Moving the clevis closer to the hinge line (which is the effect of moving inwards a hole) means that the rudder moves more for a given movement of the pushrod.

It may be true that you have to re-centre the trim, but that doesn't effect the above.

Think of it this way . . moving the clevis, say 2 feet outwards (if there was a hole there!) would obviously reduce the throw of the rudder, it simply describes a larger circle.

David C.

--"If your hinge gaps are not sealed, seal them. That alone could greatly increase your control surface's performance."

--"They should really only be wide enough to slip a sheet of notebook paper through."

I have been using a T-pin as a means of spacing the gaps to prevent CA from leaching along the length and binding the control. Maybe 1/32". Doesn't the leading edge need enough clearance to allow easy movement as the small flat where the hinge line is cut butts up against the main wing/stab? Or do I need to bevel the edge down to as sharp a point as possible? I usually leave about 1/8" flat to support the CA hinge.

Does the covering need to be top and bottom or would sealing the bottom only with a flap of covering help?

If your control horns are properly placed on the control surface, where the holes in the control horn line up with the control surface's hinge line, you should not have to adjust the linkage. If they are not lined up with the hinge line, then you probably will have to make an adjustment. When installing control horns, you should try to make the holes in the horn line up with the hinge line of the control surface.

Mike

On control surface gap, the best amount is 0, zip, none, nothing, not a sheet of paper, nada

You don't want ANY air taking a "short cut" from one side of the surface to the other, espeically on the ailerons. Air will go from the high pressure under the wing to the low pressure above it any way it can.

Take a bit of covering or packing tape, and seal the gap.

The easiest way to do it is from the bottom of the wing with packing tape or heat-shrink covering. Disconnect your control rod, and force the control surface as far as it can move, opening the gap as far as you can get it, then get the tape or covering strip as far up in the hinge gap as you can, and stick it really well to the aileron and the TE of the wing.

You only have to do one side, top or bottom, and it doesn't have to be pretty. As long as it doesn't make the surface hard to move.

Sealing the ailerons will also make your trims stay better, reduce the possibilty of flutter at high speeds, and reduce trim changes with airspeed changes.

On anything beyond a trainer, it's a no-brainer, seal the gap

True, but on a trainer, there are better things to worry about!

Hinge gaps are scarcely an issue when flying a trainer.

-DC

ok back to the main question. i took the eye on the aileron control and lowered it by ten turns down (inwards) and it did give me more throw and now the alpha will roll a little quicker. its still a trainer so its not going to do rolls like a magic would. waitting for wind to die a little so i can get my h9 cherokee out , its a virgin so i dont want to fly in a big wind gust yet.....spooner

Ah! I get what you mean now.

Screwing in the clevis doesn't increase the throws, i just adjusts the centre point.

Moving the clevis pin inwards to a hole nearer the control surface increases the throws.

-DC

yes, and in my case the alpha doesn't have control horns but threaded eyes that the clevis hooks to. but same out come..

I think the control horn is what is mounted on the control surface. The control rod has the threaded end that the clevis screws onto.

I know increasing my throws on the alpha didnt make a huge difference, but it did help. I could ALMOST get it to hold a knife edge. I love that plane, wish I didn't sell it. I have a Aresti 40 now which I like, but everything happens so fast you really have to pay attention to what you are doing. On the alpha I could just relax and fly.

On sealing hinge gaps, David Cutler said:

True the vast majority of the time. But I've seen some amazing things show up at the field, including hinge gaps over 1/8"

Back to contorl throws,

new2this, some airplanes have a threaded rod that sticks up from the control surface, or a threaded torque rod instead of the plastic triangle with holes in it. In that case, you would "screw in" the plastic bit to increase the throws.

thank you montague i could not remember the name (torque rod). thats why i love this site.....spooner