Hello guys,
I am trying to design a hexacopter with APM 2.5. The aim of the project is FPV and efficient flight time ( more than 8-10 min even 15 min). As far as i see, besides many other factors, the impotant ones are small KV and large propellers. There fore i decided to use 14 x 4,7 props with the motors above.
Sunnysky v3508 380 kv :
RC timer D5010 360 kv :
My question is which one is appropriate for my aim and may i be successful with this configuration for my purpose.
This is different from topic but if you can answer i will appreciate it. In the motor tables, there are two or three different voltages for the same props. Why is this difference ? Furthermore, for example for 14 x 4,7 props motor table says 11.4 and 14.8 and sometimes 18 so 3-5 S. If I use 3S battery what problem do i counter with ?
Thank you
Replies
I'm getting some pretty good times on my 4s 5000mah battery and 5010-360's from RC-timer. Running 1555 props from RCtimer as well. Getting a solid 15minutes, possibly 20 minutes with FPV (gopro3, gimbal, transmitter).
Check out my video and specs.
https://www.youtube.com/watch?v=Xdo5brnvK1I
I am still fairly new at this, but I will try to answer your questions. In order to best size your motors, you will need to know approximately what your flying weight will be. You are right that lower KV and large props are helpful in achieving more efficient hover and therefore longer flying times, but you have to be mindful of at least two things: lower KV motors sometimes have lower power handling ratings, and larger props take longer to accelerate. This may affect the control of your hexa, but someone with more experience than me would be able to address that more completely.
The Sunnysky motor looks reasonable on paper (again, from my very limited experience), and I've heard good things about the brand, but I have no first-hand knowledge of them. The other motor has very limited data, looks very thin, and recommends a 10A ESC - which leads me to doubt if it can handle the power you will need to fly.
The different voltages are listed to cover different battery pack options. The major difference is that a higher voltage pack will give you a higher top-end throttle setting - if your motor and ESC can handle the additional power. If you use too small of a battery, you might not have enough control authority or ability to climb. If you use too large of a battery, you might overload one or more components.
My recommendation would be to start with a kit with known/reasonable performance for your first quad/hexa, and then experiment with upgrading different components one or two at a time (motor+prop combo, for example).