cookmangr
(Dimitris Arampatzis)
1
I have a X8 coaxial with sunnysky 3508 700kv motors and 13×5,5 on the top and 12×5,5 on the bottom
I want to check the difference at RC Out PWM
I see at my logs that there is RC OUT 1 RC OUT 2 etc
What are the front left motors RC OUT ?
Is it like in this picture ch2 and ch5 ??

OlivierB
(Olivier Brousse)
2
Yes. BTW there’s a good discussion of coaxial setups and efficiency in section 4.4 of this paper, especially influence of disk loading if you haven’t seen it or are interested:
https://www.researchgate.net/publication/304817071_Influence_of_propeller_configuration_on_propulsion_system_efficiency_of_multi-rotor_Unmanned_Aerial_Vehicles
1 Like
cookmangr
(Dimitris Arampatzis)
3
Thank you olivier
Thank you for the link , i have read again simmilar posts
I m in a search of a 13×4.7 or a 14 ×4.5 prop
After my first successful flight i just change the setup of the props too have more knowledge wgat is going on
What i found
With 13×5.5 on the top and 12×5.5 the copter is very quite
The motors are cold and for hover it get 40A to 43Α
With 12×5.5 on the top and 13×5.5 on bottom the copter is very loud
The motors are again cold and it draw the same Amp for hover 40 to 43
At my logs i see a difference about 150 pwm
Now i m going to check 13×5.5 on all motors
cookmangr
(Dimitris Arampatzis)
4
Well i did a test with all props 13×5.5
Hover need 36Α to 40A and again it was quite
When i have one kilo of extra weight it needs 55A to 60A to hover
But if i travel for 13km per hour it also need 55A to 60A
It has very good stabillity in flight
I think this motors are too much for a coaxial setup