Suggestions for electric parts for a 30 min flight time?

[Pavery]

Hi all,

First post so be kind

I have done a lot of research and read sooo many forums regarding multi rotors and so I have a good understanding of how they work, fly etc. but I now require to build my own for my senior design project. I am aiming to build a hexacopter with a flight time of around 30 mins, which will weigh all-in approximately 2-2.5kg. I would also like to have FPV, but very basic so no gimbal etc just a small camera which can send live feedback.

Reason being a hex is because I want it to be stable enough in winds of about 25mph whilst having good hover capabilities.

I have done a lot of research and tried to find motors and props to use, and looked at different mAh batteries but I can't find a good enough combination, probably because of lack of knowledge. I have seen others with similar quads/hex/octo's on youtube etc with very long flight times and so I know it's possible.

Can anyone suggest to me potential motors/props/batteries/components I could use. Also, do you think a hex could cope with winds? What about other frame types, such as quad or even coaxial?

Criteria

1) 30 minute flight time
2) FPV
3) Stable in 25-30mph winds

Any help from people would be greatly appreciated

 

[rcflyer729]

a quad and a hex really are not going to be different It is more about the flight controller so I would recomend the naza m lite with has gps and will greatly help in the wind.
I would build a quad It would be a lot cheaper and easier to build
The sunnysky 980kv motors work awesome I am using them on a quad and with 2 5000mah battery's I get 20 minuets of flight time and still have plenty of power so you might be able to get 3 5000mah ones
these escs would work well http://witespyquad.gostorego.com/sp...rmal-esc-with-rapidesc-fw-for-multirotor.html
I use 10x4.5 props with those sunnysky motors

 

[rcflyer729]

Here in the link to those motors they are a little more expensive then other motors but they are well worth it
http://www.buddyrc.com/motor/multirotor-motors/sunnysky-x2212-13-980kv-ii.html

 

[Pavery]

Cheers for the quick reply!!!

I have looked at the DJI Naza and was going to get one of their flight controllers. I had posted this topic on RC Groups also but haven't received any replies yet :/ that was from yesterday.

As for the batteries could I not get a larger mAh one rather than having 3 separate batteries?

But again, thanks for your specs, I will definitely look around for similar motors or maybe even use the same, but not sure if I can get them in the UK. I'll check on hobbyking.co.uk and see, I'm not too fussed about price as long as as they're no more than £30 which is a fair amount anyway so most motors should be available to me

 

[rcflyer729]

I am sure you could use a bigger battery but once you get over 5000mah most charger and only charge a 5amps so you have to charge it really slow also I like being able to just put one battery one for a short 10 minuet flight. I would think you could find the sunnysky motors in the UK somewhere they are very common

 

[Pavery]

Okay, thanks for the advice.

I'm going to do a little research on motors and power consumption, and hopefully I'll find something that can meet my specifications.

I wish it was such a simple task but there's so much maths and other factors to think about.

If only someone who had something already existing similar to my specs could tell me the basics to what they're using

 

[RichB]

ecalc.ch has tools for calculating the approximate flight times for various motor setups. For your situation it is going to be invaluable.


Your 2-2.5kg weight is almost a deal-killer. Are you required to carry a specific payload?

Throwing batteries at a multirotor gets you diminishing returns. A multirotor that flies for 20 minutes with 2 batteries will not fly for 30 minutes with 3 batteries.

At some point, adding more batteries will not give you any longer flights.

That point is determined by the weight of the frame before you put batteries on, and the efficiency of your motor/prop combo.

You want to hit 30 minutes: you need to get your frame as light as possible and get the most efficient setup you can.

Large props spinning slowly are much more efficient than smaller props spinning fast.

You've already been pointed towards some 10" props and ~1000kv motors, but in my humble opinion, you need to start looking closer to 16" and kv ratings in the 300-400 range. Also, 4 to 6-cell lipo packs instead of the more common 3-cell so you can keep your current draw down and make up the power with voltage.