I'm making a quadcopter and have 3 Dys 2300kV motors and one Dys Bx 1806 2700kV motor. I need to use all these motors together how can i use them together, can someone please help me?

I don't think it is possible to use a different motor on a quad....you need to have all similar motors delivering equal amount of thrust ....you need to have all 4 motors of either 2300kv or all 2700 kv
Regards

Yea that's what i was afraid off...
Thanks though 🙂

you can still try (at own risk)... since the FC will balance the thrust.

Although its not going to be perfect as it would have been with all motors same.

Hi Veergamer,

You've got two answers, one says no, other says maybe, and if you ask me the answer would be no ( sorry Saurabh sir ) and here is the 'why' behind the answer.

Quads are simple systems in terms of construction, its basically an X with a motor propeller pair strapped to each end. But they are fairly complex when you look at the dynamics of this system. These motors swing props, which in-turn moves each arm of the quad linearly. this linear motion causes a change in the angular momentum of the system, which is what the FCs measure to keep the system stable. Theoretically, if all the arms are moving with the same velocity, the quad is stable.

Now take these motors, their KV rating essentially translates to the number of rotations per minute they are going to shell out for every volt of electricity flowing through them. So looking at your case, the motors with 2700 KV will be moving at higher RPMs for the same voltage provided across all four motors, that means the propeller strapped to this motor will be generating more thrust then the rest three, and thus more lift causing faster linear motion along that axis.

This difference in lift can be managed by the FCs, and that's pretty much what they do most of the time to make your quad stable, but since these are high KV motors, they will be swinging 5 or 6 inch props with a somewhat square pitch, the overall change in the angular momentum created by  the rapid change in the rpm of the motor, while the FC is trying to compensate for the extra lift will quickly throw the quad into a deadly oscillation. and that's a bad bad thing.

Hence either get 4 identical motors, or rewind the 2700 KV motor for 2300 KV ( that's a lesson for some other day )

Keep asking

Very well explained Bilal sir ....thanks for sharing

@arorasoham9  ohh no 'Sir' pal, am not knighted yet :-p

Thank you everyone for explaining. I've started my search for 2300kV motors again will mKe my quad with 4 2300kV motors as soon as i find one.

Best Regards

Hello Bilal,

Long time no update !!!... hope you are still flying on.

I completely agree what you have mentioned above. I also did mention that different KV motors will not be a perfect scene. But i have experience with NAZA that the FC can control thrust to a much greater extend +- 50%.

ref. to 7 Min at this video....https://www.ted.com/talks/raffaello_d_andrea_the_astounding_athletic_power_of_quadcopters

(2 different motors )

A trial can be done.

Beginner --> NO 
Experts --> not a bad idea to give it a shot.

Correct me if i am  wrong but won't this affect the maneuverability of the craft?

Yes it will.....Ideally all motor should be same. Any change will bring in change in maneuvers.

It can be done for trial.... Not proper flying.

Hello guys,
I think using two different motors may work out.

Let us assume a quad with 3 2204 2700KV and 1 1806 2300KV motors. To maintain a desired attitude(let's assume a hover), all that the flight controller can do is increase/decrease each motor's speed.

Now, each esc-motor-prop setup has its own reaction time to the command from the FC. Clearly, 1806 is going to be reacting slower than the others. The FC is simply going to increase the 1806's speed for it to keep up with the other motors.

Expected behaviour:
-On a quick throttle up or flip, you may feel a dip on 1806's arm due to this.
- The lower power motor is going to limit the performance of the entire system. Because the FC cannot push the three powerful motors to their maximum, simply because the less powerful motor  cannot keep up with them. The 1806 will max out easily than the rest. The PID cannot be optimal on any axis.
- If the less powerful motor is placed on the right arm, left roll(which needs right motors to max out) is going to be slower than a right roll.

Suggestion:
- If you will cruising for the most part, place the less powerful motor on a front arm because in a typical forward flight, back motors do marginally higher work.
[My wildest thought is to use a different prop with 1806 to compensate, but yes I do understand the practicality].

Links:
You are not alone. Check these links:
https://flitetest.com/articles/quad-copter-with-different-sized-motors





https://www.rcgroups.com/forums/showthread.php?2419871-what-are-the-odds-of-using-diffrent-brand-but-size-motors-on-same-quadcopter

My opinion:
If we are talking about 3 dys 1806 2300KV and 1 dys 1806 2700kv, give it a try.
If the setup has different stator sizes and different KVs, take your call but I would suggest that you still try.

Of course it is not going to be as smooth as a uniform setup. But, will it fly? Considering high FC loop times, I think it would(I never tried though).

Quote from: rastsaurabh on March 12, 2017, 12:08:13 PM

It can be done for trial.... Not proper flying.

I agree

Sent from my CP8676_I02 using Tapatalk

So.... who is trying....?? Keep us updated.

I will do it but will take some time as I am in process of making a Quad.

What will happen if we use 2 different motors mounted diagonally opposite to each other?

Guys I'm tryibg this on my own, I dont have much experience with quad as this is my first one but listening to you all I got an idea and am going to execute it.
Will keep you posted about it and may need your help.

Best regard

Its good to experiment .... Veer.

But note that before experimenting ensure your quad is flying properly with all things normal.

this way you would be able to diagnose the effect of your experiment.

All the best !!

What do you suggest about using one 2280kV motor with 3 2300kv motors?
I believe it should work almost equally as same 2300kV 4 motors would

Ideally no issues