I need help to fix my drone.
I have build Arduino , nrf24 brushed drone based on this tutorial ( Brushed motors Arduino cheap homemade drone )
The problem is that the drone doesn't fly. Based on my troubleshooting the top left motor is not spinning as fast as the other causing the drone to SPIN and flip when I try to take off. I have given the images of the drone and the video , showing the problem.
images:-
File sharing and storage made simple
File sharing and storage made simple
File sharing and storage made simple
video:-
https://www.mediafire.com/file/al8cbyrulzxsgum/VID_20210323_155839%25280%2529.mp4/file
Hi,
It is hard to tell from your video, have you checked the direction of rotation of the motors, as per the image from the instructions.
And you do have the correct props on the correct motors?
Do you have a DMM to prove that the suspect motor is being supplied less power?
I also notice you have three motors with black and red wires and one with blue and red, is the blue and red wired motor the suspected unit?
Thanks.. Tom... 
Hi,
I'm not sure but there appears to be an anomaly
.
Even though in the Electronoobs video he has them configured direction wise as described in the image.
Tom...
Within limits, the flight control software can compensate for motor differences.
But you may just have a bad/weak motor. Does the problem change if you swap motors around, paying attention natch to CCW and CW?
Or a bad/weak motor driver, have you swapped those around?
Did you perform the Java IMU test (?) and see if your received values are plausible as advised?
Even when everything is 100 percent correct, a quad might still freak out or otherwise be unflyable. Is adjustment of the flight control software covered in your tutorial guide? Have you experimented with that?
Also, this quadcopter is on the very edge of flyable as it is. A single lipo cell, kinda big and heavy… if it ever does fly, it's not going to be much fun other than the satisfaction of making it function.
Edit: the OP's propeller picture looks correct. See the orientation of the legend on the props. Doesn't mean they are spinning in the right direction, doesn't mean the flight control software wants the standard motor directions, could be exactly the opposite.
a7
One motor stopped working and i replaced that motor only . that is why 1 motor wire color is different.
The motor model is same. i have tried swapping the motors and the problem still exists that the drone spins to one side.
Thanks you for replying.
Pulling teeth mode.
Have you confirmed and verified that the motors are spinning in the correct directions and have the correct peopeller each?
What is the circuit supplying current to the motor? Are all four instances functioning correctly?
a7
Hi,
Are you sure that two of the motors is spinning in opposite direction to the other two and that they have the correct prop fitted.
If you fix the drone to the table and operate it, when you put your hand under each motor do you feel a downward flow of air?
Is your IMU oriented in the same direction as the instructions.
Tom...
PS. @alto777 great minds think alike, pity that us fools never differ...
Yes the motors are spinning in the correct direction and props are also placed in correct position. I can also feel air is flowing downloads when i put my hand under the drone.
You still have not answered the questions we've asked, believe it or not we trying to help.
In the meantime:
Attach a large-ish weigh to the base of the quadcopter.
Start it up and gently raise the throttle a bit.
The aileron stick should be able to make the quad tilt to the left and right.
The elevator stick should be able to make the quad tilt forward and backward.
The rudder stick should make the quad try to twist left and right.
The throttle stick should make the motors go faster and slower smoothly.
---> The weigh should be heavy enuf to keep the quad from lifting off or flipping over.
If your quad cannot perform this test, it is pointless to try flying it witouth the weigh holding it back.
Are you using stabilised control loops or attempting a simpler "acro" control mode?
If your quad passes this test, I'm out of ideas just now.
a7
I have done the test and everything works . I have noticed that when I give throttle rear left motor and front right motor starts first and them the other two motors start. Is it normal to have like that? and it looks like rear left and front right motors are spinning faster than other two. I found this when I tried giving roll left and right. When tilting left and right these two motors(Rear L and Front R) doesn't completely stops it only slows down the speed while the other two motors stop completely.im new to this so I fully don't know which modes I'm a using . I have enabled horizon
mode in multiwii config application
Hi,
This is where you need to write some simple Tx and Rx code to JUST operate each motor independently so you can diagnose if it is a hardware or powersupply or software problem.
Forget for the moment trying to fly, forget for the moment the IMU.
DO YOU HAVE A DMM?
Thanks.. Tom...
yes I have a digital multimeter.
The physical design of motors with carbon brushes makes it impossible for such motors to have the same power/speed when rotated in opposite directions.
Paul
Which is why usually 2 motors are black & white and spin one way, 2 motors are red and blue and spin the other way.
Ppl do run them backwards, however, in 3D flight modes.
It may be that the flight control software can compensate for unequal, whatever the reason be, motors. 3D usually involves reversing all four motors, however, so using one motor incorrectly might break the deal.
Still feels like something essential wrong in the setup. I agree that some examination of basics as @TomGeorge outlines is in order.
a7
alto777:
Which is why usually 2 motors are black & white and spin one way, 2 motors are red and blue and spin the other way.Ppl do run them backwards, however, in 3D flight modes.
It may be that the flight control software can compensate for unequal, whatever the reason be, motors. 3D usually involves reversing all four motors, however, so using one motor incorrectly might break the deal.
Still feels like something essential wrong in the setup. I agree that some examination of basics as @TomGeorge outlines is in order.
a7
Correct! The brushes a physically biased/positioned to favor one direction. They are NOT centered exactly on the rotor axis.
Paul
Hi,
Thanks @Paul_KD7HB and @alto777, I'm not an expert in drone motors.
Can you please post a link to where you bought the motors please?
Thanks.. Tom..
First I bought from this link ( https://a.aliexpress.com/_mO8fjjd ) and when I was testing the drone I broke one of the motors and I bought another set of motors from amazon ( https://www.amazon.in/dp/B07MCPLRPW?ref=ppx_pop_mob_ap_share )
Hi,
Did you get two different pairs in your order from Amazon?
The colour of the wires distinguishes the pairs and as @Paul_KD7HB and @alto777 confirm the are motors that only perform properly if driven in the correct direction.
You should have 2x CW and 2x CCW motors.
This picture shows you have 3 of one direction and 1 of the other direction.
That is 3 black and red wired motors and one blue and red wired motor.
Tom...
The motors I got from amazon has all same motor wire color ( red and blue). Same goes for the Ali express motor except the color of all motor wire is red and black . is there any way to know if they are CW or CWW.
thanks.