Quad does not always arm...

[tomb18]

Hi,
I have a problem which occurs roughly 50% of the time or more. When I power on my quad, and then link my transmitter (after waiting for led lights to be appropriate), when I arm the quad (both sticks to lower left) it may or may not start the motors. This happens about 1 in two or sometimes more times.
If I power off and try again, it might work. Eventually it will work and then all seems OK.
When it doesn't work, the transmitter and receiver are linked, the Naza LED will flash appropriately when controls are centered and flash propery when not. Also, if I switch to failsafe, the LED will flash telling me it is in failsafe mode. So All seems to be working except the motor / esc setup.
Frame Tarot 650
NAZA M V2 FW 4.01
Radio FUTABA SG14 + F7008SB in sbus or normal mode makes no difference
Motors SunnySky X4108S 600kV
ESC's RangeVideo 40A Opto (with SIMON firmware).
4S battery. All voltages are correct from PMU, to ESC's etc.
Thanks, Tom

 

[Motopreserve]

First, make sure you always turn on the transmitter first.

But it sounds like this may be an issue of the sticks not being calibrated. Have you done the stick cal in the Naza assistant? Before you do, make sure the sub-trims are all centered.

Have you done a throttle/esc calibration?

 

[tomb18]

Hi,
Yes a stick calibration was done as well as the throttle/ESC calibration. Several times in fact.
However, I did not always have the transmitter on first....I'll need to look at this more. Is this recommended? I have come from an openpilot controller previously, and you usually turn on the quad first.
Thanks

 

[tomb18]

Ok, it seems I now can get this to work all the time. It has to do with the transmitter being on first, however the throttle must not be at 0. If I raise the throttle up a little, then turn on the quad, it always arms. If the throttle is at 0, and then I plug in the quad, it usually arms but 1 in 3 times it doesn't.
Is this just an idiosyncrasy of the NAZA?
The only thing, is calibration of the ESC's. In the past, I always calibrated them with no voltage attached to them. In my current quad, this is difficult to do without desoldering things. Is this an issue?
Thanks

 

[Motopreserve]

As far as I have always understood it - for every RC situation (cars/truck, planes, quads etc) the radio always goes on first. It surprises me to hear that openpilot would suggest that the quad be turned on first.

If moving the throttle changes the arming success - that definitely sounds like it's a transmitter/stick cal issue.

When you say "no voltage" for calibrating the ESC, do you mean programming? They must have power for a proper calibration to the throttle channel.

The sequence would be: PROPS OFF!!!!

1. Plug ESC servo directly into throttle output channel of the receiver.
2. turn on transmitter, raise throttle to 100%.
3. Power the quad (and therefore the ESC)
4. Wait for beeps.
5. Lower the throttle to zero.
6. There should be more beeps.
7. Done!

 

[tomb18]

Hi,
Ok I think I was doing this wrong. I was plugging in each ESC one by one to the first channel on the NAZA controller, doing the 100% throttle, power on and then lowering the throttle. I was getting all the beeps though, but since this is not the throttle channel, then something is probably different. Are you saying I can plug the ESC directly into the receiver itself, bypassing the NAZA for the calibraation?
Thanks

 

[Motopreserve]

Yes, I'm actually saying you MUST do it this way if you want the esc/throttle cal to be correct

That's just for the esc/throttle cal. Before this - you should be making sure all sub-trims are centered and doing the Naza assistant stick cal. If you've done that already - just plug each servo in one at a time (you could make a 4-1 harness) to the Rx throttle out (probably channel 3 for Futaba?) and do the procedure I mentioned earlier. At least then you'd know for sure that's out of the way and correct - and we can diagnose from there.

Let us know how you do.

 

[tomb18]

OK, I redid the Esc calibration using the throttle channel. Now I notice that the motor response to the throttle seems much more linear and the lowest throttle setting is much better than before.
However, the, quad doesn't always arm.
I turn the transmitter on, then power up the quad. The LEDs initialize, they then flash green, then I get the amber light pulsing twice indicating it is receiving a signal from the transmitter and the sticks are not centered. If I then arm it, there is no motor activity.
If I unplug the quad and do it again, it seems the second time it works.
Note, I am not using the gps at the moment. Could this be a startup bug in the Naza?
Thanks

 

[Hexacrafter]

Have you confirmed that your throttle channel endpoints have not been moved?
Re-perform the Command stick calibration in the Naza assistant...
RC Tab.....Command stick calibration..... Click start and move the sticks around in a circle several times at MAX throw....
After completed, the green indicators for all channels should be centered under the center RED line.

 

[tomb18]

Yes, confirmed several times. Even when it fails to arm, I can connect up the computer and everything is exactly like it should be.
Anyhow, I decided to take it out in my backyard and try it out in ATTI mode.
Wow, really, really stable compared to openpilot. Works beautiful, just has a little wobble with stock gains. So that's my next step.
None the less this is perplexing.
Does it have something to do with my ESC's? They are RangeVideo 40A OPTO Simon K .
Thanks

 

[Motopreserve]

Do they beep when they don't arm?

 

[tomb18]

Yes they do!

 

[Motopreserve]

Sometimes some ESCs don't play with certain FCs. Particularly the ESCs labeled as "opto." I've never had it happen with a Naza, but that may be what's going on.

IIRC, it based on the fact that the FC is not delivering the level of signal to the esc to say "ok, ready to go."

Do you have another set that you can try?

 

[tomb18]

Well, this might be solved!
Yesterday during my limited flight testing I hit a branch of a tree. This caused 2 leads of the three lead wire going to one ESC to come off.
However, when I looked at the leads, the sockets themselves were actually ripped off, and instead of just seeing the remnants of a bad solder joint, there was actually one whole layer of the circuit board attached. So they broke off very cleanly, taking one layer of the circuit board with them.
So I had a spare, and I replaced it. Now, every time I arm the copter it works! Never before did that happen. SO perhaps there was something not just right with this one ESC, and NAZA therefore disabled all of them. That would seem to be the case. Everything now works as it should.
Thanks for all the help along the way.
73 Tom

 

[Motopreserve]

Glad you got it sorted.

It's worth checking all your esc solder points and connection. If it happened to one, it could....

Good luck and fly safe!