Unique gyro problem - please help!
 

Hi All,

I pretty much learned how to fly thanks to the people on this forum a couple years ago with a 22E and a Belt CP, but now I'm back on here with a very unique problem with my electric Trex 600. I've been flying this one for about a year and couple months ago I upgraded the 6ch RX to a 7ch AR7000 unit. Ever since then I've been having issues with my GY401 gyro where it would not stay in HH mode and make the tail slider wonder over to one side where it would then stay. Specifics as follows:

Turn on heli in normal flight mode with gyro set to rate, all is good. Heli flies with gyro in rate.

Turn on heli in normal flight mode with gyro set to rate, then change to Mode 1 / Idle up. Heli will fly fine with gyro set to rate, but when you set it to HH the tail will slowly slide over to one side and stay there with gyro light flashing.

Turn on heli in Mode 1/Idle up and turn on HH....it will work fine with a solid red light on the gyro and tail holding rock solid. The same goes for if you turn on heli with HH already turned on etc.

So, right now it would appear that I can only get my heli into HH mode if I fire it up in Idle up, which can be dangerous if you miss something.


Please note that I've waded through many a forum and have tried different combos. I've been using the Gyro setup pages on my DX7 but have also tried running the gyro gain of the Gear and AUX 2 channels with similar results. If anyone could share how they overcame this or what they think might be wrong that would be greatly appreciated as I'm quite stumped and a little frustrated.

Also, note that the heli flies very well when it has been started in Idle up...I was just hoping not to have to plug the battery in when it's in this mode...I'd rather start in Normal flight mode with throttle on zero ;-)


Thanks for your time,

Tom

RE: Unique gyro problem - please help!
 

You have to start the 401 in heading hold mode.

If you want to fly in rate mode for some reason, just put the gyro on a separate switch but the 401 must be initialized in HH mode for it to work correctly.

RE: Unique gyro problem - please help!
 

Thanks for your reply, however when I start the heli in HH mode it will only stay in HH mode in Normal flight mode....when I flick the flightmode switch to put it into Idle 1 or Idle 2 the HH drops out and Gyro light starts to flash twice every second. Also, at this point the tail slider moves over to one side where it then stays...

What do you reckon this could be??

RE: Unique gyro problem - please help!
 

Are you testing this when it on the bench or in the air?

It sounds like the gryo is not activated in the other 2 flight modes. What kind of radio do you have? What is your gain set to?

RE: Unique gyro problem - please help!
 

Googles,

I've been testing this when I'm trying to fly out on the field. I don't fly it when it's not activating properly ;)

The two values are at 30 for rate and about 70 for HH. With these it flies quite well when I can get it to stay in HH.

The radio is a Spektrum DX7 (heli model)

RE: Unique gyro problem - please help!
 

See if this helps any...

[link=http://video.helifreak.com/?subpath=finless/gaui/hurricane550&filename=tailsetup.wmv]401 setup with DX7[/link]

[link=http://video.helifreak.com/tmp/025fb8c1a5d60ee5f212a195cdb056c3/gyro_setup.wmv]401 setup[/link]

or here:

[link=http://video.helifreak.com/?subpath=finless/generic&filename=dx7v3.wmv]DX7 setup[/link]

RE: Unique gyro problem - please help!
 

Your rudder trim is stored per flight mode. You have different rudder trim in normal than Idle up.

The double flash means that your gyro is recieving a rudder input.

Center your transmitter rudder trim in all flight modes and make sure the light says solid no matter what FM you're in.

RE: Unique gyro problem - please help!
 

Barracuda - ah I see, I bet that's what's happening! I shall go and check that as soon as I get home tonight. It was a long time ago since I did the RX swap and I vaguely remember messing around with the rudder. I will set all trims to zero and see how that goes and possibly "redo" the gyro setup.

Goggles - thanks for the links, I'll go thru these tonight and see how they compare to my current setup on the DX7 and also mechanically on the heli.


Thanks for your helpv guys! Very muchly appreciated!

RE: Unique gyro problem - please help!
 

Well guys I went and did those things last night and voila! - solid red light and a solid HH tail rotor in all 3 flight modes. Yep, in flight mode 1 the rudder was over a fair bit and a smidge in the other modes.

I was wondering why I did it like this and it occured to be that I had to do this to the basic gyros on my E-sky Belt CP heli's and unknowlinly did the same for the poor GY401! I didn't know the extents of what this gyro is capable of and definitley didn't know that it would find and store it's own rudder settings!

Thanks again for the help!

RE: Unique gyro problem - please help!
 

Its not the gyro storing the settings its the radio.

The gyro initializes and memorizes the center pulse of the rudder channel and assumes this as nuetral. This is the 3 second fast flash and why you can't touch the rudder or move the gyro while its booting.

Once its stabilized in heading hold mode, any deviation from that pulse (usually around 1520us) it considers as a command to turn (double flash). All that happened is when it memorized the center in whatever mode you initiailzed, when you changed flight modes it took it as a rudder command started double flashing.

RE: Unique gyro problem - please help!
 

Ah man, I was way off...and that all makes perfect sense now!
Well I took the bird out for a flight last night and she was nice and solid. I also never knew that you had to start the GY401 in HH mode. Ahwell, she's working a treat now.

RE: Unique gyro problem - please help!
 

Thanks for sharing ,guy

RE: Unique gyro problem - please help!
 

Thanks for sharing

RE: Unique gyro problem - please help!
 

No worries man