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I need help with duel motor synchronization

#1
I am building a plane for the first time and all of my electronics work properly. I have two esc's each with their own 11.7v battery (2200mAh) which are each connected to one motor like usual. I then have the two JR plugs which go into a Y-harness and go into my one single throttle channel port. For some reason though when I start raising the throttle, the first motor kicks on instantly as it should but the other motor doesn't turn on until i get to about 10%-25% throttle. I don't know why it does this and I tried calibrating the esc's but I don't know if there is some special way to do it with two motors.
20200228_102325.jpg
20200228_102325.jpg

Specs
-Transmitter: FlySky FS-i6X
-Reciever: Flysky iA10B 10CH Receiver
-Motors(2): A2212/6t, 2200kv
-Esc's(2): 30A esc's which came with motor
-Batteries(2): Ovonic 11.1V 2200mAh 3S 50C Lipo Battery
20200228_102325.jpg
 

Brett_N

Well-known member
#2
The ESC's don't "ARM" at the same time because you have to plug two batteries in.

Here's the trick.

1 - Remove one of the RED wires from ONE of the ESC harnesses BEFORE it goes into the Y-adapter. (you can gently pull up the little black tab and the connector will pull straight out)

2 - Get a Y-adapter for your ESC battery connections so that you only use 1 battery.

This way when you plug in, both ESC's arm at the same time when doing the throttle calibration (sticks up, plug in, wait for beeps, etc.)
 

Wildthing

Well-known member
#3
Only calibrate one esc at a time, unplug one while you calibrate the other. Also depending on the esc remove one power lead going to the rx before the Y, you only need power from one esc feeding the rx.

The other thing I would do if you are planning on running dual batteries make yourself a H connector so both motors are running off of both batteries at the same time. The reason is if one battery dies before the other you are in trouble with only one motor working.
 

herbertjalarcon

Well-known member
#4
I have several twin engines and I learned the trick...works everytime... Turn the transmitter on first, arm the motor and turn the throttle all the way up...set the trim in the middle...not all the way down...Then, plug in the batteries as fast as possible (I only use one larger battery)...this should trip the safety switch (be careful the first time, but the motors should NOT start), then pull the throttle all the way back...this will turn off the safety switch and arm the ESC's at exactly the same time...I do this at least 10 times every time I fly, and it works! I would suggest one battery for ease...
 

herbertjalarcon

Well-known member
#5
I have several twin engines and I learned the trick...works everytime... Turn the transmitter on first, arm the motor and turn the throttle all the way up...set the trim in the middle...not all the way down...Then, plug in the batteries as fast as possible (I only use one larger battery)...this should trip the safety switch (be careful the first time, but the motors should NOT start), then pull the throttle all the way back...this will turn off the safety switch and arm the ESC's at exactly the same time...I do this at least 10 times every time I fly, and it works! I would suggest one battery for ease...
I have done the same trick with two batteries as well...
 

Merv

Well-known member
#6
I agree with both @Brett_N and @Wildthing.

Either calibrate the ESC's one at a time OR plug them in at the same time, a Y harness from the battery. The time difference from plugging them in one at a time is messing up your calibration.

You only want use one BEC at a time, unplug one of the red wires from the Y harness or BEC. If both are connected, they end up fighting each other, one will call for slightly higher voltage and one slightly lower.
 

herbertjalarcon

Well-known member
#7
I agree with both @Brett_N and @Wildthing.

Either calibrate the ESC's one at a time OR plug them in at the same time, a Y harness from the battery. The time difference from plugging them in one at a time is messing up your calibration.

You only want use one BEC at a time, unplug one of the red wires from the Y harness or BEC. If both are connected, they end up fighting each other, one will call for slightly higher voltage and one slightly lower.
I have found even on a y harness for the batteries, the ESCs will not "fire up" at the same time...my trick fires them at exactly the same time...works on differential thrust as well...
 

Wildthing

Well-known member
#8
Well if both are calibrated the same it shouldn't matter if one initializes slightly faster then the other, both motors should react the same for the throttle signal.
 

herbertjalarcon

Well-known member
#9
Well if both are calibrated the same it shouldn't matter if one initializes slightly faster then the other, both motors should react the same for the throttle signal.
I agree, but that has not been my experience...it's really noticeable when you set up differential thrust...the Super Bee will turn if you punch it without syncing the ESCs...but again, just my experience...I think it has to do with resistance withing the electronics...
 

Wildthing

Well-known member
#10
I agree, but that has not been my experience...it's really noticeable when you set up differential thrust...the Super Bee will turn if you punch it without syncing the ESCs...but again, just my experience...I think it has to do with resistance withing the electronics...
Well you do require matching components and even then that isn't a guarantee, you could have one motor that is slightly lazy compared to the other. With twins I will always do a vertical thrust test to make sure the plane lifts straight before I even attempt launching it.