Aileron control rods

October 28, 2011 – Now that the flaps are built, I’ve turned my attention to the aileron control rods, since the ailerons need to be in place and rigged before I can drill the wing half of the flap hinges.

I started with the rods that connect the aileron bellcrank to the aileron. These tubes are 1/2″ OD steel tubes, powder-coated gray. I cut them to the length called for in the plans.

The tubes get 2 staggered rivets for the threaded fittings on the ends. I didn’t do these like I probably should have, but it worked fine. I used the tape method to locate and drill the rivet holes.

 

 

 

Since the tube diameter is 1/2″, that makes the circumference 1.571″. I laid out and cut a piece of tape to 1.571″.

I then divided the circumference by 4 to get the distance between the holes, and marked that on the tape. What I wish I had done was to be more alert to the drawings and get the dimensions for each rivet from the ends of the rods. I just kind of eyeballed it, trying to get good edge distance for the threaded fittings. Then I wrapped the tape around the ends of the rods.

I piloted the holes with a #40, then took them up to #30 for the rivets. I took everything apart and deburred all the holes, then I primed the threaded fitting mating surfaces.

I set these rods aside until the other ones were drilled.

The larger control rods connect the stick in the cockpit to the aileron bellcrank. These tubes are 1.125″OD aluminum. I cut them to length per the plans, then I set up to drill the holes at the ends using the tape method again. The circumference of the tube is 3.53″ There are 6 rivets on each end, so they would be .58″ apart and 1/4″ from the ends of the tubes. I piloted the holes with a #40 bit, then pressed in the end fittings, picked up the pilot holes, and stepped them up to #30.

These machined aluminum fittings fit very tightly into the aluminum tubing. I had to figure out how to remove them to deburr. So I found a bolt that fit the threaded portion, held the rod on the floor, and used a mallet and a block of wood to hit the head of the bolt to remove the fittings.

I cleaned the insides of the tubes as well as I could, and instead of priming them, I just used corrosion-preventive compound in all four tubes. I sprayed it in until it ran out the other end, all while turning the tubes. Then I let them drain and dry for 2 days.

I primed and painted the big tubes to match the powder-coating on the little ones.

After the CPC was dry, I installed the threaded fittings in the little tubes going to the ailerons. The riveting went OK.

I installed the end fittings in one of the larger tubes using blind rivets. It came out nice.

While all this was going on, I started mounting the ailerons on the wings. I’m ending up doing one wing at a time for now.

Each hinge has a stack-up of spacers and washers. The dimensions and quantities of washers are called out in the plans, but they do leave some room for adjustment. I’m cutting the spacers from a length of aluminum tubing that comes with the kit. I’m just marking the length, and cutting with a small tubing cutter.

Here’s the installation for the left aileron inboard hinge:

And the outboard hinge:

I installed the small control rod:

Here’s the bellcrank with the rigging jig in place:

I then fed the main control rod through the wing and put it in place:

As it sits right now, it looks like the aileron is sitting a little high, but that adjustment comes next.

 

Time: 5:00

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