Reading through the section and I noted that someone mentioned that large prop sizes could overwork the motor. If this is true and I suspect it is, is there much of a difference on 10x47 props verses 11x47?
I’m currently building a X8 all carbon fiber copter with 2x 4in1 25A ESC running 880Mv motors.
I plan to use only 4s batteries minimum of 6400 mAh and may go larger later.
So I’m wondering if I should stay with 10x47 for push and pull or use larger size (11x47), or mix them. And will 11x47 props diminish my motor’s life span?
Any suggestions would be helpful.
Not too much difference, although more power and payload capability will be available with the 11x4.7’s but with potentially shorter flight time if that power is used.
I had 11x4.7’s on a quad which flew fine but when I put camera and video transmitter on I was not able to stop a descent near the end of a flight.
Also slightly less nimble with 11x4.7’s as they turn slower, possibility of increased rolling shutter effect on CMOS cameras depending on the prop used - again due to slower rotation
Theoretically lower current consumption with 11x4.7’s but not necessarily in practice
Hello there.
I new to multirotors, although I have been flying RC planes for many years .
I am flying dji450 Quad with APM2.6 +GPS+ Compass.
I am also using a high plastic landing gear for FPV,(Probably in the future) and I use a Turnigy 3s 5000mAh lipo.
When I use the stock 8 x 4.5 propeller it seems too heavy and flyies stable , but when I switch to APC 10x4.5 OR 10X 5.5 (the props are properly balanced), the quad takes off quick but starts to wabble or acts like a crazy pendulum oscillating and it becomes uncontrollable.
I have tried different props but I don’t seem to fix the problem.I no longer have The original black DJI 10x4.5 props that comes with the kit and they don’t seem to be available anywhere.
Is there any adjustment or parameter setting that I can work on to make the quad fly stable .
It is really driving me crazy.
Hope somebody can suggest something. Thanks all in adavnce
i would suggest you consult the documentation for the motor to determine the best prop size to use for a 4S setup.
the way i understand it is, you must consider the correct size ESC for the motor A rating (e.g.) below i have provided specs on a NTM Prop drive Series 28-30 900kv motor. the motor has a current rating of 18A therefore, you will need an ESC that is around 20% - 25% higher i.e. around 22A or more. 25A - 30A ESC is recommended.
you will also see below, suggested prop sizes for 3S setup showing the power in W (watts) and the A (ampere) consumed and the thrust expected in kg.
you will note: the larger the prop the greater the power (W) the higher the current (A), but they are all within the motor’s safe current rating of 18A. if, for example, an even larger prop was used then, the current needed to spin the prop will exceed the safe current rating of the motor and cause it to burn out or the ESC to break.
also observe as the voltage of the battery, lipo, increases (3S 11.1v (12.6v fully charged) to 4S 14.8v (16.8v fully charged) the prop size is smaller because the increased voltage of a 4S setup will make the motor spin faster. you will have to be careful here because, the temptation to use a larger prop may result in a burnt motor or broken ESC because of the increased current used.
i hope i was of some assistance. all the best with your project.
Specs:
Model: NTM Prop Drive Series 28-30S 900kv (short shaft version)
Kv: 900rpm/v
Max current: 18A
Max Power: 215W @ 12v (3S) / 270W @ 15v (4S)
Shaft: 3mm
Weight: 66g
ESC: 25~30A
Cell count: 3s~4s Lipoly
Bolt holes: 16mm & 19mm
Bolt thread: M3
Connection: 3.5mm Bullet-connector
Prop Tests:
13x4E - 11.1v - 194W - 17.4A - 1.04kg thrust
12x6E - 11.1v - 195W - 17.8A - 1.01kg thrust
11x7E - 11.1v - 188W - 17.0A - 0.89kg thrust
10x5E - 11.1v - 133W - 12.0A - 0.75kg thrust
9x6E - 11.1v - 120W - 10.7A - 0.68kg thrust
9x6E - 14.8v - 234W - 15.8A - 1.05kg thrust
8x4E - 14.8v - 159W - 10.6A - 0.75kg thrust