Futaba 9351 servos?

[ericb]

Is there any reason to not use 9351 servos on my elevator? On a Dietrich Extra 260 50CC.

[Mithrandir]

What is the torque?

I used two per elevator on my SX for a long time.
(I think they were 9351's)

[ericb]

193 oz and .13 for speed.

[BTerry]

Yes. You won't be "cool" like everybody who uses JR and Hitec servos and your friends will laugh at you.

In real life, however, you will be just fine. Futaba makes EXCELLENT servos, and this one will be very good in your plane. These are very fast servos relative to their torque, and the torque is high as well. I think Futaba servos are not as popular because they are a bit more expensive than the others, but the quality is evident and you get what you pay for.

Of course if you have not yet purchased the servos, the JR 8711 and Hitec 7955 are about the same price, +- $10 or so, but are both slower (although they have more torque).

[ericb]

I already have them. My elevator will be made fun of by the hitec servos on the other surfaces. Maybe I could put a hitec sticker on them to make them feel better.

[BTerry]

Don't disparage the Futaba servos by cursing them with a Hitec sticker!

Just kidding. They are great servos and durable as well. Imagine JR resolution with Hitec geartrain durability.

[bdawg]

That servo is not for airplane use. That is why they came out the 9155. Those of us that initially used them in planes had them start "jittering" at nuetral after a short period of use. It also caused the gear wear to be excessive because of that condition. I sent mine in to Futaba and they basically converted them to a 9155 at no cost to me.

You might try them and get away with it, but there's a good chance they will start acting up.

Allan

[ericb]

What makes a servo for "airplane" use?

[ericb]

Could I just buy the gearset for the 9155 and make it for "airplane" use?

[ericb]

According to Futaba's website, they are fine for airplanes.

[BigBird]

	Quote: Originally Posted by ericb
	Could I just buy the gearset for the 9155 and make it for "airplane" use?

The gears are the same for a 9351 and 9155. Its the deadband that causes problems in the 9351 when used in an airplane. The weight of the surface causes them to jitter out of control around center. In a car this tight deadband is wanted to keep bump steer from happening. Helicopter pilots love the tight deadband servos also. I would either send the 9351's in to Hobby Service and have them modify the deadband adjustment for aircraft use. Or if you have a .50 or .90 size helicopter put them in it.
Jason

[bdawg]

It's not the gearset but the amplifiers that control the deadband. This is where we were confused when we started using them. Futaba's little chart says they are "compatible" but not "reccomended". I don't know what the difference between the two is suppossed to be but the 9351 is not a dedicated airplane servo unless they changed something in the last three years. I believe that if you go to Tower Hobbies and look at the spec sheet it won't mention airplane use.

If you are using it on the 50cc plane you might have better luck than we did on the 40%'ers.

[Dan767]

I actually used these in my H9 Edge 540 for ailerons and elevators. No jitter on the elevator, an occasional jitter on the aileron because the two servos fought each other because of the narrow dead band. Since the original poster says he is using them on his elevator, I would try them. More than likely, since he's not using them on the same control surface, the jitter problem shouldn't be an issue.

[BTerry]

I was thinking of the 9155 not the 9351. Sorry! Too many numbers to remember.

IIRC the difference is the car servos have very tight deadbands, hence the "jittering" while fighting to find center. What transmitter/receiver do you use?

In the air, when the dead weight of the leevators is not supported by the servos as on the ground, the jittering should not be a problem (they shouldn't jitter with aerodynamic forces on the surfaces).

[ericb]

I have an X9303 with the 921 receiver.