Hi, Im setting up a mariner 40 that I got a great deal on from a friend. Im having some trouble though with the aileron servos, they buzz, but only when they are at full extension in one direction or the other. I have the holes on the servo and control arm set to the weakest torque possible, and the servo's are FUT S3003's. I know that this is not healthy for the battery, and its stressing me out how to eliminate it. The arm isnt binding on anything, and it set us as simple as possible. Is it OK for it to run like this? Its only on full deflection in either direction.

You're right, the buzzing means the servos are stalled at full travel and will use up battery power at a prodigious rate.

I don't know what "weakest torque possible" means, but it doesn't sound good. Please describe your setup. How many holes out from the center of the servo arm do you have the pushrod? How many holes out on the control horn? What is your aileron EPA set at? High rates/low rates? Differential? How much travel do the instructions call for and how much are you getting before it binds?

Jim

If your radio has endpoint adjustment, just dial down the throw. Set the throw to the recommended amount in the manual. Sounds like you have too much throw in the ailerons.

I dont have EPA, and by the weakest torque possible, I mean that the rod is in the fartheset up hole in the control horn, and the farthest up hole in the servo arm (I know that the farthest up hole in the arm isnt good, but since the servo is set inside the wing for water protection, theres no way around that one). Also, after testing the stabilizer's I also get buzz in both of those, the vertical only when the servo moves off center, and the horizontal nearly all the time. I read elsewhere that buzz in big planes is normal, and this plane is a 7-8 pounder. The aileron has about 3/4 travel, what the manual calls for. Keep in mind that it only buzz's when its at full deflection in either direction.

You don't have EPA? Really? Well then, all you can do is get longer control horns. 3/4" sounds like an awful lot of travel for the ailerons. Is that each-way or total travel? You should put the elevator pushrod in the hole closest to the center of the arm. The Mariner is quite pitch sensitive.

Buzzing is normal in digital servos, usually used in giant scale airplanes. You don't have digital servos and the Mariner is certainly not a giant scale airplane.

I suggest that you find an experienced flyer to help you set that Mariner up. It sounds like you are on your way to a very exciting first flight.

You might want to check out the Seaplane forum here on RCU. The Mariner has some unusual flight quirks.

Jim

If it only happens at full deflection I wouldn't worry about it. After all, how much is of you flight is spent at full deflection?

Something you can do is to enlarge the holes in the Servo Cover Plates so that you can come in a notch on the servo arm

Hey Jim (this is sturdy flyer, thats my brother's account), I appreciate your concern

I dont have EPA because Im still using an analogue 4 channel old Futaba Conquest back when they had the metal face-plates and didnt look like crap. I want to get a 7CAP but the budget doesn't cut it right now (worst place to cut corners I know).

The 3/4 inch is a small 3/4 and is the total travel both ways, combined. The manual says 3/8 up and 3/8 down which is 3/4 both ways.

I did not notice which hole the elevator was in as it came with the stabilizer servo's in, I've fixed that for the most part, although they still buzz at near full deflection. I read exactly what you said about the large scale digitals, and someone also said its OK as long as the buzzing stops when its centered, and only starts at full deflection. Is it a good chance to bet that all my airplanes buzz when underway with air resistance acting on them?

By all means I am not new to this hobby, and this is my seventh plane among others, and I've know what you were thinking. I am not going to put this plane in until I'm comfortable with all the servo's and layouts, and I've been reading the reviews of the plane and all its potential problems (IE horizontal stabilizer connecter). I dont think she'll be too much to handle, minus needing to land absolutely dead on, because the reason it was so cheap was the previous owner let the left pontoon touch down first, and it spun out and doused his electronics. He was understandably fed up.

I should of posted in greater depth earlier, but I was in a hurry earlier. I've never had an airplane buzz this much (or at all truthfully), and now that I know its NOT normal (due to contradicting opinions) Ill find some way or other to correct it.

Thanks for the help, by the way, Ill be sure to check out the seaplane forum

-Kevin

Sturdy:

OK, I feel better now. [8D] You sound like you have it under control.

Here's a little unsolicited advise. Don't wait until you save up the money for a 7CAP. Get yourself something like a Hitec Flash 5. $150, modern computer and reliable as a stone. You won't be sorry.

Jim

It maybe that the servo arms are hitting the clevis at full travel. If you have them in the closest holes next to the arm retaining screw. In one direction it hit's the output shaft, in the other they may hit the clevis, if the arm is protruding past the clevis, and some threaded portion of the control rod is in the way. Might be a good idea to check this as it could mean a clevis could pop open due to the sideways stress the servo is putting on it.


Just my 2 cents coming from experience.

Pete

I did check for that initially, but I did find out what the problem was. It was the servo's. The ones I had in the stab that were giving me a lot of trouble were JR NES-537's (the standards) they came preinstalled in the plane, because the previous owner didnt want them. I dont know the history, but I know they were old. I took them out in favor of near new (3 flights) S3003 futaba's. Works fine now, no buzz at all! Im assuming that the gearsets (nylon) in the JR's were so old that they developed play in them making the pot not able to sense where the center was.

thanks for the help

-Kevin