What Caused This Servo Failure?
05-16-2022, 10:24 AM
#1
What Caused This Servo Failure?
During approximately 80th flight, this Futaba digital 3151 aileron servo failed during travel, stopping nearly at the end of travel but not quite. Gear train feels good. Programming limits were well short of any physical limit (no binding) and this servo only ever saw 6v. Servo won’t travel in either direction but if I unplug it and move it manually to any point, it holds that point solidly one plugged in again.
I am replacing the other 3 servos in that wing as well now out of caution, but am curious to see if someone here with more experience has thoughts regarding the failure mode.
As always, my thanks for your inputs!
I am replacing the other 3 servos in that wing as well now out of caution, but am curious to see if someone here with more experience has thoughts regarding the failure mode.
As always, my thanks for your inputs!
05-16-2022, 11:10 AM
#3
During approximately 80th flight, this Futaba digital 3151 aileron servo failed during travel, stopping nearly at the end of travel but not quite. Gear train feels good. Programming limits were well short of any physical limit (no binding) and this servo only ever saw 6v. Servo won’t travel in either direction but if I unplug it and move it manually to any point, it holds that point solidly one plugged in again.
I am replacing the other 3 servos in that wing as well now out of caution, but am curious to see if someone here with more experience has thoughts regarding the failure mode.
As always, my thanks for your inputs!
I am replacing the other 3 servos in that wing as well now out of caution, but am curious to see if someone here with more experience has thoughts regarding the failure mode.
As always, my thanks for your inputs!
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Springbok Flyer (05-16-2022)
05-16-2022, 02:07 PM
#5
Different servo (Hitec HS-81) in a different application (aileron servo on an electric model) but exactly
the same failure mode. Thankfully the model has two aileron servos.
It sounds like the same part failed, IC I suspect, nothing else found wrong with it. Like BarracudaHockey
said simply a servo failure, thankfully it doesn't happen too often & sometimes a servo will give you some
warning. My beater model for testing radio gear had the elevator servo not return to neutral in the same
position every time. The important thing is to heed the warning & replace it immediately.
the same failure mode. Thankfully the model has two aileron servos.
It sounds like the same part failed, IC I suspect, nothing else found wrong with it. Like BarracudaHockey
said simply a servo failure, thankfully it doesn't happen too often & sometimes a servo will give you some
warning. My beater model for testing radio gear had the elevator servo not return to neutral in the same
position every time. The important thing is to heed the warning & replace it immediately.
05-16-2022, 02:26 PM
#6
1) Y’all tend to be among the most experienced
2) The servo failure mode needn’t have been jet-specific, or foamie, giant scale, etc…
3) Yes, it’s an inexpensive servo in a jet. A lightly loaded, draggy, under powered, slow jet. Slower than some of the proppies I’ve flown. The only thing “jet” about it is the noise that comes out of the back ;-)
The following users liked this post:
grbaker (05-16-2022)
05-16-2022, 02:31 PM
#8
Different servo (Hitec HS-81) in a different application (aileron servo on an electric model) but exactly
the same failure mode. Thankfully the model has two aileron servos.
It sounds like the same part failed, IC I suspect, nothing else found wrong with it. Like BarracudaHockey
said simply a servo failure, thankfully it doesn't happen too often & sometimes a servo will give you some
warning. My beater model for testing radio gear had the elevator servo not return to neutral in the same
position every time. The important thing is to heed the warning & replace it immediately.
the same failure mode. Thankfully the model has two aileron servos.
It sounds like the same part failed, IC I suspect, nothing else found wrong with it. Like BarracudaHockey
said simply a servo failure, thankfully it doesn't happen too often & sometimes a servo will give you some
warning. My beater model for testing radio gear had the elevator servo not return to neutral in the same
position every time. The important thing is to heed the warning & replace it immediately.
