I was reading some reviews on a GP Spacewalker. Some of the reviewers were favoring using 2 servos on a split elevator system. They felt the redundancy would help save the plane if one servo fails. I was planning on doing it to my Spacewalker but the tail area looks a little small for two rods. The manufacturer's plans have you assembling a Y system that seems to work just fine with one servo.

Any opinions on this ??

Thanks,

Gary

PS: I posted this same question on the Giant Aircraft Forum.

This is not a plane that you're gonna be putting thru high G maneuvers, just go with a single high torque servo.

I agree with Stickjammer,
I have this plane and love it more than any thing,
It doesn't need it and might make it more complicated
You will need to ad about 2lb in the nose. But thats OK it has plenty of power
and flyes really nice,,, I call mine Speedy Terrisa!
Just trust me on this
One more thing,,, the cowl is not fuel proof so be careful

I don't like Y pushrods in general, so I'm setting my GP Spacewalker with dual elevator servos. My experiences have been that a dual elevator setup can actually be simpler to install and setup. You can match up the control throws very easily, especially if you have a computer radio.

I haven't decided whether to mount the elevator servos up front or near the tail. It will depend on how the plane balances out with the G23 I'm putting on the nose, in place of the Magnum 1.20 4stroke originally fitted.

Two $25 servos typically have much more torque than one $50 servo.

Ya well if it turns out OK let me know..!

I moved all my Servos as far forward as I could and I put
2 1\2 lb of weight in it still,, . the plane is still really light
but if you were to add servos in the tail it might not be so light
Great planes are so good because they are light...
P.S. Hope it works out for you

Hmm... did I not say I was going to wait till I see how the plane balances out with the engine before mounting the servos? You guys are really good at jumping to conclusions. To date, I have not had to put any lead in any of my engined planes yet - and I've built/assembled quite a few. The servos will go where they need to be to balance the plane.

BTW, the G23 I have has CH electronic ignition and weighs just a bit heavier than a typical 1.20 FS glow engine with engine mount. The extra noseweight should come in handy in balancing the plane, as the GP Spacewalker tends to build tail heavy.

One more thing,,,
If you made the tail any lighter it would be paper, haha
its because of the short nose not the tail,,,

IMHO, two elevator servos are unnecessary.

Mine does everything it should do with just the one.

It also balanced perfectly with a YS91FZ up front. It's a great flier!

Thank you Crash_and_Burn!
I couldn't of said it better.
P.S. With my O.S. 91SII 4Stroke it will hang on the prop.
This is only because I had the smallest amount of weight in the plane
and that means not adding tail servos...

Well, I guess using dual elevator servos is more or less a matter of personal preference.

"Unnecessary" is a relative term. Practically speaking, the power of the YS91FZ is unnecessary for this airplane, as I've seen GP Spacewalkers fly just great with OS FX61. But I bet the YZ91 pulls the plane all over the sky.

BTW, I noticed Gary cross-posted this thread over in the Giant Scale forum. Everyone in there are in favor of dual elevator servos, while most here are against it. Kinda shows you the general difference in opinion of the two groups. May be I should go post over there, huh?

Paul, didn't you say you had to put 2-1/2lbs of weight on your plane to balance it?

I'll tell you what Duel elevator servos are,,, They are a fad
And if you don't have em you arn't in the high class group
so Volfy you can have your possibly heavy plane, i'm just glad mine is
always going to fly like a light 3D scale plane!

Yes Volfy 2 1\2 lb in the nose.
Enjoy the Space Walker its a good bird
Paul

Thank you for the commentary, Paul.

I've got 2 servos for the elevators, and it was very simple, and reliable. But neccesary? no, not really. But hurt it? Not even.

Oh, and 2 1/2 lbs of lead? Something VERY wrong with that plane! Saito 91 pulls mine great, and 5 cell batterry under the tank mine is just perfect balance w/o added weight!

JMO

Well. I know that O.S. is lighter and
your engine might be farther forward too.
One more thing, Do you have a Different engine mount?

No, it's the stock engine mount. As far as more forward, that is determined by the cowl. But as far as weight in the nose, I'm not saying zero weight is the only answer, but 2 1/2 lbs?

Any way, the real question is about El servos. Do what you want, this plane will really act the same either way.

I added servos for the elevator as I figured I needed to offset the extra weight of the Enya 120R in the nose, over 2lbs of engine. With the 2 servos in the rear it balanced out just nice.

I had to stagger them with one in front of the stab and the other behind the stab as there isn't enough width to make the servo installation flush. I also did it this way to keep the elevator pushrods level. The problem I ran into was once I put them in there wasn't enough clearance to get a pull-pull for the rudder or the regular pushrod in there. So I had to put another one in for the rudder.

End result was I had to add 4 oz of weight to the nose. I did put the rudder servo under the elevator servo in front of the stab and on the opposite side of the cylinder head to try and maintain lateral balance. Enclosed is a picture of the final result with the two in the rear on the left side.

Enclosed is a shot of the other side with just the one servo.

I put my 2 elev servos sise by side in the regular mounting location (lighter engine) with the pull/pull rudder in between and raised just a little. The trick here was to cross the rods (dave brown glass rods) to get a straight shot. Worked really slick.

I upgraded all hardware to 4-40 to be "legal" for IMAA, I feel sorta silly now, noone else does it and the plane really only needs the supplied gear. I even used high torque servoes, but those are headed to a new home now, and standard servos are going into the SW.

I have to agree with the one elevator servo camp. Mine flies great. Pete

Alright thebluemax,
That isn't even Great Planes is it?

yes it is the GP Spacewalker. I just painted the turtledeck with some green as there a 6 guys with the same plane. Just imagine all of them in the air at once......

Oh . OK ,, looks good for yellow and green