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Installed Rudder Fairing, etc. – 9 hrs

April 20, 2014 Leave a comment

Sunday April 20, 2014

Easter weekend, so happy resurrection day! I had the chance to fly an RV-7 (N223J) on Saturday with Jake Lewis, a neighbor in Mission Viejo and resident of a hangar at KAJO. We flew out to San Clemente and up the coastline to Huntington Beach. He let me pilot from the right seat most of the time. It was a blast. So much different than the C172 and I am anxious to put the spam can days behind me.

Back at home after lunch I completed the final installation of the lower fairing on the rudder. I had drilled pilot holes but I needed to install nutplates and countersink the fiberglass for Tinnerman washers. Here is a view of the nutplates installed along the attachment strip.

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And here is a view with the fairing installed with the washers. I guess I could have spaced the screws out a little more and used fewer. This thing is on solid.

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I also made and installed a tab for the local electrical grounding of the strobe light. I needed to ground the cable shielding on both ends to minimize EMI concerns but there was no convenient place to screw down the ground lug. So I made a tab, installed a nutplate on it, and riveted it to the bottom rib of the rudder.

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On Sunday evening after getting home from my daughters place I installed the nutplates on the horizontal stabilizer for the empennage fairing. Here is a view of the fairing test fit.

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The list of things to do before moving to the airport is getting shorter and shorter.

Installing Tail Light Adapter – 2 hrs

July 31, 2010 Leave a comment

Saturday July 31, 2010

Denise spent the whole day cleaning out the garage yesterday. I didn’t ask her to, she just decided that I could work more efficiently if the place was more organized and uncluttered.

She is right. It’s a pleasure to be out here now and I feel like I am ready to start the wings.

In the mean time I am working on dismantling one of may patio covers to replace some rotting beams. That is no fun. I can’t stay away from the airplane factory completely so I scotchbrited the tail light adapter and cleaned it. Then I sprayed on a good coat of primer and let it dry in the sun.

Then I used CS4-4 pop rivets to mount it to the rudder bottom fairing. It was a little tricky because of the counterbores in the adapter. The nose of the rivet puller won’t go down in there so I stacked up six small washers on the rivet head when I pulled it. That did the trick and all the rivets were set flush to the bottom of the counterbore. Here it is ready to receive the tail strobe light.

Categories: Rudder

Tail Light Adapter Part 1 – 1 Hr

July 29, 2010 Leave a comment

July 29, 2010

My tail light adapter and tank dimple dies arrived from Cleveland Aircraft Tools today. I’ll need the dimple dies when I get to the fuel tanks but for now I can install the tail light adapter on the rudder bottom fairing. Here is the little $17 aluminum part.

I aligned it to the fairing contour by eye (a little awkward) and match drilled the holes in the fairing. The alignment turned out OK in spite of the fact that the fairing is not perfectly symmetrical.

Then I marked the center hole on the fairing and drilled it out using a 1 inch spade bit from my woodworking supplies. That worked surprising well. Then I smoothed out the edges of the fiberglass with my rotary tool and a sanding drum.

Ready to prime the adapter and install it with CS4-4 rivets.

Categories: Fiberglass Tips, Rudder

Finished Elevator and Rudder Tips – 4 hrs

July 17, 2010 Leave a comment

Saturday July 17, 2010

Big day today. I officially finished the elevator tips, rudder top tip, and vertical stabilizer top tip. The morning started with sanding out the dry micro that I applied last night on the VS tip seam. After shaping and blending it into the skin and the fiberglass there were several low areas where more filler was needed so I mixed another batch and applied that.

It was hot again today so it only took a few hours for it to kick over. Then I sanded it again to get the final clean shape I wanted. Seam gone!

Next I broke out the spray gun and sprayed on a few light coats of UV Smooth Prime, which I had learned about on the forums. It fills pin holes and small defects and sands out really smooth. It also provides UV protection to the fiberglass. I guess that’s important. It drys pretty fast too in light coats so it was only about a half hour before it was ready to sand.

Here is the finished VS tip.

