Problem troubleshooting with my ZYX (with video)

[Gregchico]

A few flights ago my heli took an abrupt turn while in the air and crashed hard. I was out of my flying comfort zone trying some new to me 3D moves and just figured it was me that caused the crash.

I rebuilt the heli, everything bench tested fine and took it up again. 2 minutes into the flight, I lost control again and crashed, but this time in basic flight so I knew was not operator error this time.

This time I gave it a lot more bench testing. Sometimes gyro will cut out, not reboot (I don’t see the flashing light sequence) , but just freeze. Just setting there moving the sticks, this can happen when both the motor is spinning or fully unplugged. There does not appear to be any binding.

I have tried grounding the tail shaft to the boom and the boom to the motor mount and tested it with my continuity meter. No changes in results were experienced, so I don’t think static is the issue.

All electronics are stock Blade 450 3D, EFlight (servos and ESC), but it does have the EFlight 440 motor over the 420 (but no changes were noted with the 420 back in it).

I have re-flashed the gyro firmware, adjusted the pitch and roll gains. It accepts programming and changes.

It does not "fail" every time. When it does, it does not "fail" at the same anything.

Most of the time the electronics (just the servos, not the ESC) stop responding or but this test showed a little more of a dramatic result. Before this videoed test, it passed all bench testing (motor unplugged).

Any advice or suggestions are welcome.

[Dr. M]

on first read I would've suspected static, but it sounds like you grounded your tail already.

Doublecheck the gyro compensates in the right direction on all axes. Then take off the main blades and disconnect the tail control rod from both ends. Spool up on the bench and check for vibes.

Also check to see if the gyro PCB moves inside the case: sometimes it's a little loose and can cause weird issues when it vibrates. If it is, open it up and add a few small pieces of double-sided foam tape to secore the pcb in the case.

[Gregchico]

Thanks for the suggestions.

I was hesitant to crack the case open but I agree there could be something loose. Would double sided tape or a shoe goo type glue be better to secure things in there?

[Dimitris K]

I had problems with random tail twitches and once with a locked aileron servo,
which disappeared when I lowered the Spectrum AR6200 Rx voltage to 5 volts
I put a capacitor in parallel with the ESC output voltage, restored the voltage to
6 volts and after 40 flights I have no issues at all. See more details in my post.

A friend has installed a ZYX at his Align 500 and he has not experienced any kind
of such problems, but he is using a Futaba Tx/Rx. Some people insist that Spektrum and JR
receivers are more sensitive to ESD than the Futaba ones. And the capacitor,
apart from acting as an energy storage smoothing the Rx voltage, it also acts as
a short circuit for any unwanted AC signals ( like from ESD ) appearing at the
Rx voltage input.

[Dr. M]

Originally Posted by Gregchico

Thanks for the suggestions.

I was hesitant to crack the case open but I agree there could be something loose. Would double sided tape or a shoe goo type glue be better to secure things in there?

I used the same double sided foam tape that secures the gyro to the gyro plate. 3-4 small pieces is all it takes to make sure the board isn't rattling around.

I also like (and use) the approach suggested by Dimitris K above. Grounded tail shaft, and a 1000μF electrolityc cap plugged into a spare port on the Rx. I too observed that Spektrum seems to suffer more from ESD and other electrical glitches than other radio systems, so I decided to give it all the help I can. That being said, I don't have a cap on the Protos (AR6210+sat DSMX) and observed no glitches after grounding the tail. So YMMV.

[Dimitris K]

I used the same double sided foam tape that secures the gyro to the gyro plate. 3-4 small pieces is all it takes to make sure the board isn't rattling around.

I would also recommend you to follow this advice by Dr. M.
Just 3-4 small pieces for the peace of mind ...

[Gregchico]

I opened her up. I did not see any obvious breaks, cracks or issues. I was actually surprised on how boring it was in there. I guess I was expecting "more guts" or something. Taking Dr M's advise I did place some foam tape (3m outdoor tape) on the board away from what looked like thermal transfer contact paste.
I will put everything back together tomorrow (family willing).

Thanks for the help.

Greg

[youturnjason]

I had a similar problem when first setting up my heli. Make sure theres no binding. Move the sticks to all 4 corners at both full positive and negative collective. If my servos started to bind it would cut out. I'm thinking the binding caused the servos to draw more current which was too much for the bec.

[Gregchico]

Just a update. It had nothing to do with the ZYX....

I bought a parts bird and just started playing with and replacing the different components, swapping things out and seeing how it goes. I would place the different components on my bench and just wiggle my control sticks for 15 minutes at a time to see what would happen.

As it turns out, the stock ESC was cutting out and my elevator servo also would cut out/slow down after a few minutes. I have no idea if one problem caused the other. Once I removed both those parts, I had no problems.

The ZYX is back in service on the spare with 15 flights since the rebuild with no issues.

Thanks for the help.

Greg

[Tom-jack]

Any help any one can offer with several problems.
Im in oregon and the only heli guy arround, the closest heli hobby store is 10 hours round trip. So i am on my own. Have been working on a trex 500 and installing the tarot zyx gyro and head. I (believe) my mechanical setup is correct. swatch plate level in all positions, servos working correct and so forth. Using the programing box to program. Used the programming box settings except where I needed to change the basic. Did not have much luck as most of the settings, such as "yaw p, yaw i yaw d" and so on I do not know what they stand for.So I have looked for a defination of each function within the programing box. No luck.
I did find a thred in setup with various settings listed by settings of each item in the program box. I used the two trex 500 in an average mix of the two. Better luck. Yea, although I still am in the dark on actual correct settings which brings me to the first question. I have tail wag at start up and heli shakes like a dog as it get light on the skids. Also computer skills are weak and I have been unable to post a question. PLEASE indicate how I can respond to any reply and if you have the time how I can post, the FAQ does not explain adequately. Thank you in advance. I know Im asking a lot.

[Mikej]

Tom-Jack,

It is not essential that you full understand each setting as the standard 5 give some good starting points - I use soft 3D (the middle one). If you have tail wag then simply reduce the tail gain set in your Tx.

Good luck,
Mike