M1 on KK2.1.5 Won't Work-How to Use Only M2-M5

Zorb

Junior Member
Hello everyone, I'm new here and this is my first post.

So I'm building my first quadcopter and have run into a problem. When I power it on any motor/ESC combo that's connected to channel M1 does not work properly. It will twitch randomly and when I give the quad some throttle and then take it off any motor connected to M1 will keep spinning for a while.

I've made sure all the connections are secure. I've reset the board done ACC calibration and have calibrate the ESCs with the TX. The problem still persists.

From reading around I've seen some people mention only connecting motors to M2-M5 and using a BEC on M1 for power. I can't find anywhere how this is done. I think this would be the easiest solution. If anyone knows how to do it please let me know or if there are instructions somewhere that also work.

Any suggestions are greatly appreciated.

Thanks
 

cranialrectosis

Faster than a speeding face plant!
Mentor
Is the prop loose?

If not, jittery motors are most often caused by a bad connection where the motor leads are soldered to the ESC. Most often this is due to enamel on the motor leads. If you have enamel on your motor leads you need to burn it off before you attempt to tin your wires.

The motor spinning for a while after shut down is what is really throwing me here. It almost sounds like a bad ESC flash. I would move your M1 ESC to another boom and see if the problem moves with the ESC. If the problem goes away completely you fixed it when you re-soldered the motor leads.


On a KK2 you power the board by providing 5V and ground to one of the motor pins or the receiver pins. There are two separate circuits on the KK2. Most people provide power to a KK2 by connecting M1 power and ground to 5V.

Where you get the 5V is up to you. If your ESCs have BECs, that's 5V right there. When you connect M1 signal from the ESC just connect to power and ground from the same ESC. If your ESCs do not have BECs, use a 5V step down Pololu like this one for a quad. If you build a tri-copter you may need to bump up to a 1A regulator such as this one to support a tail servo.



If none of this works, do not despair. Post a short video clip of the thing acting up and let's take another look. If these things were easy, they wouldn't be nearly as cool. :)

Welcome to FliteTest!
 

Zorb

Junior Member
Hey thanks for the reply.

I've checked and resoldered all the connections and they all seem to be fine. The problem does not appear to be with any motor or ESC it's solely on the M1 connection. Any motor or ESC that's connected on M1 is where the problem is. I've tried changing all the settings around and nothing fixes it. I've seen other people with the problem and they increase height dampening to fix the problem. This doesn't work for me. Also when you give the motors throttle any motor and ESC combo on M1 keeps spinning after I let go of the throttle.
 

cranialrectosis

Faster than a speeding face plant!
Mentor
It's been several (3?) years since I have used a KK2 and I don't have any any longer to play with.

At this point, I would swap out the board.

However, since you had questions about powering the KK2, it may be worthwhile to investigate how you are powering the KK2 to eliminate that as a potential cause and hope CraftyDan who still flies KK2 chimes in with better suggestions.

How do you power your KK2?
 

Zorb

Junior Member
I have a 3s lipo connected to a PDB with a BEC and it can output 12v. Then I just connect the ESC cables to the kk2.1. 5 and everything seems to power on fine.

Also, not sure if this is normal but I've read that the KK2.1. 5 gets power from the M1 connection but if everything is disconnected and there's only a connection on M2-M8 everything still powers up.
 

cranialrectosis

Faster than a speeding face plant!
Mentor
It is normal. :)

You can power the KK2 from any motor pin but M1 is most common. You are powering your KK2 when you connect the power and ground wires from the ESC to M1 along with the signal wire. Most likely you are connecting all 4 ESCs this way meaning you are sending 5V power to the KK2 from all your ESCs. I built my first 4 copters the same way with no problems.

I am wondering if you have an ESC shorting out the signal wire, but if it were me at this point, I would swap out the KK2.