Aileron rigging

[Skippydiesel]

I have managed to rig, with the aid of a custom made angle insert, my aileron bell cranks to the required 25 degrees.

Unfortunately I am unable to achieve the 74.13 mm aileron neutral (stick vertical) measurement only managing to get Left 80mm & Right 78.5 mm (this mean that the ailerons are pitched slightly down in relation to the wing). I have resorted to using a digital level/protractor and have had to settle for each aileron being within a degree of each other at neutral and 2 degrees full deflection up/down.

(Flaps, full up, are set exactly against ailerons neutral)

My Sonex Legacy will fly for the first time within the next 10 days (weather permitting) - what does the brains trust think of the above rigging/settings?

[Murray Parr]

This is something I had to play around with quite a bit before I got it close to being right. In the end, the 25 degree angle at neutral had to change a bit, although my cardboard angle template might not have been the best way to measure. I set the flaps first to the plans dimensions, then it was easier to see the ailerons where matching that at neutral rather than measuring each time. I didn't quite get the right full deflections either but fairly close (I have the notes out at the airport).

[Skippydiesel]

Hi Murray,

My (limited) understanding is that the bell crank angle "sets" the differential movement (left & right)of the ailerons and is thus critical for "balanced" turns. I am confident that I have the 25 degrees on both.

Both aileron and flaps are very close in paired movement ie full up is within a degree or two, as is full down. The control inputs should deliver the same result, whichever way the aircraft is turned.

The failure to achieve the 74 mm measurement concerns me - how will it effect flight?

[Kai]

Agreed- rigging flaps and ailerons according to plans is a struggle!

What´s more- when you´re finally almost there and decide to take to the air, you will discover what we all did: it will fly one wing low. Then you will have to decide what kind of flying you will do mostly: with or without a passenger- and when solo; where will you sit: center or to one of the sides (one to two sticks?)

Some grey hairs later you decide to leave well enough alone- now is the time to add the small fairing strips over the flap roots against the fuselage. You will be amazed how much of a difference they make once installed. I have seen many Legacies where they are just not there, people have apparently just resigned.

[Bryan Cotton]

You will be amazed how much of a difference they make once installed.

What is the difference? I have maybe one more flap tweak and that means I was going to install them soon.

Initially mine was left wing heavy when sitting left, and perfect sitting right. One half down on the left flap has improved this, but I think I need one more half turn.

[Skippydiesel]

So anyone like to answer my origional question?

"........... unable to achieve the 74.13 mm aileron neutral (stick vertical) measurement only managing to get Left 80mm & Right 78.5 mm ................. I have resorted to using a digital level/protractor ....... each aileron being within a degree of each other at neutral and 2 degrees full deflection up/down.

............... - what does the brains trust think of the above rigging/settings?"

[Kai]

I´d be surprised if anyone is in a position to quantify this.

Neither wings, fuselage, flaps, nor ailerons are built in jigs: not two airplanes are exactly identical. As long as the threaded parts of the control rods cover the ident holes in their respective spherical bearings when the their control surfaces are initially rigged as close to the drawings as you can possibly get them, you should structurally be good to go. And don´t forget the lock nuts! Check that the rods are free to rotate slightly in their bearings with full rudder deflections.

Aerodynamically only flight testing of your particular airplane will tell.

[Skippydiesel]

Thanks Kai,

Yes all rods rotate, thread well past the witness holes ) and lock nuts tight.

I don't have shortening (aileron up) adjustment left, so thread bottoming out in fitting.

[gammaxy]

Sounds like your problem is you can't shorten the aileron pushrods any further? What about the pushrods between the control stick and bellcrank? What if you cut a little off the end of the pushrod bolts?

Realistically, I doubt you'd ever notice the discrepancy in flight. It will be similar to flying around with an extra half degree of flaps. I'd probably still try to match the plans, though.

[Skippydiesel]

Thanks Gammaxy - I had thought of shortening the "bolts" but its now a big job - would have to remove the wings.