I have a DP extra and am putting a JR 8411 servo on the inside (closer to the fusalage) of the aileron and am putting a JR 811 on the outside of the aileron. The 8411 has 155oz. of torque and the speed is .18. The 811 has 55oz of torque and the speed is .18. Both are digital.
I want to know whether I should use a Y harness on the two servos that are on the same surface (aileron) or whether I should make one a slave and the other a master on the radio?

Hi,
Personaly i wouldnt mix different types of servos on the same surface, i know theyre digitals so you may not have this problem but trying to get two servos of the same model to follow each other can be a task in itself....know from experience.
What are others thought on this?

Happy flying

Willy:

There is a very simple solution to your problem: Don't.

Enough difficulties will manifest themselves without your adding troubles of your own making.

Multiple servos on a single surface should always be the same brand and type.

Avoid simple problems - the complex ones will keep you busy enough.

Two servos per aileron or flap,
. Mix 'em up your head you should slap.

Bill.

Dave Patrick told me to use one high torque and one mini he said that they did not have to be exactly the same speed but close.

what can go wrong if i use two different servos?

Willy:

If you have a programmer to match the pair acurrately they'll work. Matching includes the angles at several different pulse widths. Any mismatch will result in one servo fighting the other, and running your battery dead. It's just safest to have a complete match, including brand and type.

Your airplane. Your money. Do as you wish.

Go ahead, run your battery flat.
. Your plane'll go in, and that is that.

Bill.

I just deceded to go with one servo for each aileron it will be 122 oz for the DP EXTRA. what do you think. I already ordered my servos. I hope this wiil be enogh. I can always add 2.

LC:

Multiple servo use has a couple justifications. Sufficient power is only one. Others include the flex of the control surface, the possibility of ripping the control horn off under high aerodynamic loads, (two horns are stronger than one) and of course, the old standard, redundancy. One fails, the other will help you get it home.

Friend of mine had his 60 stick out weekend before last, said it felt funny in roll. Right. When he brought it in we found his right aileron servo was dead. This was, of course, only one servo per aileron but the redundancy got him home with an uncrashed airplane.

Single heavy servo is OK up to about 100" span, but I personally use four wing servos at 80" and larger.

Have fun.

Two servos or four,
. Build a twin, it'll roar.

Bill.