Does anyone know if there's a way to adjust the centering of a servo? I'm using Hitec HS-425BBs in a Kaos, and when I attach the servo arm to the servo, it's off one way or the other when the servo's in a neutral position. Since I have a single aileron servo, this biases the ailerons one way or the other. Thanks for any suggestions.

7ECflyer

By rotating a 6 point servo wheel, you can adjust that. Notice that each arm is numbered. Rotate to the next number and it will be off slightly from the previous one:

That only works on Futaba as they have an odd number of splines. You can rotate an arn 180 degrees and it will offset by 1/2 spline because it is odd.

Hitec has an even number of splines so this does not work. This is my only complaint about Hitec servos.

Ov course with a computer radio, this is not a problem as you can adjust the center in the radio (without affecting the trim control.).

JR spines are odd-numbered also, so you can get 1/2 spline adjustments. But in re-reading the original question, a slight angle off dead center will not have much influence on your set-up, and you then adjust the klevis at the control horn end to center the aileron.

Clair

Here is the deal. I ask this same question when I first started using Hitec items. I ask here and also at Hitec. I got the same basic answers. I can guarantee you this works...... at least it has for me. Beg, borrow, or buy, the type of arm you want to use. Get a BUNCH of them. Now start picking up one at a time and place it on the shaft. You WILL find that some will be dead on, and some will be as you said, off center a hair.
I have done this with their heavy red arms, and 4 point arms in white nylon. I am sure it will work on all their servo arms. I found that about 1 in 4 seemed were good. Of course that is just the group of parts I had. It could be better or worse..... but you WILL find some good ones. I have almost all Hitec Rx and servos, and am very happy with their products. But that is the one thing that irks me!! I have never had that problem with Futaba. .....lownslo...

So buy Futaba servos...

Yuk-a-yuk.... that was a knee slapper!! Seriously.... some of us out here are retired, and don't have "unlimited" resources. I went to the Internet Fly In last year. That was my first real fly in, and I saw some very "well healed" people flying some very nice eqipment. I don't fly junk,
and all my planes and equipment are well kept. But, if I can save about $20 to $25 on a flight pack and standard battery, I will stay with Hitec. Hitec includes the battery and Futaba doesn't. (remember my post.... I found a way to center the Hitec servo arms....... and I don't like/trust, the R127DF receiver that comes with the comparable Futaba flight packs). Don't get me wrong....... I think Futaba is probably the best radio equipment overall. (I have 2 planes with Futaba PCM receivers). Hitec gives you good "bang for your $buck"[8D] .... lownslo....

The point at which a servo centers is determined by the placement of the body of the potentiometer inside the servo. If you absolutely must change a center, open the servo case and rotate the pot body by the amount you want to change the centering. Just make sure you dog or glue it down afterwards or it could rotate and change center position in use. When a servo is manufactured, the minor differences in tolerance build up makes an exact duplication in all servoes next to impossible.

You didn't mention the transmitter you are using. Can you use sub trim in you transmitter? I will put the arms on as close to center as I can get then use a protractor and adjust sub trim to get them exactly center.

DEG

Thanks for all the replies. I'm using a Hitec Flash 5 transmitter, and I don't think there's a way to trim the servo centered without limiting the maximum throw. Like Lownslo, I found that all of the Hitec servo arms are different, I just couldn't find any that were quite right. It's too small a problem to take the servo apart, so I'll live with the bias on the ailerons.

7ECflyer