hi all,

i'm trying to decide on a elev. hookup for a Su-31 69" span.

a) 2 servos at the tail (short linkage)

b) 1 stronger servo at the mid section & a splitter (one push-rod going to the tail for each elev. half)

the weight in the tail is NOT an issue since i am moving the rudder servo upfront (pull-pull) and the smoke hookup using a separate battery & ST 2300 engine will provide enough ballast up front

the only issue is to have independent elevator control (possible mix) OR a hidden servo with a splitter for a more scale look

I would love some feedback,
thanks, Vasek

For me it's a no brainer. I'll go with 2 servos in the tail unless the added weight is a no no.

Yeah I'd do the same thing given the description.

Since weight is not an issue, the short coupled control links will result in smoother movement and more accuracy with less slop.

Each servo is likely to have to work less, so there will be less change of gear stripping or other potential problems.

Power draw should end up being almost the same too.

Two servos is the way to go. You can link them with a Smart Fly Equalizer II . It is a very small and light chip that each servo plugs into and in turn plugs into one channel of your receiver. You can individually set the end points and sub trims using the easy to program dials. Only costs around $40.00. I've been using one for the past two years with absolutely no problems.

http://www.smart-fly.com/Products/Eq.../equalizer.htm

Same-Separate Servos. If one of them goes out, it'll be a rough ride but the odds are in your favor

Yeah servo failure is another good point.

Careful with the syncronizers though.

The Smartflyer posted above is interesting because it may be doing everthing digitally or discreetly in terms of generating the servo pulses. The trimmer seems to be used as a positition switch.

I have a cheaper servo adjuster, that has an on board crystal and POT.

I tried it once, then threw it away.

The crystal is subject to temperature changes, the POT is not very accurate ( and the carbon will wear under the sweep arm ) this means that you would have to adjust the syncronizer every time you go to fly... and after awhile you would have a hard time getting the two servos in perfect sync.

It was far more hassles than it was worth. I ended mixing the tail servos on the TX.

Ok. 2 servos in the tail it is.

I will sync. the servos via the TX.

thanks guys,
V.

.

I said nothing NEGATIVE about the Smartflyer.

I commented that the way the circuit board was set up was "interesting" in that it was doing things in a way which was UNLIKE my experience with the servo adjuster I had used which I had bad experience with.

Flyer, what would be the advantage using the Equilizer over using 2 ch from the TX? (except saving one channel)

You save a channel and it gives you the ability to switch to another TX easily if you need to.

The only MINOR drawback will be SLIGHT additional power consumption.

I do not know how that particular syncronizer deals with endpoint adjustments, but the TX often permits finer grained control as each servo can be adjusted independantly.

On the better TX's you can also bring mixing curves into play as needed to offset linkage differences.