Tail wag CGY 750

[birddawgg]

Okay, I now have 6 tanks through the YS60 and the tail just wags and wags. I was thinking it may correct it's self as I start to lean the motor a bit. I remounted the gyro sensor with foam tape, metal plate, and then black 3M and the first flight of the day it really calmed the tail down but by the second tank it was wagging pretty good. Could this be an engine break in issue or is there some work that needs to be done in the menu's? Also I backed off the tail gain and it just got bigger and sloppy, increased the gain and the wag was smaller and angry.

So ready to get the bird dialed in

[flyalan]

The first place I would start is the actual tail linkage.  It needs to be silky smooth and effortless.  Size all of the links including the tail pitch links. 
Are you using the Gov?  If so try turning it off and use a v-curve.  If the problems settles down its a Gov issue and you may need to play with the Gov Gain settings.


Cheers
Alan

[Kevin Dalrymple]

Check the linkage like Alan said. Also what tail servo are you running? Is it a 760 frame rate servo? There should be no wag with the 750.

[birddawgg]

I am running v curves for now. No gov yet and I am running a BLS 251.

[birddawgg]

As I think about it I didn't know if I was suppose to size the pitch links for the tail. I hope that is the issue.

[flyalan]

As I think about it I didn't know if I was suppose to size the pitch links for the tail. I hope that is the issue.

Yes those do tend to get overlooked but it can make all the difference. The tail control needs to as frictionless as possible.
Let us know if that solves it.

Cheers
Alan

[birddawgg]

So, I started to go through the tail to make sure everything is good. I know I needed to size the links. I pull the first one and get it sized. Pulled the second one and noticed that there was nearly a 1/4 inch of vertical play between the blade grip and the hub. The short story is the radial bearing didn't seat all the way when I reassembled the blade grip. So I did a little aim-n-flame and the radial fell the rest of the way into the blade grip.  So I am very excited and can't hardly wait until I can test fly it. Thanks for all the input guys, wouldn't know what to do with out you.

Scott

[flyalan]

Scott,
Glad to hear it sounds like that is sorted out.  Keep us posted!


Cheers
Alan

[birddawgg]

Well well well. I got a quick drive way hop in. The tail is calm, I actually had to increase the tail gain to 74% to get it to stop solid. Now to work on the gov and get the motor close to a final tune.

Thanks for the help so far ya'll!


Scott

[Greg Jackson]

Glad the wag is gone now.

[birddawgg]

Me too, actually the tail rotor hub isn't tapped deep enough on the side in question. I can't seem to find a shorter screw to make up the difference so I had to add washers to make up the gap, which means I had to add an equal number of washers to the other side as well for balance.

[Greg Jackson]

Are you using try-flo on the tail shaft?

[Rodney Kirstine]

I've got a pretty bad wag with mine, too.  It oscillates after I do a quick piro and stop and it also oscillates during fast turns in FFF.  I've checked it, mechanically, and it's smooth as buttah.  I've been dialing down the gain and I'm into the mid-40s now, which seem really low.  What kind of gain are you guys setting yours at?  Also, what kind of gain values are you guys using on the governor?  Just kind of want to know if there seems to be a fairly close grouping between some of you that are also running the CGY-750.

[Chris Sexton]

Does the cgy 750 have cyclic pre comp on the gov? I would be checking the gov gains if its oscillating under load.

sent from my Verizon Samsung Galaxy Note 2

[Kevin Dalrymple]

Yes Chis the 750 has precomp for the throttle and they need to be set up.

As far as adding washers to the tail hub to me that dose not sound right. Play between the grip and the hub is normal and designed that way. Are you sure the hub was not taped enough? 

What tail blades are you running on your Heli? And what size mains and tails are to running?