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Archive for January, 2011

Completed Riveting Aileron Stiffeners – 1.5 hrs

January 31, 2011 Leave a comment

Monday Jan 31, 2011

Winter is flying by, no pun intended. I glad about that because I don’t really like working in a cold garage. But this is California so why am I complaining?

Tonight I finished back riveting all the stiffeners onto the aileron skins. These rivet look great. Nice and flush to the surface. That took about an hour to complete.

Aileron stiffeners finished

I also started riveting the leading edge section to the right wing. I was solo so I could only do the easy ones; the ones on the most outboard rib that I could get the squeezer on with a 3-inch yoke though the lightening hole.

Outboard rib rivets for the leading edge

Categories: Ailerons, Leading Edges, Wings

Wing and Aileron Progress – 5 hrs

January 30, 2011 Leave a comment

Sunday Jan 30, 2011

This morning I got into the garage early. The first order of business was to start squeezing rivets along the aft spar of the left wing.I could not do them all because some of the skin to rib rivets are not installed yet but I could do the entire inboard skin.

Next I de-vinyled the left aileron skin, deburred edges, and scotch-brite scrubbed the interior surfaces along the rivet lines. Here is a progress shot.

De-vinyling the left aileron skin

After church I dimpled the aileron skins, cleaned the surfaces with MEK, and washed the stiffeners with Simple Green.

Dimpling the aileron skins

I shot a light coat of Stewart Systems primer on the stiffeners and along the rivet lines of the skins on the interior. Cutting the blue vinyl along the rivet lines provides a simple mask to keep primer weight to a minimum.

Skins and stiffeners primed

Then I back riveted one set of eight stiffeners on the left aileron skin. Twenty four more to go.

Backriveting stiffeners

I also put in a few more rivets along the aft spar of the outboard top skin on the left wing between a couple of the ribs we riveted yesterday. I am out of -4.5 rivets and running low on -4 also so I ordered more from Vans today.

More wing skin rivets

Categories: Ailerons, Skins, Wings

Riveting Left Upper Wing Skins – 4.5 hrs

January 29, 2011 Leave a comment

Saturday Jan 29, 2011

This morning I deburred the edges of the right aileron skin and removed the vinyl along the rivet lines inside and out. I also scrubbed the inside surfaces with scotch-brite to prepare for priming. In addition, I scrubbed the stiffeners with scotch-brite and dimpled them; all 32 stiffeners.

Preping aileron skins and stiffeners

This afternoon my friend Scott came over to help me work on top skin riveting. This was his first time riveting so I gave him a short lesson. After four or five rivets he had it down and he did a great job. He used the swivel flat set and I bucked the shop heads. We switched from back riveting these because I felt like we had more control of the quality of the shop head with this technique. The long reach double offset back rivet tool is hard to control. That’s Scott on the left

Scott helps with wing skin riveting

Together we completed all the rib rivets on the inboard panel and three ribs of the outboard panel. There are still three more ribs to do on the outboard panel and the overlap between the inboard and outboard panels. We skipped all the perimeter rivets that I can squeeze solo.

While the drawing calls for AN426AD-3.5 for most of the skin to rib rivets I found that AN426AD3-4 rivets gave a better shop head. The protrusion of the -3.5 is a little shy of 1.5 D so the shop head is kinda thin when set to spec diameter of 0.140. The -4 is a little longer than 1.5 D but I had only one rivet bend over when setting out of a couple hundred. I also found that -4.5 worked better along the top row through the spar than the -4 called out on the drawing. I wonder if other builders have found this also?

Here is what the left wing looks like at this point. Still some clecos for the skins but making progress.

Upper skin riveting about 60% done

Categories: Ailerons, Skins, Wings

Fuselage Ordered

January 28, 2011 Leave a comment

Friday Jan, 28 2011

I ordered the fuselage kit today. Slow build, tricycle gear, tip up canopy, and electric aileron trim. I also ordered steps for both the pilot and passenger sides of the fuselage. I would have waited another month or two to order the fuselage but the prices will go up on Feb 1 so I moved out now.

Categories: Fuselage

Backtracking for 7 Missing Rivets – 1.5 hrs

January 27, 2011 Leave a comment

Thursday, Jan 27, 2011

I hate to backtrack but sometimes you just have to. I had already started riveting the inboard top skin to the left wing skeleton when I noticed an empty rivet hole that shouldn’t be there. It was at the very top of one of the wing ribs at the main spar but it was under the fuel tank skin and you have to look from the inside of the skeleton to see it was missing. It is one of those mystery rivets that I can’t find on any of the drawings and it’s not mentioned in the plans. There are seven of these rivets on each side of the wings. I had identified them on the right wing and installed the rivets but I had forgotten these.

So tonight I removed the left fuel tank and install the rivets that should have been there. Fortunately I have an electric screwdriver to help take out all those flat head screws. The picture below shows one of the mystery rivets. The red arrow points to one of the rivets after I installed it. Well at least I’m back on track now.

Arrow highlights the missing rivet

Categories: Fuel Tanks, Skins, Wings

Drilling Aileron Stiffeners and Skins – 1 hr

January 24, 2011 Leave a comment

Monday Jan 24, 2010

Tonight I finished match drilling all the aileron stiffeners to the skins. Then I marked each one to identify its position so I can put it back there after priming.

