Motor/prop selection

[yourameh]

I'm building a T-copter. The goal is aerobatics and FPV. I know a higher Kv, shorter prop is going to give me more aerobatic ability, but I'm also looking for efficiency in flight time for FPV.

Here are my current choices:

SunnySky 1400kv, 8047
real good response and thrust + smaller rotor = more stability for hover. A really aerobatic machine but only maybe 7min on a 2200mah loaded with FPV equipment

SunnySky 980kv, 9047
the maths claim 15% more efficiency, slightly less thrust, larger prop = less hover stability and less responsiveness but more efficiency.

I'm aiming for at least 10min FPV on a ~2700mah. Ultimately I'm not sure the g/w efficiency really matters because the quality of the motors are similar and I feel as if more weight = less fly time no matter what kinda motor/prop config you're using. I only really see it making a difference when you get into 6+ motors. Is this notion correct? Should I not worry and just go with the 1400kv?

 

[holtneil]

HI mate rule of thumb is lower kv more torque and can run bigger props, high kv faster revs , normally run smaller props so less friction in the air uses less battery this is where e clalc come in put all your spec in and see what happens to flight times
http://www.ecalc.ch/xcoptercalc.htm?ecalc&lang=en

 

[Blucraft]

Hi all,

It seems that a common question among hobbyists is how to choose a motor/battery/propeller combination. I've seen several tools out there like ecalc and WebOCalc that help with this selection process. How many of you use these? Are they trustworthy? What do/don't you like about them?

Thanks!

 

[Mike]

Hi all,

It seems that a common question among hobbyists is how to choose a motor/battery/propeller combination. I've seen several tools out there like ecalc and WebOCalc that help with this selection process. How many of you use these? Are they trustworthy? What do/don't you like about them?

Thanks!

I personally don't use any of that (as a starting point). I kind of base things on general principles and other builds I see that work well - and then I adjust from there. I will use those calculators to verify things, but not as a starting point.

 

[QuadrocopterCanada]

Try to use H250 frame type with small motors like MN1806 or MN1804. Battery is up to 1600 mAh. Flight Time around 7 minutes.

 

[holtneil]

Hi well i am running a talon v2 550 frame , AGM motors 650kv with 14x5.5 props , 2200 mah battery flight is about 6 mins , but if i run 5000mah it will be in the 10 mins flight time
i used to run 1100 kv NTM motors on 10x4.7 , they are nice and powerful but flight time is 3mins on a 2200mah ecalc did this would be a bad combo and it was right