Ailerons Rigging (8)

8 hours

This was a bit of a process!   Some of it was self induced though I guess,  Anyway I connected the inboard ends of the aileron pushrods to the stick and set about getting everything adjusted.  I started by adjusting the long pushrods until the aileron neutral positions matched the flaps.  That was actually pretty easy, but I ran into three issues.  First, the rod end bearings would run out of swivel travel with the stick all the way back, so the ailerons couldn't be moved with the elevator all the way up.  Next, the stick still ran into the hole in the seat pan before the ailerons ran out of travel.  Finally, the autopilot roll servo pushrod interfered with the long aileron pushrod and one of the seat ribs in certain positions.

To solve the rod end bearing interference, I first tried holding the long pushrod in certain positions as I tightened the jam nuts, hoping to not waste any travel.  That didn't really work, so eventually I went home and made some dished washers like I did for the elevator, and installed them at the outboard bell crank.

The washers helped, and then I tightened the outboard jam nuts first and the inboard ones second, making sure the pushrods were rotated all the way aft with the stick forward.  That made enough room for the rod end bearings to swivel as the stick was pulled aft so they wouldn't bind at either end anymore.

Next, since the stick ran into the seat pan before anything else, I thought there must have been something else wrong.  I decided to recheck the adjustment of the short pushrods.  To do that, you set the ailerons to neutral, and then check that the outboard edge of the bell crank is at a 25 degree angle to the wing rib next to it.  I started by clamping the ailerons to the flaps so they'd be held in the right place.

I made a little 25 degree gauge out of scrap.

To adjust the short pushrods, first I had to loosen the jam nuts, which were inside the wing with the ailerons installed.  I found that I could disconnect both ends, turn the pushrod on an angle, and then I could just barely get at the jam nut from the outside.

Finally I could use my gauge.  I ended up shortening the left one two turns, and leaving the right one as it was.

Then I had to reset the neutral position on the left aileron by adjusting the long pushrod again.  I found that the small adjustment I made on the short pushrod required a pretty big adjustment on the long pushrod!  After all that, the aileron travel was no different, so the only thing left to do was enlarge the hole in the seat pan.

I ended up cutting 5/8" from each side.  Then I carefully vacuumed all the debris out from under the seat and around the stick!  I found that before I enlarged the hole, the ailerons could were able to travel about 15.7 degrees up from neural, and 9.8 degrees down.  Now they can move 18 degrees up and 11.2 degrees down.

Next I had to make some adjustments to the roll servo pushrod.  With everything installed and the newly increased aileron travel, I found that the little servo pushrod scraped the underside of a seat rib hole at full aileron deflection, and the long aileron pushrod ran into the outboard rod end bearing on the servo pushrod at full up elevator.

To solve the first issue, I used a tubing bender to just put a slight bend at the inboard end of the pushrod.  That made enough space above the pushrod to eliminate any interference.

The other change I made was to move the outboard end of the pushrod from the front to the back side of the servo arm.  That got it out of the way of the big pushrod with the stick all the way aft.  I used dished washers again on both ends of the servo pushrod to maximize its range of motion, and now nothing interferes anymore and the pushrod doesn't bind up anywhere!

LH Aileron Pushrod Length (0.5)

0.5 hours

I set the aileron pushrod length, the same way I did the other one.  Pretty easy with two people!

Setting Aileron Pushrod Length (0.5)

0.5 hours

The last part of setting up the aileron is to set the length of the short pushrod.  To do this, you set the bell crank at a certain angle (25°), and then put a straight edge on the top surface of the aileron and measure the distance from the straight edge to the top of the wing at the aft edge of the forward skin (74mm is what you want).

I've heard that you can do this by yourself with the wing skin on, but I think it would be pretty tricky.  I did it with the lower skin off and my wife helping, so it was easy!  I started by rigging up some precision measuring tools.

Here's a square that measures 74mm:

And this device sets the bell crank at 25°:

After a few adjustments I got it where I wanted it.

I tightened the locknut and put a blob of paint on it so I can make sure it doesn't move later.  For now, this pushrod and the aileron can go back on the shelf until later!

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!

Control Pushrods, Part 2 (1.5)

1.5 hours

Continuing with the pushrods.  The flap and short aileron pushrods just had to be assembled from hardware; the long aileron pushrods had to be built from tube stock.

I cut the tubing to length and drilled/riveted the machined fittings to each end.

Then I just screwed in the rod end bearings.  The drawing calls for an initial overall length, which I set, and then I tightened the lock nuts.

All three pairs done!

 

Control Pushrods (0.5)

0.5 hours

I got started on the aileron pushrods.  Most of this time was spent digging through all my parts to find the hardware!

The first step was pressing these bushings into the rod end bearings to bring the ID to 3/16".  I just used my bench vise and they went in pretty easily.

 

Ailerons Part 7 (1)

1 hour

I got my super skinny PRG410 rivet puller from ebay, so I was able to go back and get the last few rivets on the ailerons.  This thing can get in tight corners, it's awesome!  Sonex should add it to their list of recommended tools in my opinion.

The rivets next to the drive rib are a real tight fit, but this PRG410 thing had no problem reaching them.

The counterbalance rivets are pretty tight as well, but not too bad.

 

All flaps and ailerons done!

Back to the wall of parts they go, until later.

Ailerons Part 6 (1.5)

1.5 hours

I got the LH aileron up to the point that the RH one is at.  Once I get my new skinny rivet puller in the mail I should be able to wrap these guys up!

I also added a few more brackets to my wall of parts to store them for now.

Next up is flaps attempt #2!

Ailerons Part 5 (4.5)

4.5 hours

Today I got the LH aileron almost caught up to where the RH one is.

I got smart and used my piano hinge drilling template yardstick to drill most of the holes in the skin.  Since the holes are located at 1" or 2" intervals, all I had to do was measure and locate one hole and then I could easily drill the rest through the template.

After that it was the same process as the other side.

Ailerons Part 4 (4)

4 hours

The RH aileron is just about done!

I picked up a 12" long 1/8" drill bit at Ace Hardware which allowed me to drill the holes on either side of the counterbalance.  I think next time I place an order from Aircraft Spruce I'll get a few long #40 and #30 bits for the future.

 To get the holes between the two counterbalnce plates I had to remove the lead block.  I'll leave it out until the rivets are pulled.

Fitting the tip rip took a bit of messing around but I eventually got it looking pretty decent.  It helped to grab the rib from the inside through the big slot where the counterbalce goes through, until I drilled into my own finger!  More blood offerings to my workbench surface.

Once all the holes were drilled I took it back apart for deburring.  I used a soldering iron and a straight edge to remove the plastic coating from the skin along each roll of holes.

Then I just had to reassemble and rivet the whole thing...

For the few rivets around the drive rib and counterbalance weight, I found a super thin rivet puller that other builders have used, called a PRG 410:

http://sonexbuilders.net/viewtopic.php?f=34&t=2345

I picked one up on ebay for $16 shipped.  Once I get that thing I'll go back and pull these last few rivets.