This afternoon I went back to work on the left elevator. I had to fix up the trim tab cutout tabs by cutting them out and replacing them with a mini-rib. Using my die grinder with a cutting disc, I carefully cut out both tabs.
I then used my back riveting plate, blocks of wood and a hammer and beat the edges as flat as I could to remove the bend radius from the tabs.
I then set my angle marker so that it was square to the spar when laid against the trailing edge. I marked a line as close as I could whilst still ensuring all creases and damaged skin areas would be removed.
Using my micro-files, I removed all damaged areas up to the marked line. I had to remove a touch past the existing forward radius so I used my round micro-file to make a new radius at the required location. Once I had filed both sides back I scuffed the area. Damon reckoned it didn’t look too bad.
I then marked a centreline for the future rivets that will hold the mini-rib in place. I made this in line with the rivet hole for the spar that is slightly forward of this area. I also made rivet spacing the same as that used for the stiffeners (1.5″) so that it would look the same.
Using my #40 bit I drilled out the holes both sides using a wooden wedge in the middle to avoid drilling the skin on the other side.
I then got the bending block wedge that I used for the elevator and marked out the centreline of the wedge angle.
I then set the angle marker up to be half the wedge angle and marked out this angle on some of my alclad stock. I originally used 0.032″ but I later found this to be too hard to bend properly.
I ended up using 0.025″ which appears to be the same thickness as the stiffeners. Here is my second attempt all marked up.
Using my band saw, I cut out as much as I could from my strip of alclad and got it to a manageable size. I then used some blocks of wood and bent along the angled lines to make a tapered mini-rib. This was a lot trickier than I was expecting. I used blocks of wood, hammers, my rivet gun and eventually my vice and some F-clamps in order to get this thing shaped the way I wanted it. The large amount of respect I have for scratch builders only increased after my efforts in making this small piece. Under all these blocks of wood and clamps is my mini-rib … somewhere.
After much head scratching, cursing and advice from the father-in-law, we eventually managed to make something that looked pretty good I reckon.
Using my Scotchbrite wheel and micro-files, I broke the edges then used some masking tape to hole the mini rib into position to test for fit.
I then used a Sharpie to mark the holes on the mini-rib. I drilled the holes on one side, then clecoed the rib into position and match drilled the holes on the other side.
I debarred the holes using TIMMY, then dimpled the mini rib using my angle dimple die. I then sanded the edges and scuffed the mini-rib using some Scotchbrite pads. I’m pretty happy with how it turned out.
Finally, I dimpled the mini-rib holes on the skin using my DRDT2 then shot the mini-rib with some self-etching primer and put it aside to dry. Now … back to the elevator riveting.
I positioned the elevator counterweight and clecoed the elevator together as per the plans.
Using my squeezer, I then riveted all but the last couple of rivets in the trailing edge taper. No real dramas encountered during this part. Here is a photo of the elevator with most of the rivets set. I just need to do the rivets in the taper, the mini-rib and the trim tab spar.
Build time 5 hours.