450 AR7200BX Tail wagging

[jcfernan51]

I took the heli up today again and noticed that the tail wags when I command collective pitch or it is unstable when the wind picks up. I watched the set up video again, both basic and parameters and I am confused as to what to adjust.

1- How do I know when I am in Rate or Heading Hold (HH)? Okay this is my understanding, when in HH the tail try to hold its position. If the heli rotates left on its own (wind induced) the Gyro compensate in the opposite direction unless it is been commanded in that direction. I know if the LED is blue after initialization it is in HH which is how I should fly. Mine is always blue but is there a switch I am supposed to set to switch between the two modes or once the gyro is set up is always in HH? Is there ever a time when I want to use Rate mode?

2- Once the basic set up is completed the manual enters "Dials and Tail Gyro Gain" this is where i am kind of loss. It starts with the three dial settings, where #3 is the one I think I should play with to try to eliminate the wagging during pitch pump. But then goes into parameter setting D - Tail Heading Lock Gain which state
1- Start with Heading Lock gain set to low or very low tonight I adjusted mine to Low and maximize the tail gain in your transmitter. Where in the transmitter? is this the Gyro menu setting? If it is, what value should I set the 3 position switch to start?
2. Increase the Heading Lock gain in the AR7200BX until the desired result are achieved.

Then there is Parameter F. Tail—RevoMIX I watched the video and I understand what is does. While watching the video I changed it to Low but I am going back to factory before I fly tomorrow. I don't want to change to many parameter at one time and I am not convinced this has something to do with tail wagging or wind instability.

As you can see lots of questions. I will continue searching the forum for answer.

Thanks in advance,
Juan

 

[Tony]

Yes, you will use the gyro menu in your Tx. I would start with position 0 at 42, 1 at 45 and 2 at 47. This will allow you to just flip a switch to adjust tail gain to try and get it locked in. Give that a shot and let us know if it helps.

 

[jcfernan51]

update, I set up the Gyro as stated by Tony no more wagging, Thanks Tony. What I have now is hunting which searching the forum now I need to check the mechanical. Tried to post a video to show the hunting but within 1 minute the battery in the camera died. I will post a video.

Oh, one more thing when slowly spinning the heli, I guess it is called pirouette, the heli drift. I know there is a setting in the AR7200BX for this. My question is how do I know which servo to tweak since this menu will affect other settings and I do not want to make it unstable. I do not have full control of this thing yet.

 

[Tony]

Lets get the tail under control before we dive off into advanced settings to stop the piro drift.

In your gain menu, raise your gain until you get a fast wag. Once that happens, lower it by 5% and you should be locked in. Let me know if this helps.

 

[jcfernan51]

Update, I checked the tail hardware and it was sticking at on of the extremes. Upon inspection I found one screw in the blade holder that if it is barely tie it will cause this so I put more lock tied and left it kind off lose. I was hoping this was the issue, but no.
I set up the heli with the following Gyro numbers #1 - 45.5 , 2 - 56 3- 64.5. At 45.5 still the same, it hunts. At 56 started wagging so I never tried 64.5%. see video. I then created profile with 1 - 45, 2 - 47, 3 - 50, no change still hunting. Charging batteries now, I will try again with values between 50 and 56. I am assuming I do not have to power cycle the gyro for the new numbers to take effect.

[video]https://youtu.be/Z2Fg-28MjAc[/video]

 

[Tony]

That tail is rock solid IMO. If the tail is kicking out in hard pitch pumps, there is a precomp menu that will adjust this setting. When I think tail hunting, I think a slow tail wag.

 

[jcfernan51]

So this is normal then, that tell how much I know. Which menu are you referring?

- - - Updated - - -

Going through the manual I started reading Parameter D, after reading the "Important" paragraph I think I need to adjust the Rate mode because when I set the gain to a negative number (rate mode) I remember the tail drift in the same direction as the tail is kicking when pitch pump. I will adjust the link to stop the drift and re set menu point E. Also, I do have Parameter B set to transmitter so I can play with D/R and Expo. First I will adjust the link and rotor travel limits.

 

[Tony]

Let me know how it goes.

 

[jcfernan51]

Finally got a chance to hover again. I adjusted the tail pitch until the heli started a slow clockwise piro in rate mode then I switch the Gyro to lock the tail. But when I gave collective pitch the tail still kicked out. I played with parameter F in low and Hi, no help. I think I am going to try to change the pitch in the blades from 12 deg. to something in between 10 and 11 and see if it decreases the amount of torque. I have not played with parameter D because I am confused of the approach.

