Two Forward, One Back

Here is a photo of the parts, at this point, for the second upper aileron pulley:

You may be wondering why it appears that there are two top strap blanks, one longer than the other.

The answer is that I did not have my head fully in the game.  The shorter one was cut out first.  It will end up in the trash.  The top strap is supposed to measure 2.70" between the hole (not yet drilled) centers.  Not paying full attention, I fabricated the first attempt 2.70" long overall.

The holes will be drilled in the longer, and correct length, top strap after bending. It is advisable to drill holes after bending to be sure the holes end up in the correct location.  Bending can introduce errors in the hole locations if the holes are drilled before bending.

Not only is this sound advice to be found on the EAA website, I can personally attest to its wisdom. How do I learn these things?

One other interesting point on these parts. It took me two months to fabricate the first top aileron pulley bracket.  If I hadn't made the measurement mistake, the second one would have taken a little over an hour. As it stands, the assembly is between 1/2 and 3/4's of an hour from completion.

More Pulleys

So I started fabricating the top/rear aileron pulley brackets.  At first my attempts were centered around the pulley choice from the previous post.  It didn't work very well.

Then I remembered a comment by internet contact, Mike Finney (who just happened to take Reserve Grand Champion, Plans Built at Oshkosh last year), about roller bearing pulleys.

I went shopping again and found the roller bearing pulleys.  Here is one alongside the aluminum pulley with the bushing.

As you can see, the roller bearing pulley is a phenolic pulley, but with a sealed roller bearing.  This is a very nice pulley and really makes sense as the center component of the aileron pulley assembly.

Here are the component parts of the pulley assembly.

The hardware-store nut and bolt will be replaced with proper AN hardware when my back-ordered shipment arrives.  The bracket and the top strap are fabricated from .050" 4130 steel.

And here is the completed (well, almost) assembly.

The basic concept and design comes from another internet contact, Marty Feehan.  He was kind enough to send me photos and drawings. You can see how this assembly mounts in the previous post "A Brief Hiatus".

The bracket and top strap need final cleanup, priming and painting.  I have one more of these to build.

Pulleys

Which pulley would you use?

The pulley on the right is manufactured exactly according to Piper specifications and is certified for use on Piper aircraft from the J-3 Cub to the PA-22-135 Tri-Pacer.  Is is manufactured from phenolic and the grip (the unthreaded part of the bolt) on the bolt that secures the pulley in the bracket serves as the shaft on which the pulley is mounted.

The pulley on the left is an after-market product (Javron, Inc.).  It is CNC machined to the correct dimensions from aircraft grade aluminum, anodized, and fitted with a bushing as the main bearing surface. It is also certified for use in Piper airplanes from the J-3 Cub to the Tri-Pacer. 

Yeah. Me too.  There are plenty of Piper aircraft flying around today that are fitted with the phenolic pulley, but the aluminum pulley, with the bushing, gives me a much higher level of confidence.

These pulleys are aft aileron pulleys.  More details as I get the brackets fabricated.

Aileron Hinges

The Aileron hinges are finished!  What with learning new skills, relearning old skills and acquiring some new tools, this project has taken since October.

If you are in a hurry to fly, scratch building an airplane is not the way to do it.  I love the process, and I am having a lot of fun, but I have a flying airplane up in the hangar. 

This photo came out a little dark, but that's OK.  It just documents the existence of six aileron hinges waiting for their coat of yellow paint.