Pulley bracket, Fabric-backing plates, Joggle

Several small updates:

The pulley bracket for the left aileron had been previously welded but needed painting, so we prep'd and painted it with an epoxy-based gray primer, then sprayed with a gray top coat.  The finished part is shown in the image below.   Two additional fabric-backing plates were created for the left wing (also shown in the picture).

Fabric backing plates and pulley bracket

Lastly, in order to get the cable to line up properly between the pulley and the aileron bellcrank, we put a "joggle" in the aileron bellcrank.  We got this idea based on suggestions from posters in the Wings Forum.  To bend the part, we first covered it in tape to protect the finish, then used vice grips to hold the base while bending the other section with a set of locking sheet-metal pliers.   Total deviation is approximately 4 to 5 mm.  The joggle can be seen in the image below.      Hours: 2.0

Aileron bellcrank with joggle

Left flap pulley bracket attached

Finally,  after all the time spent building a new bracket and fixing the alignment, our newly welded and painted left flap pulley bracket was epoxied and riveted in place.  Smoothed the excess adhesive after it set-up about 30 minutes, and we avoided having too much excess adhesive this time by lightening up a bit on the amount applied.  Hours: 1.0

New flap pulley bracket in its happy new home

Flap and Aileron Pulley Work

Once we were happy with the flap pulley bracket it was time to put some primer and paint on it for corrosion protection.  We bought some 2 part epoxy primer and Mike sprayed two coats on the bracket.  That was followed by two coats of a gloss topcoat paint to match the rest of the airplane parts.  Once it is fully dry we will do a final install.

We moved onto the bottom aileron pulley bracket.  Again, we were not happy with the alignment of the pulley bracket, so we built another.  With the flap pulley under our belts, we were able to make the new bracket much quicker.  While Ed did the TIG welding on the new bracket, Mike made four fabric plates that will be used around the two bottom pulleys on each wing.  One of the fabric plates is ready to be placed.  The other three are in a template form and once a custom notch is done they would be ready for placement as well.  Hours: 5

One completed Fabric Plate, One partially completed Fabric Plate
and the bottom Aileron Pulley Bracket drilled and Cleco'd.

Left flap pulley fix

Many hours were spent fixing the alignment problem with the left flap pulley.  We originally planned on building all new parts, and even carefully bent some steel in order to have the new base match the radius of the spar (see picture below).  However, after more thought on the matter, we decided to salvage the base from the original pulley bracket because it had already been drilled (as it was previously riveted) to the spar.  So by reusing that piece of the bracket, we didn't have to worry about precisely lining up 4 new holes with the ones already in the spar.

Michael is bending some steel around a pipe to set the radius

We created two new bracket arms (twice, because we cut the first set just a little too short).  Holes were drilled and reamed for the pulley bolt, and the parts were deburred.  Using a straight wire that has a 90 degree bend, we determined the correct alignment by lining up the pulley with the holes in the rib and the flap horn.

Ed cutting pulley bracket arms using a cut-off wheel

For the purposes of welding, a couple spacers were made out of steel to maintain the spacing between the arms, and then the pulley was replaced with the spacers.  We clamped the arm assembly to the base, and I then welded the bracket arms to the base with TIG, using ER80SD2 welding rod.

After everything cooled off, we tested alignment by putting it back on the spar (See image below).  It's a thing of beauty.  The bent rod shows that we now have good alignment from the hole in the rib, to the pulley, and then up to the flap horn.  Hours: 10

Bent rod showing good alignment of the newly welded pulley bracket

Flap Pulley Issue

Well, we thought we were done with the left flap pulley, but there's a problem.  We noticed that once fastened in place, the pulley was slightly angled up and to the left.  I think it was probably originally welded like this from the factory, because the back side of the pulley bracket is shaped to fit the spar which fixes it's angle once it is lined up with the flap horn.  We hoped this wouldn't be an issue, but to know for sure, we wanted to test the pulleys with cable to ensure there was no problem.

To do a test run with cable, we needed to drill holes in rib webs #1 and #2, which required using the templates supplied in the manual.  There-in lies another problem!  Turns out the templates printed out from the manual were "squished" a bit (for lack of better word) and did not have the right aspect ratio.  Some of the template holes were actually oval instead of round.  Don't know about you, but it's pretty hard to drill an oval hole.  Some of the templates were worse than others, and when cut out, the original templates were not even the same shape.  After some investigation, Michael found that the original images had been resized when inserted into the manual (a Word document).  By removing the images from the Word document and copying them into another application, he could recover the originals with the correct aspect ratio.  This was a great find and the new templates are all the same shape, and all the drill guide holes were round.

Drilling out the rivets in the flap pulley bracket

After drilling the cable holes in ribs #1 and #2, we ran a cable through the holes, around the flap pulley, and to the flap horn.  We then tested the flap motion by pulling and releasing the cable.  It worked, but the cable was rubbing the side of the pulley pretty severely, and you could even feel the extra friction when pulling by hand.  Not good, and we both agreed we needed to remove the pulley bracket and fix it.  Bad news is that it was already riveted and epoxied in place.  After some research, we found that parts like this can be removed by softening the epoxy with a heat gun.  We drill out the rivets, and then applied heat with a heat gun (being careful to shield the wood rib and the fuel tank to prevent these from heating up).  This worked great, and the flap pulley bracket popped off.   Next steps will be to fix the bracket (or maybe even build a new one), in a way that allows the cable to have a smooth motion to the flap horn.  This will be more difficult since we now have holes already drilled in the spar, but nobody said building airplanes was easy.  Hours: 3

Correct alignment shown with a bent solid wire