AB Bob

My Feedback: (20)

The last two times I went flying, I have burned out a servos each time. [&o]

Last week, the throttle servo burned out at full throttle, right at take off. I had to fly around at WOT until I ran out of gas and dead sticked it in.
I replaced the servo.

Today, (first time out since the throttle servo replacement), I had one good flight and most of the second, as a matter of fact, I didn't notice the inoperative rudder servo until I was on final, got it down OK.

Could something w/in my battery pack, switch, Rx be causing this? Or just a wierd coincidence?

The servos were Hangar 9 S-300's that came with my Alpha 40 RTF.

The battery pack is a Spektrum NiCd 4.8V 1500 mah that also came with the Alpha.

I replaced the Spektrum AR500 Rx with an Airtronics 8 CH Rx (Sold all my Spektrum radio gear and bought ATZ RDS8000 w/ two Rx's).

All your thoughts are appreciated.

Bob

pilotpete2

I can't imagine a problem with any servo using a standard 4 cell receiver pack. In the case of the throttle servo, there is the possibility that at full throttle the servo was trying to drive the throttle further than it could move, make sure to adjust the end point setting on the radio so that the servo isn't bound up at either end of the throttle range. As far as the rudder, y'got me there[]. I don't know anything about those servos and didn't see them listed on HH's site. If it were me, I'd switch over to Hitecs
Good luck,
Pete

ronwc

My Feedback: (404)

Servo's are normally very reliable - I have some i've have in planes and still fly that are well over 15 years old. If you''ve already had two fail, they are bad servo's, at the very least, I would change out the Aileron and elevator with Hitec or Futaba and save the bad ones for throttle -

Rodney

I've never seen this happen with a properly installed servo. are you sure that, at full throw at either end that the servo is not stalled out? By that I mean that it is being physically restrained from moving as far as it is commanded to. That could and most probably would burn out a servo as the impedance will fall to a very low value if the servo is stalled and cause it to draw excessive current as long as it is stalled or until something burns out.

AB Bob

My Feedback: (20)

Thank you all for your posts.
I have some used HiTec's that I'm going to install.
I don't see or hear any signs of binding....but.
I don't usually go full deflection on my sticks, usually just bump them.
I'm going to replace the battery pack as well. I have a new Hydrimax 2000mah @ 4.8V.
Being these were on my trainer, they have taken a "few" hard knocks...
Thanks again.
Bob