500 tail servo acting up

[DOG]

Hey everyone. I decided to take my 500 out to play today. It was almost a disaster It was a little windy but nothing to bad. As I was flying I've notice that sometimes when I yaw left and try to yaw back right... it wouldn't yaw and visa versa I brought the heli down after getting control once again and checked everything out. It seem fine to me anyway. Just to be safe I increase the tail gyro a little bit because it was a bit sluggish. I know I shouldn't take her back up but I did The same thing happen and i finally came to my senses and brought her in before she crash. My tail servo is fairly old compare to my cyclic servos and was thinking if the tail servo was showing signs that it's going bad. I'm in the process of breaking her downing at the moment and going through everything while she's apart. My question is, i never had this problem before with the 500 and this is a new bad behavior she just develop. Does anyone might have an idea what could be the problem? I know there's a few things that could go wrong but maybe you can narrow it down a bit for me to check it out. I'm going to install a brand new KST 515MG servo that I had sitting around for awhile now. I'm all ears for any one suggestions. I would appreciated very much

[pvolcko]

I'd check for binding in the linkage, slider, etc. I'd also power up the electronics (no main motor) and then pinch the control rod to the tail and move the yaw left and right to see if it's sluggish, having trouble working against the pinch force, etc.

If that checks out, make sure you transmitter was set to run the tail in position mode instead of rate mode, and that the gain was high enough. What FBL do you have on this?

[DOG]

Hey Paul. Thanks for responding Well I checked the binding on the linkage,the slider and checked the bearings to see there wasn't any obstruction like dirt or any nicks. Everything seem smooth and lubed. I did move the yaw left and right a few times to see if any sluggish behavior but nothing. It seem like when it was flying that servo had a brain fart and forgot to move I haven't touch anything in the transmitter since I don't use rate mode but I did check that too. I thought the gain wasn't high enough because I rarely fly when it's to windy out and did increase it some. The FBL unit I have on it is The AR7300BX and I went through the whole setup just in case I might of did something wrong but all went well. When I first got the 500 from a friend 5 yrs ago, he had turnigy cyclic servos and the Align DS525M tail servo on it. I heard back then that the Align was a wonderful tail servo to have. The cyclic servos were Turnigy servos and I didn't care for them. So I bought 4 new KST DS515MG servos to replaced them all. I never change the tail servo I don't know why but I didn't. I'm thinking that the Align servo was ready to retire and it was going bad and that's why it was hesitating to my command. After further inspection and couldn't find anything wrong with the tail unit or linkage I just decided to replacing the Align with the KST that's been sitting around for 5 yrs but brand new still in the box. Everything seems fine so far but I haven't had a chance to get her airborne yet to see what happens. I'm waiting til the winds die down. Tomorrow morning is going to be my test flight. Hopefully all goes well or I'll be ordering parts for her. Thanks again Paul and I'll let you know how she does

[pvolcko]

Could have been a frayed or loose wire too. Kind of thing that can develop over time and many flights. Hope the new servo works out.