Aileron stiffeners drilled to skins

Categories: Ailerons, Wings

Right Leading Edge, Skin Riveting, Started Ailerons – 5 hrs

January 23, 2011 Leave a comment

Sunday Jan 23, 2010

Today I completed the last 42 rivets on the right leading edge section. These were difficult to reach solo so I got Denise’s help and we knocked them out in less than an hour.

Right Leading Edge completed!

Then we started working on riveting the top inboard skin on the left wing. The instructions recommend using a long double offset back rivet set and a large bucking bar to set these. So Denise held a 5 lb bucking bar on the top surface of the wing and I drove the back rivet tool from the inside of the skeleton. I was surprised that I had to turn up the pressure to get good shop heads. I usually drive 3/32 rivets at about 35 psi but I had to crank up the regulator to about 60 psi to get a well formed shop head in a reasonable number of strikes. I’m not sure why but I have read that other builders have also encountered this. The first three rivets were not great so I drilled them out and reshot them.

The instructions also say to start in the middle of the skin section and work outward to keep the skin tight. So we did the two middle vertical rows first. Denise needed to leave so we stopped there for today.

Started top skin riveting on left wing

Since I was solo again I started preparing the 32 stiffeners for the left and right ailerons. These are pretty much the same as the stiffeners used on the rudder and elevators so I knew the routine. Cut them out of stock along the pre-punched notches. Taper the web using snips, use the belt sander to achieve the final shape, and deburr edges with the scotch-brite wheel. Here are the 32 stiffeners cut to final size and shape.

Aileron stiffeners

Then I started match drilling the stiffeners to the aileron skins. I only had time to do one side of one skin (1/4th of the total) so I will pick up here next time unless I have help in which case I will work on the left wing skin riveting.

Match drilling aileron stiffeners to skin

Categories: Ailerons, Leading Edges, Wings

Riveting the Right Leading Edge – 3 hrs

January 22, 2011 Leave a comment

Saturday Jan 22, 2010

Today I riveted most of the right leading edge structure together. Did not have a helper but I was able to buck all but three or four rivets along each rib solo. I’ll need a helper to shoot the rest.

Right Leading Edge Riveted (mostly)

I also reinstalled the fittings on the two small aileron pushrods. This was kind of a pain because the rivets are long a tricky to shoot. My squeezer won’t work on them because the rivets are so long. When I bucked them with the straight set the rivets want to bend over so you have to be really careful. I had to drill out one rivet and shoot it again. After successfully bucking these I cleaned the surface with a little MEK and brushed on a light coating of EkoPrime because there was some bare metal showing.

Reinstalled aileron fittings

I stopped by Aircraft Spruce today and picked up a few things; another quart of EkoPrime, some Aeroshell 7 grease for the aileron bellcranks, a tube of EZ Turn (aka fuel lube) for the fuel drain fittings, and some AN316-6 jam nuts because my kit was one short.

Categories: Leading Edges, Pushrods, Wings

Redo on the Aileron Pushrods – 1 hr

January 21, 2011 Leave a comment

Friday Jan 21, 2011

Well I’ve been out of town for a few days so there has been a short lull in the building progress. But I had some excitement while gone. I was at Vandenberg Air Force Base helping prepare the Glory satellite for launch on Feb 23 if all goes as planned. I had a role in building the aerosol polarimeter on the satellite and we are performing final inspections before launch. I happened to be there when a large rocket was launched on base and had a chance to see it lift off from about 5 miles away. Very cool!

While I was gone it occurred to me that there was something I forgot to do when assembling the small aileron pushrods. I forgot to prime the inside of the tubes. Dang! So I tonight I removed the two rivets on one end of each pushrod and coated the inside of the tube with primer. I thinned the Stewart Systems primer with distilled water to make it easier to get 100% coverage on the inside. I’ll reassembly the tubes later this weekend when the primer is good and dry.

Fitting removed to prime the interior of the tubes

I also had one rivet on the left leading edge that was bugging me. The rivet had leaned over a little and was probably OK but I decided to drill it out and replace it. I couldn’t live with it. Instead of bucking a new rivet I decided to use a LP4-3 pop rivet instead. Many builders use these for all the leading edge to spar rivets so the strength of the LP4-3 rivet is no issue. The rivet in question is the one on the far right in this picture. No new progress tonight but I feel better now.

Replaced a leaning rivet with a pop rivet

Categories: Leading Edges, Pushrods, Wings

Primed and Dimpled Left Wing Top Skins – 4 hrs

January 16, 2011 Leave a comment

Weather was great again today so it was a good time to prime the left wing top skins. For some reason I did this in a odd order. First I dimpled the inboard section as you can see below. Normally I would have done the scotch-brite job on the surfaces to be primed first because if you do it after it is easy to enlarge the dimple holes if you get a little too aggressive with the scotch-brite.

Dimpling the left inboard top skin

So I ran the scotch-brite carefully over the interior surfaces along the rib lines and the entire area where the wing walk doubler overlaps and then set up the paint gun to prime the surfaces. This time I just used a few pieces of cardboard to mask off the surface I did not want primed. Then I realized I did not dimple the outboard section so after the primer cured in the sun a while I dimpled it with a little help from my daughter Jessica.

Getting some help dimpling the outboard top skin

Then I cleco’d the skins to the wing skeleton to set up to shoot rivets.

But just for fun I made the two smaller aileron pushrods. This means cutting the tubing to length, pressing in the end fittings, cross drilling for rivets, and bucking two rivets on each end. This didn’t take too long.

Aileron control pushrods

Categories: Pushrods, Skins, Wings