Month: July 2019

Just an hour or two tonight, and only managed to get through deburring the rear spar. Scotchbrite pads for the most part, across the drilled holes and in the corners of the harder to reach spots. Edge deburring tool and the Scotchbrite wheel took care of the edges. In the process, I found three holes that I hadn’t drilled in the spar and doubler. Will need to drill and deburr those tomorrow night. Hopefully one more evening and I’ll have everything deburred. Then it will be dumpling and counter sinking, then I’ll prime, and then start riveting it all together.

Spent a couple of hours tonight deburring parts for the Vertical Stabilizer. I started with the ribs and focused first on VS-705 which had been scratched from the press. This took the longest time as I tried to completely remove any trace of the scratches. It came out looking good, as did the other pieces. My main tools were scotchbrite pads, and the scotchbrite wheel on my bench grinder. I also used a small flat file in a couple of hard to reach spots. Hoping to get the spare done tomorrow night, and then the skin, so I can start priming all of these parts. Tonight’s effort seemed very time consuming, but this is due mostly to the scratch removal needed on the ribs, which shouldn’t be a problem with the spas and skin, which don’t (currently) have scratches.

The same piece before deburring:

Tonight I spent 3 hours going through the next few steps, ultimately getting all of the match and finish drilling done on the vertical stabilizer. I started by final-drilling the spar to rib holes, #30 size. There was a call out in the plans to match drill the middle holes in two of the ribs, but I found there to already be holes in the ribs, so it was really a case of finish drilling them.

With that done it was time to fit the skin! It was neat to get the skin on and to see a real airplane part taking shape. I was pleasantly surprised at how well everything fit together. Everything lined up nicely, and I was happy with the fit.

At this point I was contemplating calling it a night and going to bed, but I decided I wanted to get the drilling done and the piece disassembled if possible. The drilling went fairly quick, and within an hour I was done and starting to disassemble the parts.

I found one hole I had neglected to drill, so I drilled it and then finished disassembly. Next step is to deburr all parts.

Reading ahead, the plans suggest priming after deburring, but before counter sinking and dumpling. I’m going to ask my EAA chapter members tomorrow how others went about this. It seems like priming should happen after counter sinking, but perhaps there is a good reason.

Spent a few more hours this evening working through the next few steps. First, I final drilled all the rear spar holes for the doubler and the rudder hinge attachments.

With that done, I spent most of the next couple hours reading, researching, and doing some rib flange radius’s, and fluting the ribs. By radiusing the leading edges of the rib flanges, I hope to avoid the possibility of skin deformities once I start riveting. Hard to know how much to round the edges, but given the thickness of the material, I think I did a good enough job.

Fluting the ribs straightens out the rib “web”, which can come out bent from the press. I watched a few “hints for home builders” videos tonight, including one of fluting, and was happy to see the results once I got started. The ribs straightened right out with just a small set of flutes down each side. Then it was time to cleco the vertical stabilizer frame together.

I wanted to move to the next step and drill the holes where the ribs and spars mate, but it was too late and I was too tired. Quite while ahead, I figured.

Spent about 3 hours today going through the first steps in building the vertical stabilizer. The step by step instructions and the diagrams are excellent, it is very clear and easy to follow. I started by final-drilling the forward spar doubler, trimming the bottom of the spar, trimming the doubler, deburring the doubler and the bottom of the spar. Then dimpling the spar and the doubler plate. I held off on riveting, as I want to prime those parts first. Then I started on the aft spar; final drilling the rudder hinge brackets, and clecoing the doubler and brackets together. But before I could cleco these parts I needed to straighten the doubler which was bowed to the point that each end sat about 1.5 inches off the work bench. It took much trial and error to straighten, but ended up with within the 1/16 tolerance.