Flyfalcons

I am putting together the radio installation for my new plane, and I have two elevator servos. When using the DuBro servo arms, one arm will center on one servo and the other arm will be a few degrees off perpendicular in either direction. Using sub-trim to correct this, I am finding that upwards of 50 percent is necessary, which will severely limit the full range of the servo travel. Is there any way to get the arms to match up without using excessive sub trim?

CAP232CM

My Feedback: (8)

First of all you need to determin weather it's the arm or the servo at fault. Try switching the arms from one servo to the other, if it's off the same then the servo must have a different centering point. If this is the case you might have to get a different servo that matches up better.

Also need more info. Are you using a miricle y with an ajustment pot or a regular y harness? How are your servos mounted in the plane?

Flyfalcons

No Y-harness; different frequencies. The problem is that with both servos (actually all four that I have), the arm will be perpendicular in one direction, but off in the other direction. The problem comes from the arms needing to go in opposite directions, and the servos have the same centering point. As of now I have sub-trimmed each servo around 22 points, so the effect is not as severe. However, it is certainly not desirable.

pwood

Hi. A normal servo arm needs to be tried in all the possitions as each one of the , say 4 or 6 arms do not line up the same as the other one. When you try it, it is so easy, try pos. 1 as close to centre as possible, then try pos. 2 and you will see it is a few degrees off, and carry on until you find the best possition.

Most people cut off all the arms except one and then try fit it to the servo. You should try all the possitions and then cut the ones you don't want.

The Dubro ones are a bad idea because you can't do this. I have never tried them , you might find that each arm is slightly different. Try them all on one servo and see. Futaba arms are not the same, some times i try 3 or 4 arms in all 4 positions before one lines up propperly.

Paul

Flyfalcons

I agree, the normal servo arms are nice because you can rotate them until youfind the perfect arms. It took me a couple planes before I realized that. The problem with the DuBro arms are all exactly the same, which creates a problem because there are an odd number of teeth on the servo. One direction will be perfect but the other will be off. There is the opportunity to take each of the two-sided arms and cut them in half, but I have already used them on the ailerons and I need longer arms for the elevators anyway. If there is a way for the user to adjust the servo pot then that would be ideal.

JetAwithPrist

What kind of servos are they?

Flyfalcons

JR 4131

JetAwithPrist

sorry i dont know, if it was something i had i was gonna take a look at myself.

I GOT IT! i'll trade you some REALLLLLLYYY nice tower hobbies servos for them, then you wont have to worry about it. lol