1. Start with Heading Lock gain set to low or very low and maximize the tail gain
in your transmitter.
2. Increase the Heading Lock gain in the AR7200BX until the desired result are
achieved.

This is confusing to me, this is my interpretation, After I set the parameter to low or very low I maximize the gain in the Tx till just before tail start wagging and then increase the Heading Lock gain in the AR7200BX. I would think this will cause the tail to start wagging. Then, I guess I have to decrease the Tx gain until it lock. Am I correct? is this what I am supposed to do?

 

[Tony]

Are you flying in normal mode or idle up?

 

[jcfernan51]

I am flying in idle up. I just made a video of something I noticed when I was rechecking my setup. Here it is.

I started with the blades in center position. As you can see when I rotate the heli CCW the pitch changes like it should, back to center and the pitch is back on center. But when I rotate CC it will not pass center.Then if I rotate CCW again it add more pitch. When rotate back to center it is no longer center. It looks like it zero itself out when I stopped the CC rotation and started the CCW rotation to go back to starting point, it added more pitch. Any ideas?

[video]https://youtu.be/ycctSfZTuzw[/video]

 

[Tony]

In that video, the blade on the bottom is backwards. This will have a horrible effect on the tail of the helicopter. Swap that blade around and see if that fixes the issue. The tail should be turning CCW as you are looking at it in the video.

 

[jcfernan51]

Wow, you know how many times I looked at this. This is why a pic is worth a 1000 words and definitely a second set of eyes. I changed the blade but I am charging the battery. Is the tail behavior normal?

- - - Updated - - -

One thing I noticed, you have replied twice and I have not received an email notification.

 

[Tony]

I don't think it's normal. In rate mode, the tail should push the trailing edge towards the direction of movement, then snap back to center when you stop. In HH mode, it should do just as it did and push the blades out and hold them until the helicopter comes around to the heading that was set in the gyro. IMO, if this were mine, I would be redoing the tail setup in the gyro. Make sure you pay extra attention when you are doing your end point adjustments and make sure you have your slider right in the center of the shaft before you do the endpoints.

 

[Tony]

I'm not sure why you are not getting the emails. I checked your account and you should be getting them. I will have to do some more testing to find out why they are not being sent out.

 

[jcfernan51]

Thanks, I did not think it was. I was thinking the same thing and redo the Gyro set up. is there a way to reset the Gyro and start over again? or just over write the current settings.

 

[Tony]

Made a quick change to the email settings. We will see if it works.

 

[Tony]

Thanks, I did not think it was. I was thinking the same thing and redo the Gyro set up. is there a way to reset the Gyro and start over again? or just over write the current settings.

Yup, you can do a factory reset on the gyro. Here is what it states in the manual. Just remember, you will have to do a complete setup after you do this, not just the rudder.

Factory Reset
To erase all AR7200BX settings:
In any setup menu (A through N), press and hold the setup button for at least 10
seconds until LEDs (A) – (N) and (J) quickly flash to confirm the reset.
Any previous programming is deleted during a reset.
CAUTION: Do not attempt to fly the helicopter without doing a complete
setup procedure after a reset. If you do not complete the setup, the helicopter
will crash, causing property damage and injury.
Unplug all servos and remove the servo horns before resetting the AR7200BX.

 

[jcfernan51]

No emails, oh well I just have to check in often.

Anyways, I just had a mishap while checking the settings. I made the mistake of placing the heli between me and the radio with throttle at mid stick (checking pitch) and Hold switch disabled (don't know why I always keep it on). Guess what happened after I cycle through all the settings... yep... the heli started to spool up and I could not reach the radio . I got down low reached and grabbed the landing gear to prevent it from lifting and tilt it away from me. Mean while a power cord from the radio charger got tangled on the tail rotor preventing me from lifting the heli so I can reach the radio. The main blade stroke the table and a lamp a few times and the motor shot off. I guess it has a shot off safety or the good Lord prevented a worst scenario. Tte main shaft is a little bend but I also hear a grinding noise so I need to take it apart to inspect the bearings.

Leave and learn, what did I learn "always keep the radio with you"

 

[Tony]

I will bet you have stripped tail gears in it now. Sucks that it happened. Sometimes though, it takes something like this to make you realize just how dangerous these things are. Glad you escaped without injury! That is what matters most. And yup, next time, make sure to have TH on or better yet, unplug two of the motor wires. Hope you get it repaired quickly.