Yub, yub, cmdr!

Those darn Aileron Servos are really pissing me off.

They keep on buzzing, even at neutral sometimes. They buzz intermittently, even when there is no change on stick input.

There is no part that is hitting any part of the wing.

Servos work fine without moving the ailerons (ie I take the snap thingy off the control horn then I move the sticks).

They are really pissing me off. I just can't fix them.

PS How do you guys cut your pushrod wires? I just don't have cutters powerful enough.

Tired Old Man

My Feedback: (1)

Take the wheels off of the servos and tuirn on the radio. are the servos buzzing? Move the appropriate stick from stop to stop and return to neutral. Are the servos buzzing?

If they are not in both tests, the problem is in the linkage set up and not the servos. Look for binding or vertical alignment problems. I have had servos with perfectly aligned linkage buzz when a vertical load was being placed on them by the linkage. You could measure and eyeball the linkage all day and see that it wa inline with the servo arm, but fail to note that there was an angular difference vertically in the linkage.

Also look for a clevis pin going through the servo arm that is too tight.

I use a large pair of end cutters or a Dremel cut off wheel to cut my 4/40 wire with. Then I file the end square if I used the cutters. If your really desperate, I suppose you could use a hacksaw if the wire was properly clamped in a vise, but I wouldn't want to.

Yub, yub, cmdr!

Ehh. I'm still kinda new.

They work fine w/o the wheels.

No buzzing in both tests.

I just don't get what you mean by 'vertical alignment problems'.

My servo arms/wheels are in line with the control horn ie I use a ruler and put one end on one side of the control horn and put the other end on one side of the servo wheel. The ruler is perpendicular to the trailing edge.

But I don't know what vertical alignment problems are.

DBCherry

My Feedback: (4)

David,
When you remove the control rods from the servo 'wheel', do the ailerons flop up and down when you move the wing around, or both droop down on their own? Or do you have to use you fingers to move them up and down?

If they are stiff they are pobably putting enough strain on the servo to keep it from "centering". ie. When you release the stick, the servo will move clockwise (or counterclockwise) to try and center itself. If one or both ailerons are a bit hard to move, then the servo will turn a bit too far before it stops. It will then have to try to move back a little to "center" itself. But again it will overshoot center, and have to try again.

The result of the servo hunting for center is 'buzzing'. It would be my guess because you were having a problem earlier with the aileron hinges. In addition to the hinges, there's another spot that you may have overlooked. Be sure that the ends of the ailerons aren't catching on the edges of the wing. You need a little gap there too.
Dennis-

pimpsurfer

I had that problem with my aerobird. It worked fine the night before, I went to go fly the next day and no left servo movement, nothing was hung up, so I went home and pushed with a pair of tweezers and then it started working again. It seemed like it was stuck or somthing.

MinnFlyer

My Feedback: (4)

David, don't worry too much about the servos buzzing. Try this... get one of them to buzz, while it's buzzing, gently tap the aileron one way or the other. If the buzzing stops, you really have nothing to worry about because once the engine is running, the vibrations will let the servo center itself.

DBCherry

My Feedback: (4)

Good point Mike.

David,
As long as the servo can move the control surface without too much trouble, it shouldn't be an issue. The airflow over the surface while flying will put more pressure on it.
Dennis-

Yub, yub, cmdr!

Thanx everybody...

Now I can say bye bye to my fears!!!

If I tap it, it stops buzzing.

I made sure there were gaps everywhere. Yeah, the ailerons are kinda stiff. They droop very minutely, like maybe 1/16 of an inch. The just hinged (with good hinges and plenty of gap) rudder droops like 1/8 of an inch. The just hinged elevator droops like 1/8 of an inch too.

PS How do you guys cut pushrods? We don't have powerful enough wire cutters and no dremel, but we do have a Jigsaw!!!

CafeenMan

You'll need to buy some kind of tool to cut the wire. For Music Wire, don't even try side-cutters or anything like that. I have a ton of tools, but the only tool I have that can cut music wire is a cut-off wheel in a Dremel.

For threaded rod you'll need what the man said - side-cutters or a Dremel. If you're strapped for cash, then the side-cutters are a lot less expensive.

CafeenMan

PS. You could get a metal file and try to saw through it using a corner of the file. Or you could spend the next 10 months filing it down from the end.

ballgunner

My Feedback: (1)

In the days before Dremel cut-off wheels became common we used to use a triangular file. File through from both sides with one edge of the file. If you have a bench grinder you can square off the ends that way or do it while the wire is still clamped in a vise. Don't even bother with a hacksaw or you will spend more on blades than the cost of a new Dremel.

MinnFlyer

My Feedback: (4)

Yub... You mean you forgot to ask for a Dremel for Christmas!!?? Tisk, tisk. Do like Ballgunner said. The edge of a file works great.

Yub, yub, cmdr!

Hehe...

Hmm I saw a dremel-clone at Christmas Tree Shops for fifteen bucks.

I'll buy that! (er, rather, I'll persuade my parents into buying that!)

MinnFlyer

My Feedback: (4)

Yea, when I say "Dremel" I mean it in its generic term. I forget what brand mine is, but it's not Dremel.

DBCherry

My Feedback: (4)

Just be sure it has "cut-off wheels", or buy them separately. They're real handy.

A good pair of heavy pliers with side cutters will cut push rods/music wire, but it's real hard. Takes a lot of hand strength for some of it. A "Dremel" just takes a bit of patience.

One note; be VERY careful with the cut off wheels. The standard ones can shatter easily and send sharp bits flying everywhere. You really don't want those in your eyes, so get a pair of inexpensive saftey glasses.
Dennis-

Yub, yub, cmdr!

okay!

just noticed aileron pushrods are NOT perpendicular to the Trailing Edge. Instead the servo wheel and the control horn are in the same straight line, of which the line is perpendicular to the Trailing Edge. EEkkk.. The Tiger II manual did not mention this... But at least I gained some epserience!

phread59

To cut off a metal push rod and not having a saw try this. Take a flat file and use the edges and just score the rod on opposite sides of the rod. Use 2 pairs of pliers and grip the rod on either sides of the score marks as close to the marks as you can. Just twist the rod slightly back and forth and the rod will snap. Use the file and dress up the end. Just remember to score the rod right across from each other. I have built many a plane without a Dremel tool. I don't even have one. I use my muffler cutter from work and hand tools. I guess I am just an old fashioned old fart.

Mark Shuman

Yub, yub, cmdr!

My dad's an old fart too.