Monthly Archives: February 2015

Ailerons 16 (6.0 hrs)

This entry was posted in Ailerons Wings Wings - Structure on February 28, 2015 by Peter

Today I set about drilling the remainder of the aileron push rods. First I measured the circumference of the tube using a post-it note. I then divided that number by 6 to get the appropriate spacing and made marks for each rivet hole location. (IGNORE the math, as measured incorrectly on the first pass, and forgot to take a picture of the correct post-it note. The principle is the same though.)

Then I used another bit of post it note to hold the rod ends in place for the first drill before using a cleco. I decided to prime after drilling everything instead of before.

I set up a makeshift jig to ensure the rod was centered. I should have done this for the shorter rods too.

I had to slightly adjust the position of the jig base so that there was room for the clecos.

Next I setup for priming by scuffing the surfaces with scotch bright and then cleaning with acetone. I used the rudder hinge pin to push the acetone cheese cloth through the pushrods. I then taped the ends and poured AKZO into each pipe and shook. I repeated this process a couple times and then primed the outsides with the HVLP gun.

Ailerons 15 (1.5 hrs)

This entry was posted in Ailerons Wings Wings - Structure on February 27, 2015 by Peter

Tonight I reamed the bell crank bushings. I ordered a 0.2490 reaming bit off of Amazon. The bolts are slightly undersized. There is no need to go the full 0.25 inches. Further if you ream with a regular bit you could scar the inside of the bushing. Remember the bell crank rotates about the bushing. The bushing does not rotate around the bolt. Since this will connect to the control stick, I’d like to keep tolerances as tight as possible so that the controls have minimal slop over the life of the aircraft.

To ream the bushing, I drilled a hole in a 2/4 with the drill press the same size as the bushing outer diameter. I then put the bushing in the hole, and reamed the center, using the 2×4 as a jig.

Next I drilled the short aileron push rods. Be careful these can be a bit tricky.

Ailerons 14 (1.0 hr)

This entry was posted in Ailerons Wings on February 21, 2015 by Peter

Now that the flaps and ailerons are complete its time for connecting the bell crank and pushrods. This should be a relatively quick project. Unfortunately, today’s weather cut my shop time short.

I started out by measuring the two push rods. Be careful, there are separate measurements for the RV-7 and the RV-8.

I wrapped a yellow post it note around each pushrod to get a perfectly circular measurement. As always, I marked the bad side with “X”s so that I know which side of the line to cut. I will clean up with a file before priming. Speaking of priming, I haven’t quite decided on which primer I will use. I sometimes use the basic self-etching primer in a can for small parts, but these parts are important enough that I may break out the AKZO. We’ll see which I pick.

Before I cut the rods, I wanted to make sure I understood how everything connected. I also needed to do some organizing. Turns out there are several types of bolts that I have never separated into different bins. I took care of that quickly. I also cleaned out some of the holes on the powder coated bell crank. Van’s does not do a good job of deburring these parts prior to powder coating. Steel isn’t nearly as susceptible to stress cracks as aluminum, but still its slightly annoying. I debated cleaning it up further, which would require additional primer. In the end I decided if its good enough for Van’s, its good enough for me.

Then I cut the push rods to size.

There is a lot more snow than it looks like in this picture. The wind is pushing it into drifts. By this time we had close to a foot, and it was still coming down. I figured I shouldn’t push my luck and decided to head home.