Hello,

Has anyone had any trouble with the elevator set up on this ARF?

My problem is that one half travels farther than the other. The reason is because when the servo arm is nuetral it is at 90 degrees. When the arm goes forward it also moves to the right (looking down on it). This in turn is causing the entire rod assembly (wooden dowl and all) to rock to the right. When this happens it pulls one elevator farther than the other. Same affect on down elevator.

I am starting to come to the conclusion that this set up may not work. I have already glued the hinges on the elevator, so I can't easily add a rod connecting both halves like most planes.

I can make it somewhat better by bending one of the rods. But this does not totally correct the problem and I don't trust depending on a bent rod that could flex in flight.

Anyone have any suggestions?

Thanks,

Matt

Dude .. teach you one simple trick ... try attaching the elevator pushrod clevise at different points on the elevator horn. E.g. lets say RIGHT side travels more than LEFT side. St what you do is to attach clevise to the outer most hole on the RIGHT horn and perhaps a little further in on the LEFT horn. This does help the situation. If you use the adjustable horns you can fine tune it more. Hope this will assist you.

Thanks for the reply.

I thought about doing that, but the thing is it is still not perfect. Correct me if I am wrong, but if both halves don't move exactly the same won't the plane want to roll everytime I apply elevator? This would be impossible to trim because the differential would be different depending on how much elevator I apply.

Maybe I am making a mountain out of a mole hill, but I assumed they had to move exactly the same.

Even if did get it close by using different holes in the horns, it is not linear. The more elevator applied the more it moves the entire pushrod side ways.

or you can put high torque micro servos aft....these pics are of the standard servos I used first ...then I swiched to micros to get the CG right....l JW

Here is a pic of the Micros...JW

Oh man ... this is so dumb of me ... try a bell crank! That might be a nice winter project! A lot cheaper than mini servos and more consistent than what I had suggested first.

I did a variant on the micro servos YS performance has some neat stuff besides engines it consists of a shaft with a center horn
and 2 BB side plates (mounts the same as servos) the arms are connected to the elevator horns via short rods and clevises
the center shaft arm has a 4/40 rod connected to the elevator servo (right down the middle) no slop the dowel stick thing with the
y rods does not cut it, you can also use sullivan tubes and rods and join them at the servo end.I just got a 1/4 scale GP space walker
and they do the same thing, the elevators willl be driven by one of the above methods and the rudder going to pull/pull cables

see previous post

[quote]ORIGINAL: dieseldan

I did a variant on the micro servos YS performance has some neat stuff besides engines it consists of a shaft with a center horn
and 2 BB side plates (mounts the same as servos) the arms are connected to the elevator horns via short rods and clevises
the center shaft arm has a 4/40 rod connected to the elevator servo (right down the middle) no slop the dowel stick thing with the
y rods does not cut it, you can also use sullivan tubes and rods and join them at the servo end.I just got a 1/4 scale GP space walker
and they do the same thing, the elevators willl be driven by one of the above methods and the rudder going to pull/pull cables
By the way the end result looks like autoguns the end pieces look like servo tops

Thanks dieseldan,

The above sounds like the cheapest and simplest solution to this problem.

Have you actually had this set up before?

This will not have any of the "shifting" effect of the crappy dowel rods?

Thanks!

Matt

Wings all you do at the servo ends is use the threaded rod on the end of the sullivan cables and add a 3 rd rod to the two the third rod of course goes to the servo I used 2 wheel collars to clamp up all the rods together I got the idea from a vmar ARF I had that used the same setup with 2mm pushrods thru tubes works great it was overkill but I epoxied the rods to the wheel collars if they really
good and tight really not needed could also ca to fil the gaps \
I think the rod and sideplate thing came for Central hobbies not cheap $30 the sullivan rods are cheaper as you say and a lot
quicker to install
I really do not like the "free floating push rods connected from the servos to the horns on any plane ALL MINE were changed
to rods in tubes (of course most do not have a split elevator) you can anchor down the tubes at both ends and a former half way back
NO SLOP OR BENDING

Have a look at this post. Maybe it will give you an idea or two..

http://www.rcuniverse.com/forum/m_19...tm.htm#1942232

This works extremely well, yielding an unsnappable plane!