SBarber

I have a new Somthin Extra ARF. The directional trim changes as I speed up. I've tried making sure the ailerons and rudder are correctly adjusted. If the trim is set a low speed it takes three clicks of aileron to correct the turn tendancy at full speed.

Does anyone know what I can look for to correct this?

Thanks, Steve

bubbagates

My Feedback: (32)

Steve,

I really hate to answer a question with a question. What kind of control rod are you using on the rudder. If my memory serves me, the stock control rod for the rudder is nylon and in the hot FL sun can get somewhat "soft" and has been know to change trim. Now, at speed if you have any amount of rudder trim, then the control rod could be flexing enough to "re-center" the rudder enough to make the plane be out of trim again.

If I am correct on the control rod, then I would suggest replacing it with metal. Depending on the engine/prop combo, an SSE can really scream. Mine had a 46AX from OS and an APC 11X7 and the thing had a pretty fast top end to it but the other thing is it wanted to climb at full throttle but that's normal.

MinnFlyer

My Feedback: (4)

It could also be a matter of lateral balance:

If one wing is heavy, that aileron will have to droop slightly to hold the heavy wing up - But the faster you go, the more air you have pushing that wing up, so it can cause more lifting of that wing.

SBarber

Bill,

I also have a 46AX but am using a 11x5 prop. All the control rods are metal and the rudder is trimmed straight al low speed. I will check the lateral balance tonight.

Steve

bubbagates

My Feedback: (32)

Yep, I'd then go with Minn and check lateral.

The 11X5 is just fine, tons of pull and not allot of speed. Even still on high rates, full throttle with the 11X5 the roll rate is phenomenal.

kdheath

Check the wing for warps, too.

SBarber

Well today I checked the lateral balance and it's right on. I looked at both wing halves and they seem to be straight. After doing a thorough inspection I did discover that one of the wheel pants is not perfectly straight. I will take them off and see that helps and will let you know.

Steve

SBarber

This weekend I took both wheel pants off and the problem remains. I have checked everything I can think of twice with no luck.

1. Took off both wings and laid them side by side on a flat table with a straight edge on top, both are straight.
2. With the wings on I put a square where the wings meet the fuselage and the fuselage appears to be straight.
3. Checked and re-checked the aileron placement with the provided guide.
4. Checked rudder and horizontal stabilizer and they are square.
5. Checked lateral balance and it's OK.

Still the plane requires three clicks of aileron trim at full speed versus no clicks at slow speed. Also noticed that even though the high rates are set per the manual the roll rate seems to be much slower than other somthin' extras.

Any other suggestions of what I can check. This is getting frustrating.

Thanks,

Steve

MinnFlyer

My Feedback: (4)

Interesting...

Is there any engine offset built into that thing? And if so, is it correct?

As for your roll rate, are your gaps sealed? If not, seal them.

SBarber

There is engine offset built in, how do I know if it's correct?

Steve

krossk

My Feedback: (27)

Since SSE has separate wing halvs with a locating pin, is it possible that the wing halves are not set at the same incidence angle?

RCKen

My Feedback: (9)

I had similar problems with my SSE, in that it would change trims while flying. My problem was that I had flown the plane too much. I know that sounds silly, but it's true. I had flown it so much that the holes in the fuselage had wallowed out. One of the wing tube holes and one of the wing alignment holes had worn out which allowed the wing to shift and move around while flying. This is what caused the trim changes on my plane. Check these holes and make sure there is no slop in them. Grab the wing and try to move it around and see if there is any movement. There should be no movement at all.

Hope this helps

Ken