Then I sprayed UV Smooth Prime onto the two elevator tips and the rudder top tip. I’m new to working with fiberglass so I am happy with how well these came out.

Here are the two elevator tips.

Here is the rudder top tip.

And here is how the rudder and VS tips fit together.

Here is a closeup of the gap.

I retrospect I am glad that I have time before my wing kit arrives (week of August 8 according to Vans) to finish the fiberglass on the empennage. Most builders postpone it until after the wings and fuselage are done. But I would rather get this dusty stuff done and out of the way. If the wing kit was already here I am sure I could not resist the temptation to focus on that because there is so much satisfaction in seeing the big pieces come together. But now I know how time consuming the fiberglass work can be if you have a perfectionist approach, which I sorta do. It has take a lot more hours than I ever expected and I learned a lot. Hopefully something I posted here may help someone in addition to documenting my process for the FAA.

Ah, but I get ahead of myself. Next: Filling the seams on the horizontal stabilizer tips and installing the rudder bottom tip.

Finished the Rudder – 3.5 hrs

March 20, 2010 Leave a comment

Last night after work I installed the last few rivets on the top and bottom ribs of the rudder. These are the ones I left out earlier so I would have a little easier access to the trailing edge for bonding. Those rivets in the very narrow end of the ribs are a bear. I was able to buck all of them except the last one on each side of the top rib. There I used the Vans-approved pop rivet. It was so narrow in fact that I could barely get the second pop rivet in because the shank ran into the opposite rivet body. So I ground off half the tip of the rivet shank before putting it in and it seated flush.

This morning I began to roll the leading edge of the rudder. This is another dreaded step because it requires bending the skins into a cylindrical shape using a pipe or broom handle. I followed the instructions in the plans verbatim and it came out fine. I did it in three sections. Here is the top (shortest) section rolled and cleco’d.

You can just see the end of the  broom handle taped to the skin in the second section in preparation for rolling. The first section was misleading. It was so short that rolling was relatively easy. The second section was about four times longer and it was tough getting the skin to roll far enough to achieve the desired shape. My hands were tired afterward. Here is one side of the second section rolled.

Here both sides of the second section are rolled and cleco’d.

Here is a closeup so you can see the rolled shape. It is ideally a perfect cylinder. It’s actually pretty close so I am happy.

Here it is with all three sections rolled and cleco’d. Ready to rivet.

The riveting was straightforward. Match drill, deburr, pop rivet. Here is the completed rudder. I removed the blue film for long term storage.

I couldn’t resist hooking the rudder up to the vertical stabilizer to check the alignment and freedom of motion. It all looked good. Very smooth motion.

The gaps between the rudder and vertical stabilizer look really good. This is a testiment to the quality of the kit since I just built it to the plans and it came out right. Here is an example.

On to the elevators!

Categories: Rudder

Riveting the Rudder Trailing Edge – 1.5 hrs

March 18, 2010 Leave a comment

After the Hysol epoxy cured for 24 hours I removed the clecos and the aluminum angles from the trailing edge of the rudder. The edge looked nice and straight but it was too late on Tuesday night to start riveting so I just cleaned up the excess epoxy and inserted rivets in each hole for back riveting.

Tonight I started back riveting the tricky trailing edge per the instructions. The plans say doing this and getting a straight trailing edge  is one of the most challenging steps in building the entire airplane so there is obvious anxiety. I drove every tenth rivet about half way with the back rivet set on my gun, then went back and drove the rivets half way between the first set, and so on until all the rivets were half set. I checked the trailing edge about every fifth rivet to look for signs of curvature. So far so good.

Then I flipped it over and back riveted the factory heads with my flush set in the same basic sequence. Finally, I flipped it again and finished the shop heads with the back rivet set.

The final result is a nice straight trailing edge. I put the aluminum angle back on the surface just to compare the straightness. There is no more than .025 inch gap at any point between the angle and the trailing edge. I don’t think I could get it any better.

I’m hot and sweaty now. I think I’ll go take a shower.

