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Digital Servo Buzz

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Old 08-16-2006, 05:56 AM
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MaJ. Woody
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Default Digital Servo Buzz

Hi.
I am using digital servos on all my flying surfaces and noticed that some servos continually buzz. As I understand it, this is the digital servo try to find center. Will this constant buzzing burn out the servo? I know it will drain my RX Pack.

Thanks for the help!!
Dom
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Old 08-16-2006, 08:36 AM
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BarracudaHockey
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Default RE: Digital Servo Buzz

Digitals buzz, thats the nature of the beast, I dont think they will draw much more current at idle than analogs but they update the motor position many more times per second than analogs so you do get increased current flow especially under load.
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Old 08-16-2006, 08:48 AM
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Edwin
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Default RE: Digital Servo Buzz

While we're on the subject. I've seen digitals (in addition to the buzz) oscillate. The control surfaces were flapping away until air pressure was put on them. Is this normal also?
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Old 08-16-2006, 11:44 AM
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Default RE: Digital Servo Buzz


ORIGINAL: Edwin

While we're on the subject. I've seen digitals (in addition to the buzz) oscillate. The control surfaces were flapping away until air pressure was put on them. Is this normal also?
Edwin
Its not a good condition. It puts extra strain on the gears and runs down the battery. There could be several causes for it.
1) Linkage binding - Free up the binding.
2) Heavy control surfaces - Static balance the surface.
3) Servo deadband too tight - If Hitec servos open the deadband with the programmer.
4) If two servos are hooked to one surface they could be fighting each other - Match the servos.
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Old 08-16-2006, 12:19 PM
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Edwin
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Default RE: Digital Servo Buzz

Wasnt my plane. It was a giant 182 with JR servos. This particular plane crashed a few months later. Young pilot couldnt figure out what happened. Was obvious to me, nose high stall and not enough air over the control surfaces, pilot error. I dont think it had anything to do with the oscillating I saw on the elevator earlier. But I COULD be wrong. Thanks for the info.
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Old 08-16-2006, 02:04 PM
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Default RE: Digital Servo Buzz

JR servos are set up with very tight deadbands. Once the potentiometer gets a bit worn or the gears get a bit loose they will do the flutter you described. Its probably not the cause of the crash though. The flutter will stop once there is a load on the servo as you observed. It could drain the battery quickly.
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