Servo Chatter?
 

Now I'm working on my Hangar 9 150 Mustang. It has a Evolution 40 engine with the Keleo exhaust.

I'm using a Hitec Aurora 9 transmitter and a 9 channel receiver.

Servo chatter happens with the gear down only. It happens when the flaps are up or in the mid position, not when fully extended. No chatter with the gear up in any configuration. I believe it is the gear servos mostly the left.

Thanks Red

Binding linkage (like a way too tight ball joint for instance) or incorrect end point adjustments can do that. Before replacing the servo, I'd try with the linkage disconnected to see what happens.

Thanks for the reply Mr Hicks. When I use the JR matchmaker no chatter at all. A comment at the field today was to try a different port on the receiver (I can do that). Another comment made was to get some cycles on the servo to see if things free up. That's easy and doesn't risk the plane. Also adjusting the EPA is easy as well.

Let me add some more info. My airplanes have set dormant for several years. The last two in a humid environment.

Today's flying. Had a good time, took the Hanger 9 P-47 with a Evolution 35 to the field today. Got a lot of help tuning and tightening screws. The last time it flew the engine quit 50 feet off the ground...let's just say it got a new fuse. Needs a little nose weight now to smooth it out, glad to see it flying again.

Welcome back Red!

Red, if your planes have been sitting around for a while like you describe, the connectors may have become corroded. Make and break them a few times and see if that helps. The same may have happened to the switch. Are you sure that the battery is OK? Dan.

Good idea's Dan, thanks. Yes batteries are OK. I guess I should remove the gear from the wing and make and break the the extensions.

Thanks Red.

It seem's if I work the servo (raise and lower the gear) 7 to 10 times it goes away. Then the next morning it's back but only takes 5 cycles to clear it up. Would you fly the plane if it was yours?

Red

Will they chatter if the linkage is disconnected?

Another thing to consider, when you cycle the servos several times, the servo load slightly lowers the battery voltage that may reduce the chattering. What brand and model servo are you referring to? Perhaps it is voltage sensitive. In some cases, some chatter is normal if the servo is held under a load. W/O seeing and hearing your particular situation, it is hard to diagnose in a forum.

They don't chatter when the wing is off and I operate the servo with a JR matchmaker. Matter of fact the left gear wouldn't work at all until I ran it that way. I got an idea when typing...I wonder if the servo ext connection might be corroded? I report back on that.

Update.

The servo is a JR sport retract servo.
Connecting and re-connecting the servo leads seem to make it worse. (sorry Dan, I see this was your idea, I slept between posts.)
I moved the end point adjustment and sub trim to max values (both directions) with the gear down and chattering... nothing changed, no different sound. So I don't feel like it was a linkage issue.

Even with the chatter the gear is down and locked. What about interference?

Red

Changed the RX from a Hi-tech 9 channel to a spektrum 9 channel...CHATTER IS GONE!!!!!!!!!