Aileron Balancing and Rigging (3)

3 hours

Before I got too far into setting up the ailerons, I figured I should balance them according to the plans.  This just involves hanging the ailerons by their hinge pins and drilling to the lead weights until they both sag the same amount.

I hung the ailerons from the ceiling with safety wire, and set the tops of the hinges as level with each other as I could.  As far as I could tell, they were within 1/4" of each other.  The plans say to get them within 1/2" so I think this is good enough for now.  If I paint them later I'll have to balance them again anyway.

Next I assembled the two pushrods to the RH aileron.  The short pushrod calls for a custom length bronze bushing, which you have to grind down from a longer piece.  It was pretty tedious but eventually I got a pretty good fit.

My process (mostly for my own reference when I do the LH one), was to ream the end of the pushrod to 5/16" (pretty much to remove the paint), ream the bushing to 3/16" in order to accomodate the bolt, then grind the face of the bushing down on the bench grinder.  When I got it to about 0.010" of where I wanted it, I finished it on a piece of sandpaper to make sure it was flat.

Here's the bushing about halfway through grinding.  I took it from 0.500" overall length to about 0.275".

The plans have you put the bushing through the hole in the pushrod, and then through a flat bronze thrust bearing, with a protrusion of 0.005-0.015" once the bolt is tightened down.  This is about 0.012", which I called good enough.

The other end of the short pushrod attaches to the aileron like this.  The specified bolt (AN3-10) was a little long, so I had to add two washers.  If I can remember, I'll replace this bolt with a shorter one later.

Here are the pushrods finally attached to the bell crank.  The long one goes to the left in this picture, where it would enter the fuselage.  The short one goes up to the aileron.

Here's a video of me moving the aileron with the pushrod for the first time!