Solved I need help setting up my FT Dart!

[Flying Oscar]

Hello, a few months ago I bought the FT Dart as my first flite test plane. I built all the foam and electronics for it, but have not been able to set it up with my transmitter. I have been using a Y cable since I am just starting out, and my transmitter is the TGY 9x (it was cheap and has very poor documentation). The flaps work perfectly, but when I try to throttle up the motors they spin at different speeds, and then their speeds switch! Does anyone have any idea of what might cause this? It makes no sense to me and I would be extremely grateful for any help you people can offer.
Thanks!

 

[d8veh]

Most likely, you need to calibrate the ESCs. Disconnect one, while you calibrate tge other. The normal procedure id to switch on your Tx and push the throttle to fully open, then switch on the Rx. After a few seconds, you should hear a couple of beepsfrom the ESC. Put your throttle back to fully closed and you should hear more beeps and then the initialisation beeps. Repeat for the other ESC.

Which ESCs do you have? Do the motors work OK other thanthe different speeds?

Another important thing is that you cannot connect the two receiver cables from the ESC with a Y-lead without removing one of the 5v wires (brown or red) otherwise you get all sorts of strange things happening. So, in the Y-lead, you have 2 blacks into one, two signal wires into one, but only one 5v into one. It doesn't matter wich one you pull out or cut.

 

[Flying Oscar]

I have the Emax 12a Bullet ESC's that came with the power pack H, and I tested the motors which work fine. Also, the signal wires to the ESC's only have two wires, so is that what you're talking about?
I followed your procedure to calibrate the ESC's but I still had the same results... Is it possible that they are damaged, or something is wrong with my transmitter/receiver?

 

[DamoRC]

If your motors are running (albeit at different speeds) in response to the throttle, and they are both connected through a Y-connector to the throttle channel on your receiver, then it is unlikely to be your Tx / Rx. I would suggest trying to calibrate both together at the same time (props off for safety). Then check to see if your motors are running at the same speed with the props off. If this works, then put the props on and check again making sure you have the props on the right way around and that the motor is spinning the correct way for the installed prop (its possible if one prop was on backwards, or if the motor was turning the wrong way for the installed prop, the motors would run at different speeds because the loads on the motors are different).

DamoRC

 

[Flying Oscar]

If your motors are running (albeit at different speeds) in response to the throttle, and they are both connected through a Y-connector to the throttle channel on your receiver, then it is unlikely to be your Tx / Rx. I would suggest trying to calibrate both together at the same time (props off for safety). Then check to see if your motors are running at the same speed with the props off. If this works, then put the props on and check again making sure you have the props on the right way around and that the motor is spinning the correct way for the installed prop (its possible if one prop was on backward, or if the motor was turning the wrong way for the installed prop, the motors would run at different speeds because the loads on the motors are different).

DamoRC

Hmm... I will try that. Just to clarify to everyone, as I smoothly move the stick it starts with one prop pushing more than the other, then halfway through the other prop starts pushing more than the first prop, which is really what confuses me.
Thanks!

 

[DamoRC]

Hmm... I will try that. Just to clarify to everyone, as I smoothly move the stick it starts with one prop pushing more than the other, then halfway through the other prop starts pushing more than the first prop, which is really what confuses me.
Thanks!

If one of the ESCs was really off on calibration this could happen but it does sound a little weird. Best to ensure that the calibrations are set for both ESCs and that the props are correctly installed based on the rotation of the motor. If it is still happening we can move onto the next line of troubleshooting.

Can you post pics of your setup (the motors, ESCs, and power distribution board laid out)?

DamoRC

 

[d8veh]

It wouldn't surprise me if one of the ESCs is faulty. One last thing to check is the timing.
https://dronebuildersblog.wordpress.com/2016/01/10/emax-blheli-brushless-esc-programming/

 

[Flying Oscar]

I ran the tests you guys suggested, and also tested each motor individually. The props and motors were correct, and calibrating the ESC's at the same time didn't change anything. However, when I tested the throttle with one of the motors, the motor got to full speed halfway through then drops down to its minimum speed and then speeds up again as I smoothly move the stick. The other motor, however, spins perfectly as expected! This means that only one ESC is actually problematic, but I still don't understand what might be wrong with it.

I have attached some pictures, but when I was building the plane a couple months back I closed up the wings with the ESCs before testing everything.

 

[Flying Oscar]

Just an update, I will also try to set up differential thrust once I learn to fly it with a Y cable, and I will probably need help with that, but it will definitely have to wait until I fix the faulty ESC. Speaking of which, is the ESC a problem I can fix or will I have to replace it?

 

[Merv]

the motor got to full speed halfway through then drops down to its minimum speed and then speeds up again

To me sounds like you have the model in the Tx on the default Helli mode. Try a new setting up a new module in your Tx, the first thing you need to do is select airplane mode.

 

[Flying Oscar]

To me sounds like you have the model in the Tx on the default Helli mode. Try a new setting up a new module in your Tx, the first thing you need to do is select airplane mode.

Thanks for responding, but I have been sure to double check all the settings (not all of which I can understand, but...) and I am using an airplane model. Also, I was using a Y cable and the other motor worked perfectly fine from the same output.

 

[reburg99]

To isolate the issue to a faulty ESC, try swapping the escs between motors. If the problem moves with the ESC, then that's pointing towards and issue with the ESC or connections to the ESC. If the problems remain constant I would lean towards an issue with the motor.

 

[d8veh]

To isolate the issue to a faulty ESC, try swapping the escs between motors. If the problem moves with the ESC, then that's pointing towards and issue with the ESC or connections to the ESC. If the problems remain constant I would lean towards an issue with the motor.

I think they're built into his wing with no access.

 

[reburg99]

I think they're built into his wing with no access.

If that's the case, then he can swap the motors. This should have the same effect as swapping the ESCs.

 

[Flying Oscar]

If that's the case, then he can swap the motors. This should have the same effect as swapping the ESCs.

Ok, I will try that. They are kind of built in too, but I can make do with the fact that the wiring is partially on the outside.
Note to future self... ACTUALLY make sure all the wiring works before closing up the plane!!!
If it turns out the one or the ESCs is actually faulty, not the motor, should I just get a replacement?

 

[reburg99]

Depending on how long you've had it, might be able to do a return for a replacement.

 

[Flying Oscar]

Depending on how long you've had it, might be able to do a return for a replacement.

I've had it since mid-July. Also, I have confirmed that the ESC is the problem, not the motor. I searched the store and they don't actually sell it by itself. Would a different 12a ESC work? Or would mixing and matching be a bad idea?
EDIT: Is this more or less the same one?

 

[d8veh]

Good question. My instinct says that it would be better to have identical ESCs,, but if they have the same firmware (Bheli/Simon K), they should behave the same.

 

[Merv]

Would a different 12a ESC work? Or would mixing and matching be a bad idea?

With planes ESC are not that critical. I would not be afraid to mix similar ESC. I would not mix a high ens ESC with a cheap one. With quads, the ESC need to be higher end and should be identical.

 

[Flying Oscar]

Well, I'm pretty sure the only difference between the one I have and the one I linked is that the one I linked comes with connectors and shrink wrap and has a BEC. Does that sound like they are similar enough?
Edit: I think this is actually the exact same thing.