motors not starting in sync and rpm not the same

Cory kaufman

New member
So I’m relatively new to this hobby but I’m having a blast with it and I got the tiny trainer and it flys great and I’ve got a couple other planes I’ve built to and was starting to put electronics in and setting them up for whenever I feel I’m skilled enough to fly them and the specific one I am having trouble with is the a-10 it is an amazing plane and I have followed all the setup steps in their build video and triple checked the settings but one of the motors starts up later than the other and doesn’t have as much thrust as the other along with neither of them start up till sometime after 50% throttle also the differential thrust on them won’t work also the ailerons are not staying in their default positions after I move them I have a video too better show the issue but I can’t post it on here that I can find ,thanks.

(I have also tried using different batteries and motors to make sure there was no faulty equipment)
 

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Burnhard

Well-known member
It sounds a bit like your ESCs might not be properly calibrated. Try to recalibrate the ESCs. If the issue prevails you should try swapping the ESCs for other ones.
 

Mr NCT

Site Moderator
So I’m relatively new to this hobby but I’m having a blast with it and I got the tiny trainer and it flys great and I’ve got a couple other planes I’ve built to and was starting to put electronics in and setting them up for whenever I feel I’m skilled enough to fly them and the specific one I am having trouble with is the a-10 it is an amazing plane and I have followed all the setup steps in their build video and triple checked the settings but one of the motors starts up later than the other and doesn’t have as much thrust as the other along with neither of them start up till sometime after 50% throttle also the differential thrust on them won’t work also the ailerons are not staying in their default positions after I move them I have a video too better show the issue but I can’t post it on here that I can find ,thanks.

(I have also tried using different batteries and motors to make sure there was no faulty equipment)
Do you have the transmitter set up for differential thrust? If not, then I am with @Burnhard.
To calibrate the ESC‘s first take off the props. Disconnect the battery.
Turn on the transmitter and put the throttle to full.
Then plug in the battery on the plane and you should hear a series of beeps.
After you hear the beeps pull the throttle back to zero and you should hear some more beeps.
The ESC’s are now calibrated.
 

quorneng

Master member
If you want to post a video you have to download it onto a host site like YouTube.
One there you can then use the link icon to add the YouTube URL of your video to your post.
 

Cory kaufman

New member
Alright I’ll try it thanks
That helped but the right motor is still kicking on before the left but I believe it’s cause the gear is set up to start slightly later than the other also the left once it has started up is stronger than the right one do you happen to know how to fix that

(My gear and throttle are mixed)
 

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Mr NCT

Site Moderator
That helped but the right motor is still kicking on before the left but I believe it’s cause the gear is set up to start slightly later than the other also the left once it has started up is stronger than the right one do you happen to know how to fix that

(My gear and throttle are mixed)
Are you using a Y connector to connect both ESCs to the throttle plug on your receiver?
 

Burnhard

Well-known member
That helped but the right motor is still kicking on before the left but I believe it’s cause the gear is set up to start slightly later than the other also the left once it has started up is stronger than the right one do you happen to know how to fix that

(My gear and throttle are mixed)
Gear and throttle mixed? That sounds wild. Just out of curiosity, how is this supposed to work?
 

Burnhard

Well-known member
Most of the other ports on the receiver are being used so if you use the gear port and mix it with the throttle they work in sync if I’m correct?
Just for my understanding, on your receiver you have a y cable for the throttle port that is connected to your motor and landing gear? Or is it that you have the one motor on the throttle port and the second motor on channel 5 (the gear port)? If it is the latter, instead of mixing, can’t you set up the throttle stick for channel 5 directly?
 

Mr NCT

Site Moderator
If you get a Y servo connector you can use only one port. Remember you need to take a red wire off the connector on one of the servo cables coming from one of the ESC's.
 

WillL84

Active member
If you get a Y servo connector you can use only one port. Remember you need to take a red wire off the connector on one of the servo cables coming from one of the ESC's.
Why this? I used a Y splitter for the ESC's on my Legacy and just plugged them right in
 

Mr NCT

Site Moderator
Why this? I used a Y splitter for the ESC's on my Legacy and just plugged them right in
Rumor has it that using two voltage supplies to the receiver can cause problems - each ESC is supplying power. I have not tested it myself but that is the accepted wisdom.
 

quorneng

Master member
It depends on the BEC in the ESC.
If it is a linear BEC then 2 ,or more, ESCs can be on a Y lead without disconnecting the red wires. However the ESCs will not share the load equally depending on their manufacturing tolerance so don't assume to maximum load is sum of the individual BECs.
More modern ESCs now use the more efficient (don't get so hot) switching BECs. As these send on/off pulses of power to the load. It is important to only have one switched BEC suppling all power to ensure accurate voltage control..
 
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WillL84

Active member
Rumor has it that using two voltage supplies to the receiver can cause problems - each ESC is supplying power. I have not tested it myself but that is the accepted wisdom.
Interesting. FT never said to do this in their build video for it. I think they hooked theirs up for differential thrust too though. They did connect it with a Y cable to setting up the rotation directions:


Actually at 31:38 he does say if you don't want to use differential thrust to just wire them together.
 

Mr NCT

Site Moderator
Interesting. FT never said to do this in their build video for it. I think they hooked theirs up for differential thrust too though. They did connect it with a Y cable to setting up the rotation directions:


Actually at 31:38 he does say if you don't want to use differential thrust to just wire them together.
I haven’t tested it to see for myself. It may be “popular wisdom” like always extending the motor wires rather than the battery wires, but it’s easy enough to do.