Step 7.2, Hanging the ailerons

I thought I would move on to the wing tips now the that bottom skins are firmly attached.

Well, that is what I thought, but it seems that I'm not quite ready for wing tips because the exact position of the tips is determined in part by the "in trail" or neutral position of the ailerons.  That is, that the end of the wing tip nearest the aileron trailing edge must match when the ailerons are in the neutral position.  To make that adjustment, the ailerons have to go on the wing first.

In the photo below, the wing is on the right and upside down on the work table.  The aileron is on the left.  The aileron actuator push tube is visible at the bottom of the photo. 

The ailerons hinge on AN3 bolts through the aileron bracket (white) and through the aileron to wing attach brackets which contain the ball-swivel type bearing that does the actual hinging.  The bearing is not visible in the photos because it is inside the attach bracket in the center of the photo.

Getting the ailerons attached to the wing is a bit of a fiddly process because of the many small washers and spacers.  Fortunately, there are tools to help.  The wrench looking things on the left are washer holders that are very useful.  The washers snap into the end and permit the washer to be held firmly while it it slid into position.  The do dads on the right can be used temporarily in place of a AN3 bolt.  These are nice when a lot of test fitting is required because the ends are not threaded.

With the aileron hanging on its hinges it is now necessary to make the adjustment for neutral position.  The position is set by first securing the bellcrank to its center position using a Van's supplied jig,  W-730.  This jig keeps the bellcrank in a known position so the the aileron actuator push tube can be adjusted for length.  The ball-end bearings on the push tube ends can screw in or out to make the final adjustment.  The end of the push tube is visible in the first photo.

So changing the length of the aileron push tube moves the aileron up and down, but how do we know that it is in the trailing or neutral position?

Fortunately, Van's has provided tooling holes in the wing ribs that are aligned to the cord line of the wing.  A jig is constructed that extends this line rearward when bolted through the tooling holes.  At that point is is a simple matter to adjust the actuator arm until the aileron is in the neutral position.

I've drawn a center line on the inside edge of the jig that bisects the attachment holes in the alignment jig.

And the aileron is adjusted until the center of the trailing edge is brought to the line.