Categories: Rudder

Bonding the Rudder Trailing Edge – 1 hr

March 15, 2010 Leave a comment

I received the Hysol flexible epoxy today via UPS. When I got home from work everything was set to go. I mixed up about one third of the material and applied a thin layer on the wedge and a bit to the surface of the skins also. I once knew an aerospace bonding expert that told me one of the secrets of getting a good bond was applying it to both surfaces before mating the parts.

Then I put an aluminum angle on each side of the rudder and cleco’d it together with a cleco in every hole. Now its time to let it cure. I hope the clecos don’t get permanently bonded in. I put a little petroleum jelly on the clecos before I installed them as a release agent. I hope that works. I’ll know tomorrow.

I oriented the rudder vertical so gravity doesn’t even have a slight chance to bend it or twist the trailing edge while it cures.

Categories: Rudder

Riveting Skins onto the Rudder – 3 hrs

March 14, 2010 Leave a comment

The Goop had set well when I checked it this morning so I removed all the weights and made sure everything looked good. Here is a view of the stiffeners bonded in place on the right side skin before I closed it up.

The view of the left side skin is essentially identical.

I cleco’d both skins to the skeleton and checked for oil canning on both sides. It is now 98% gone. I can still see a slight amount in one or two places because I only added stiffeners in every other bay but it is way, way better and I am happy that I took what has essentially been an extra week to add the stiffeners. I won’t regret it later.

Then I started riveting the skins on. Most of the main spar rivets could be squeezed but four on one side had to be bucked because the 3 inch yoke wouldn’t quite get there. I installed the bottom attach strips and squeezed all but the four aft-most rivets for those. I could reach three of the Rudder Horn Brace rivets on each side with the longeron yoke but I used a CS4-4 pop rivet on the forward-most rivet in the corner per the plans. Along the top rib I squeezed all but the four aft-most rivets to leave the edge free to apply bonding material for the dreaded trailing edge riveting process. Here it is ready for the trailing edge work.

Here is that Horn Brace pop rivet.

Categories: Rudder

Bonding Rudder Lateral Stiffeners, Second Side – 1.5 hrs

March 14, 2010 Leave a comment

This update is for Saturday, March 13, 2010

I checked the curing progress of the Goop last night after 24 hrs and it had set up pretty well. Probably not full strength yet but maybe 80% there. I decided to leave it alone until Saturday morning to give it more time.

Saturday morning I removed the weights and flipped the rudder over to check on the effectiveness of the lateral ribs as a remedy for the undesirable oil canning effect. After clecoing the skins to the skeleton it was apparent that the lateral ribs have effectively eliminated the oil canning. Hooray!

I prepared the surfaces of the skin on the right side and preped the bonding surfaces of the stiffeners. This time a left the stiffeners flat because I could not detect any significant bow to the skin between longitudinal stiffeners. I applied the Goop as before and set it up to cure. However, this time I set up a small space heater by the rudder to blow warm air onto the assembly to accelerate the curing process a bit. After a half hour I checked it and the skins were warm to the touch, but just a little. I left the heater on a few hours until I had to leave to go to a wedding.

Categories: Rudder

Bonding Rudder Lateral Stiffeners, First Side – 1.5 hrs

March 14, 2010 Leave a comment

This update is actually for Thursday, Mar 11, 2010

While waiting for the Hysol E-90FL to arrive from Amazon I did an experiment with the Goop adhesive. I made a couple of sample ribs from scrap and bonded them together with the Goop. After 24 hrs I was favorably impressed with the strength and durability of the bond. It does remain flexible but tough like rubber and it adheres well to the aluminum. Another advantage is it works well with a thick bondline whereas the Hysol is strongest with a .004 – .008 inch bondline.

So I decided to go ahead and bond on the four lateral stiffeners on the left side. First I put a slight bend in the four stiffeners to make the shape match the slight bow of the skin (approx. .050). Then I re-cleaned all surfaces with MEK and applied a layer of Goop to both surfaces. Then I placed the ribs on the skin and pressed down to squeeze out excess Goop. The adhesive squeezed out around the edges and though the holes in the web of the ribs making little dome heads essentially like rivets. I placed weights on the ribs to keep them in contact with pressure while curing.

Categories: Rudder