quad from hobby king.
thanks for the advice on flat 8,i was thinking similar like that.flat 6 or flat 8 using T motor brand 100kv .link for the motor
http://www.foxtechfpv.com/tmotor-u8-pro-kv100free-shipping-p-1450.html

A small question regarding the control board,might sound silly but please bare with me .thanks
imagine i ended up building a quad using 100kv motor and suitable esc,battery etc. If i have a spare control board and sensors from anyone of the well tested brands like dji or something .will i be able to use the same board directly onto my quad without much hassle or is it a complete differnt ball game.

Cheers
Timmy

 

[timmytimmy]

@Carapau i am definitely aware of the cost involved in this project.every information from experienced guys like you and others are really vital n important for me

 

[violetwolf]

Tim, for flight controller I'd recommend having a strong look at PixHawk. Save a thousand or two and get a supior controller.

I personally avoid all DJI products (toy quality imo)

 

[violetwolf]

In fact I'm almost 100% in the open source for electronics these days. Radios included (Taranis in that dept). The open source stuff has a more engineered feel compared with the "product design" feel of most of the retail stuff.

 

[Pumpkinguy]

A very heavy load like 25-30kg with a long flight time is the hard part. Correct me if I'm wrong here but take off weight will quickly drop as the payload drains out.

I picture a very large flat octo frame with a motor/prop combo that provides at least 3000 grams of thrust at 50% throttle.

You need to talk to Andrew @Hexacrafter. He is in Ohio and builds the strongest frames on the market. He will work with you to reach your goals and not bend you over on cost.

 

[violetwolf]

A very heavy load like 25-30kg with a long flight time is the hard part.

I was going to mention this as well. It's a case of diminishing returns: More weight to lift requires bigger batteries and motors which brings your weight up even more.. and round and round you go.

Another place to look at for long flight times/heavy loads is a copter that Mr. Fu over at Foxtech developed. He calls it the Devourer http://www.rcgroups.com/forums/showthread.php?t=2213490 It'll fly over 50 mins with no load. And he's managed 19 mins with a 7kg payload (18kg AUW)

I think that is about your upper limit on flight time / payload

And not suggesting you buy one, but rather have a look at the process Mr Fu went through. He has his hands on anything he wants so it's a good bet he's found good combos

 

[violetwolf]

A lot of the agriculture guys are using fixed wing for this reason. Maybe a large biplane would be more efficient?

 

[Pumpkinguy]

I just remembered this from a while backView attachment 26004
20 minute flight time.

 

[maxwelltub]

I think a gas or turbine collective pitch is the way to go. You will have hours of flight and be able to lift your weight.

 

[Jason S]

The only thing i have seen that does that kind of payload and flight times is the crop dusters in japan. The thing is huge dangerous but gets the job done I have seen bigger ones than this just a example of rc madness

Just need a small truck to transport though!