Jumpy Futaba 9254

[deputydog]

I put a Duralite regulator (6V) in my TRex600 with a stepdown to the tail servo (FUT9254). It seemed OK initially, but now it jitters constantly. I checked the voltage and found 5.78V at the tail servo lead with the step down installed and 5.77V with a 1amp load. Duralite sent me a new stepdown and now I have 5.3V at the tail servo with it running, but it still jitters the same.

I put old reliable 4 cell nicad pack on and it is fine. I also hooked up my 9254 from my Raptor and it jitters with the regulator/stepdown and is fine with the nicad.

Seems like it must be the voltage, but I see lots of posts saying 5.3V is fine for the 9254.

Running Spectrum w/ 9451's for head, 9550 throttle, 9254 tail w.Gy401

Could it be noise in the regulator? Any ideas are appreciated.

Thanks-

[deputydog]

Put a 2-in-1 regulator in that I had with the step down and still doing it. Put the Nicad back in and now it's doing it with that also.
Could the 5.7 to 5.8V have damaged the servo?

Now I are confused!!

[DavidH]

I have used a 9254 on regulated 6 volts. 5.8 volts has not damaged the servo. The step down is nothing but a resistor. So it should not be causing any noise.
David

[Rappy_60]

The step down is nothing but a resistor

Try a diode, not a resistor. The step down is nothing but a diode, it provides a .7 V drop for a silicon diode, and .2 volts for a germanium diode. Therefore if you are powering the tail with 6.0v then you can expect 5.3 volts to the tail servo with a regular silicon diode (.7V drop).

Dale

[BarracudaHockey]

Try another servo, its possible running it at the higher voltage, especially if your setup was not optimal in terms of linkage and gain, that you did some damage to it.

[Rappy_60]

My guess is that the motor on the servo is done. I have had a similar experience with the 9254, sent it into futaba service, they sent it back telling me it was repaired and that they tested it "extensivley". Pluged it in and same problem, very twitchy. Sent it back asking them if they even opened it up and tested it. They sent a new one with a note telling me it was the servo motor.

Dale