servo noise

[kdouglas03]

when i turn on my transmitter and receiver my servos make a highpitched noise what causes that and is that something to worry about

[TonyThomasian]

Thats just because they are digital servos. nothing to worry about.

[Andy Thomas]

Are you running 1 per surface or 2.

[exeter_acres]

	Quote: Originally Posted by TonyThomasian
	Thats just because they are digital servos. nothing to worry about.

My thoughts too, but how do we "know" they are digi's


Which servos are they??

[Kiwi]

KD,
Despite popular myth digital servos should not make high pitched sqealing noise, unless they have some kind of load on them that is.

So if your servos are digitals and on heavy flying surfaces, say elevator, well to see if it is geometry or a bad linkage take the elevator in your hand and lift it very slightly to see if the noise goes away. It should if things are setup right. Same for ailerons, take the weight in your fingers to see if you can get rid of that noise. If it goes away you dont have any problems. If it stays you have some binding or something putting a load on your servos.

Rudder servos should never squeal. With the tail off the ground your rudder servos should not make a noise.

If you have ganged servos then it is truly just adjustment. The difference between a noisy servo and a silent one is the thickness of a knats hair, its nothing. But if you have standard linkages with a continuous thread adjustment the best you can ever do is adjust in half turns. Thats not accurate enough for todays top of the line digital servos. H9 and some others have links with left and right hand threads on each end and these are infinitely adjustable and capable of shutting those screaming servos up.

As a good rule of thumb if your setting up ganged servos go buy a cheap multimeter that can read amps. You only need one capable of five or ten amps. Plug it in series with a battery pack feeding your RX and see what amps your system is pulling in neutral. It should be around 150 to 200 milliamps. Maybe a tad higher if you have a setup with LED lights etc included.

Do that test with your radio on of course. Now go to full deflection and see if you are dragging more current (amps) with the servos at the limits. The reading should still be very close to the same at neutral.

If you have any servos binding or surfaces binding this simple little test will prove it. It is great for ensuring your end points on ganged servos are accurate. Again you often hear models that make no noise at neutral but scream at full deflection. If thats happening the geometery is wrong or the linkages between servos are wrong or the end points are set wrong.

And then after all that if you want to complicate things further and you have HITEC digital servos you can open up the deadband on them. That makes the servo less sensitive to the centering point. So if you have say four servos on rudder then the master servo is set with tight deadband width (say 1) and you set the throw of the servo to the maximum you want. Then the second third and fourth servos get adjusted one at a time and in sequence to match servo 1. But you change the deadband setting to say 3 so that those servos 2,3 and 4 dont fight servo number 1 in neutral.

Sorry for the long blah blah blah here guys but digital servos only squeal if they have load on them.

Kiwi

[TonyThomasian]

Well, he has a DA 50, and most probabaly on that plane, he has digis.

	Quote: Originally Posted by exeter_acres
	My thoughts too, but how do we "know" they are digi's Which servos are they??

[exeter_acres]

	Quote: Originally Posted by TonyThomasian
	Well, he has a DA 50, and most probabaly on that plane, he has digis.

I would hope... but we all have seen stranger things!

[kdouglas03]

yeah i got digi's and the noise goes away when i hold the ailerons

[TonyThomasian]

yea, your fine. dont worry about it.

[LookNatU2]

Good info KiWi, Thanks