Has anyone rigged a biplane with S-Bus aileron servos? If so, how did you set it up? Do you use four channels to set sub trims and throws in the transmitter or program the servos or both? Is there a better way?

Jim O

Hello there. While I have not a bipe, I do have a number of S.Bus models including 2m. After setting mechanical linkages on a new model, I fine-tune the centering in the servos. After rounds of trim flights, I program the resulting trim into the servos so that there is no sub-trim, and little to no trim on the radio. This in my mind minimizes the problems if one were to take off on the wrong model, and eliminates the possibility of reversing ailerons as the channels are also programmed into the servos. The single S.Bus cable per wing is a big convenience for a bipe I'd imagine; and I enjoy it on two scale sport monoplanes with single piece wings. The other nice thing is that if one is re-trimming during a flying session and wishes to discard the changes, just go back to zero.

P.S. On a bipe, I would probably just stick with my usual Ch.1 for the left, and Ch.6 for the right ailerons; bipe guys may recommend otherwise if there is an advantage to 4ch.

I do have that setup in my Acuracy Bipe,

Wing Type set to 4 Ail 2 Flap
Stab 2 stab

I programmed all the servos to respond to its Function channel, it does not matter if you program a servo to a channel, if connected to a regular channel it will work as a regular servo, as on every start up the servo identifies the signal it receives and selects itself the method of operation.

ch1 Ail
ch2 Ail2
ch3 Ail 3
ch4 Ail 4
Ch5 Rudd Regular Ch
Ch6Elev
Ch7Elev2
Ch8 Ign Regular Ch
Ch9 Thr

I have each wing with both ser with one connector (soldered instead of Y), Then a Y to connect both wings
It works really well, so I cannot tell any difference as with a regular setup, but saved weight in extra leads not being needed.

Regards

Alejandro

Thanks guys. I like the four channel setup. Looks like you can mix S-Bus and regular servos. Perfect.

Jim O

Hi Alejandro,

What does ch8 Ign Regular channel do?

Thanks

Keith

Hi Keith,

It is for the Emcotec Ignition SW, it does work only on regular channels.

Regards

Alejandro

Jim,

I'm planning on using SBUS in my biplane as well... rather than using 4 channels for ailerons that Alejandro is using, I plan to use 2 channels and I will program the centering directly on the servos and also the max throws so that they hopefully will all match. Since my rudder servo and 2 stab servos all sit in the rear of the plane, I am also only running 1 SBUS hub cable to the front versus 3 separate servo extension cables. Saves weight and clutter.

Derek,

It might not matter, but you will find that you can set the sub trim and maybe the travel, more accurately in the transmitter, (one part in 2048). It has been awhile but I remember that the servo could not be programmed that accurately (.25 degrees?). Therefore the four channel approach might be better.

Jim O

Hi Guys,

I went the four channel way just in case as it is my first byplane with SBus, and as I soldered both servo wings together I wanted to make sure I could make changes without reprogramming the servos, but as Derek is planning, I programmed each servo individually as the Acuracy uses max servo throw on the ailerons, but I programmed each servo(all), for example on the rudder I set the max throw on the servo, and as the servo keeps the programming it does not matter if it is in a regular channel, so I cannot exceed the throw no matter what I do with the transmitter programming.

On the four wing setup all trims and mixes are authomatically programmed.

Regards to all

Alejandro