Taranis XD-9 motor sync issues

[Brainscum]

After taking a couple of abrupt falls with my zmr250 (naze32 board.) I went into cleanflight to see if I could diagnose the problem. In cleanflight when I test the motor calibration all motors run together in perfect sync. However when I check the motors through my TXD-9 two of the motors will sync up and the other two fidget and just stop periodically (mostly at low throttle.) Has anyone ever heard of this? Should I replace the motors or do something inside the Taranis?

 

[Talon Six]

I'm running the same setup, so let's check a couple of settings. First thing's first - take your props off.

Start the Cleanflight Configurator and connect your Naze to the computer.
Next, with your Taranis on and your ZMR powered up, go to the Receiver tab on the Cleanflight Configurator. You should be able to see the PWM inputs change as you move the controls on your Taranis.
Q: What is the reading on the Throttle channel with the throttle all the way low?

Next go to the Configuration tab.
Q: What are the numbers for Minimum Throttle, Max Throttle, and Minimum Command?

 

[Sudovoodoo80]

A esc calibration usually solves this kind of issue, or at least is the first thing I would try.

 

[Brainscum]

I'm running the same setup, so let's check a couple of settings. First thing's first - take your props off.

Start the Cleanflight Configurator and connect your Naze to the computer.
Next, with your Taranis on and your ZMR powered up, go to the Receiver tab on the Cleanflight Configurator. You should be able to see the PWM inputs change as you move the controls on your Taranis.
Q: What is the reading on the Throttle channel with the throttle all the way low?

Next go to the Configuration tab.
Q: What are the numbers for Minimum Throttle, Max Throttle, and Minimum Command?

Hey Talon Six,

In the Receiver tab with the throttle all the way down it reads 993. The motors begin to spin at 1127 but that is only motors 3 and 4. Motor 2 begins to spin at 1212 and motor 1 begins to spin at 1357.

Over in the Configuration tab the minimum throttle is set to 1000, the max is set to 1850, and the minimum command is set to 1000.

 

[Brainscum]

A esc calibration usually solves this kind of issue, or at least is the first thing I would try.

Thanks Sudovoodo80,

That was the first thing I tried with the same theory that the esc's just need calibrated. They calibrate and fire up in cleanflight fine as long as I'm controlling them through the app. It's when I give the copter throttle through the Taranis that they start up out of sync. So I'm now staring to think the issue might be in the transmitter or receiver but I don't have enough experience to troubleshoot those.

 

[Talon Six]

Hey Talon Six,

In the Receiver tab with the throttle all the way down it reads 993. The motors begin to spin at 1127 but that is only motors 3 and 4. Motor 2 begins to spin at 1212 and motor 1 begins to spin at 1357.

Over in the Configuration tab the minimum throttle is set to 1000, the max is set to 1850, and the minimum command is set to 1000.

Okay we're making progress. Can you post a picture of your connections from the ESCs to your Naze32?

 

[Sudovoodoo80]

Also post a list of parts please, we know naze32, what motors, esc's, receiver are you using? Is there a PDB?

 

[Brainscum]

Okay we're making progress. Can you post a picture of your connections from the ESCs to your Naze32?

Here's my Naze32 board. All of the connections seem to be tight. I'm running ppm to the receiver. The receiver is undamaged, I have it mounted just below the Naze32. The escs are afro 12a connected to dys 1806-2300kv motors.

 

[Talon Six]

I see a couple of issues (and Sudovoodoo please feel free to chime in here as well).

First off, do you have pins 3 and 4 jumpered on your D4R? You need those to run in CPPM mode. I can't tell because the servo wire from ESC 1 is covering it up.

Second, you're running power to the Naze 32 from too many places. You've got 5v coming off each ESC's BEC and you've also got something running into the VBAT. So your board has a total of five power sources and grounds hitting it, which I believe is a major part of your problem.

You only need one 5v source running into the board. Mine receives power into the VBAT from an OSDoge (stackable OSD). The OSDoge is connected to the main flight battery. I only have the signal wire from each ESC connected to the motor outputs; I believe this is the recommended Naze32 setup. You can test this by removing the power and ground wires from all your ESCs (make sure they don't touch!) leaving only the signal wires going into the Naze. Just take a small flat tip screwdriver and carefully pry the retaining plastic tabs on each of the ESC servo leads to remove the power and ground. Then put a piece of electrical tape around the exposed lead to keep it from shorting. Re-calibrate your ESCs in the Configurator and see if this doesn't solve your problem.

An alternative would be for you to disconnect all but one of the ground and power wires from your ESCs, so you'd only have signal going into three of the four ESCs. You will also need to disconnect the VBAT for this option. What this does is reduce the number of power sources going into your board to one (which is what you want), but it eliminates the ability of your board to monitor your battery voltage.

The last issue I see, which is minor compared to the power issue, is your wiring needs cleaning up. All that extra wire can attract and or generate interference. A servo crimping tool can make life much easier.

Let us know if these steps work.

 

[Sudovoodoo80]

I don't think the naze rev 5 can run only on power from the Vbat. Vbat should be full battery power for battery monitoring purposes, but does not power the 5v side of the board , there is no bec on the rev 5 naze board (Talon you may be thinking of a f3 board like the dodo, where full battery power can be applied to run the board). But otherwise correct. Those are afro esc's, right? I think they have a linear bec, so running more than one power and ground wire shouldn't hurt anything (with switching bec's it would), but best practice is to run power from only one esc, leaving only signal on the rest (some say that signal and grond but no power should be used, this is what i generally do). You don't have to cut the wires, just remove the power connection from three of the jst plugs and heat shrink them or wrap them in black tape, if you think you might want to use them later. Also I am assuming you are testing the motors without props on the bench, and that is where you are seeing this unusual motor behavior? It is possible that the board is responding to lack of feedback from the sensors and causing this strange behavior. What flight mode are you in while testing? Is there any difference in behavior if you change flight modes? How about if you move the quad, do the other motors start? Have you flown it, and if so is there any difference in behavior with the props on, and does it seem to affect flight or only when testing? I have run this exact same setup before, same motors and esc and flight controller. I'm guessing you did this build following Bruce's instructions from RCModelReviews? Aside from the pile of wire, your connections all look correct, but double check the solders and wires from the receiver to the board to be sure that you have good solid connections, if possible hit them with a multimeter to make sure you get good connection from the solder blob to the connector on the servo end. Also like talon said, make sure the jumper is in place and firmly seated. Only other thing is the way you have those esc's mounted on the arms is bound to be restricting air flow, just use a small strip of heat shrink instead of covering the whole esc, that way they will stay nice and cool and happy.