One last request for help.....I promise....The dreaded tailwag

Brian fred carr

Site Moderator
Mentor
OK..so I have the copter flying with the gyro working, but it is wagging its tail back and forward like an excited puppy,
so to cure this do I do it through the radio or do I have to alter the switches on the gyro, also if I have to do it with the radio can i do it on the fly............I have to set this bird up, my family are starting to hide behind furniture every time I get her out the box and both cats now despise me....but I am sure that once this tailwag issue is resolved I will be posting videos of my maiden crash......... er I mean flight......... once again thanks
 

dezertdog

Senior Member
Tail gyro is too high. If it's got a pot, turn it down a little bit at a time till the wag stops. If the gryo is controlled via a knob on the Tx do the same there.
 

glydr

How many letters do we ge
It sounds like gain is too high. With the HK401B gain is adjusted in the transmitter (you may have that set up on travel adjust on the gear or aux channel).

Get out to the field and bring up your rate adjust menu. Pop it up in a hover, see if it wags, if so put it back down and adjust gain closer to zero a few percent. Keep going until the wag stops.

The sweet spot on gain is when you hit collective hard from a hover, the tail kicks out ever so slightly and recovers (in heading hold of course).

Another source of the problem could be that tail servo. I have seen a similar servo hold a tail in a hover on a TREX 450, but then again that bloke crashed that day while hovering and he didn't know why. Tail servos really do need to be strong and fast because they are doing a high load job and need to do it quickly.

For good value I'm currently rating the Ino Lab: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=10522

I also currently run a Turnigy DS480 (it is actually on the heli in the photo in my avatar!) which was good value but doesn't seem to be listed anymore.

G
 

Richie

Junior Member
what heli you running and what gyro ? I would agree with the lads about gains, but if by chance it is not the gains check the servo tape, if its the thick stuff and you can wobble the gyro then it may need changing out. i fly a Raptor 50 and the virbations are a tad worse than that of an EP heli... i changed out the servo tape for velco and have never looked back..... on the theme of the tail servo's its also worth noting if your pushrod is a stock wire jobby or a carbon pushrod....if its the wire one personally speaking i would rip it out and go with a harder carbon push rod.
 
Last edited:

Ak Flyer

Fly the wings off
Mentor
I also need to know what your setup is. I had lots of trouble until I learned that I needed to set up my gyro in Rate mode before tuning it in heading hold. I am running a really nice Futaba GY520 on my Blade 400 and this extra step made all the difference.

It would also help to know your radio. As Glydr said you need to check it and then set it down before making adjustments. NEVER adjust the rudder trim on your transmitter. Your trim and subtrim must stay at zero for it to work.

If you have a flight mode switch or gyro switch or one you can assign, I HIGHLY recommend using it. You will find that you need to have a position for rate mode and one for heading hold. Leave it in rate mode and make your short flights with adjustments in between on the ground. After you get it set, you can switch to heading hold mode and see what it does. If it wags out of control you can switch back to rate mode to get it down and make your adjustments.

+1 on the carbon pushrod.

Oh, and the rate mode adjustment is a mechanical adjustment. That helps the tail know center, then it's got something to work with when you go to heading hold.