Flap motor chatter?

[Garage Guy]

I've started noticing some chatter in the flap motor in our RV-6.

Symptom is an approx 4 Hz small amplitude jerky oscillation superimposed on the flap motion when lowering flaps, accompanied by a little noise. Doesn't appear when raising flaps, and a little opposing force will damp it right out (so you only notice this when lowering flaps on the ground).

Anybody seen this before? Anything to be done about it?

Thanks for any help...

--Paul

[scard]

I am beginning to observe the same thing. No ideas just yet.

[Sam Buchanan]

Originally Posted by Garage Guy

I've started noticing some chatter in the flap motor in our RV-6.

Symptom is an approx 4 Hz small amplitude jerky oscillation superimposed on the flap motion when lowering flaps, accompanied by a little noise. Doesn't appear when raising flaps, and a little opposing force will damp it right out (so you only notice this when lowering flaps on the ground).

Anybody seen this before? Anything to be done about it?

Thanks for any help...

--Paul

Flaps on my RV-6 have exhibited this oscillation for several winters, say below ~40F. Never has caused a service problem.

[Sam Buchanan]

Originally Posted by Garage Guy

I've started noticing some chatter in the flap motor in our RV-6.

Symptom is an approx 4 Hz small amplitude jerky oscillation superimposed on the flap motion when lowering flaps, accompanied by a little noise. Doesn't appear when raising flaps, and a little opposing force will damp it right out (so you only notice this when lowering flaps on the ground).

Anybody seen this before? Anything to be done about it?

Thanks for any help...

--Paul

Flaps on my RV-6 have exhibited the slight chatter for several winters, say below ~40F. Never has caused a service problem.

[Andy Hill]

The "chatter" might be related to friction building up between the flap and wing skin - where there is either an AL or Plastic low friction strip...

You could consider lubricating it to an extent... and see if it alters?

Andy
RV-8 G-HILZ

[Garage Guy]

The "chatter" might be related to friction building up between the flap and wing skin - where there is either an AL or Plastic low friction strip... You could consider lubricating it to an extent... and see if it alters?

That would be an easy thing to check, all right. The UHMW tape on our flaps is in pretty good condition, so I didn't even think of it. Flap hinges were on my list of suspects, though.

But what I ended up doing was going after the flap motor (ours is a Pittman labeled one) and separated it from the gearbox. You could see a little wear on the gears, but it didn't look too bad. Not much grease in there, but Van's says you don't want to have a lot. Anyway, I cleaned the motor shaft worm gear and regreased it and put everything back together and... problem gone. Smooth as silk now. So I guess that maybe the grease had over the years just worked its way off the gear faces.

Flaps on my RV-6 have exhibited the slight chatter for several winters, say below ~40F. Never has caused a service problem.

I read that ~40F as -40F and thought wow... it would be more than my flaps chattering at 40 below .

--Paul