Yay, rudder!

Kudos to Van’s for timing.  The day after I finished the vertical stab, a package showed up at my front door containing the replacement parts for the rudder.  I celebrated by waiting an additional another day before getting back to work.

This story actually starts on Thursday night, when I had my shortest night of work on the plane ever, at maybe ten minutes.  The first order of business was to redo the R-703/-713 alignment.  I was enthused right off the bat, because the new rib and counterweight skin seemed to not be as misaligned as the first set.  I got out my shiny new Avery fluting pliers and put a gentle flute in the forward flange of R-703.  I checked it against the counterweight skin…not quite.  I applied the pliers again with a bit more force, then checked…still not quite there.  One more time with the pliers, good amount of force this time…hmm, that “flute” looks very angular.  Oh great, I squeezed too hard and cracked the flange.

Given the difficulty I’d now had with two of these things, along with the potential self-loathing I’d feel if I ordered yet another tip rib, I decided to try something different.  My plan was to cut a relief in the middle of that flange, between the two rivet holes.  This would take care of two problems: first, it would completely excise that material I’d cracked, and it would also make it a lot easier to align the holes with the counterweight skin.  It didn’t seem to me like this would compromise strength, but I figured it was prudent to solicit second opinions.  So I asked the great community at VAF what they thought of my idea.  No objections, and one guy had the good idea to add a doubler if I was worried about strength; I decided the doubler was an excellent idea.

Back out in the garage today, I put my plan into action.  I knew that the base of my relief cut needed to be radiused properly to avoid stress concentration, so I decided to start my work there.  I marked out a decent centerline, centerpunched a hole, and drilled it to 3/16″.  Then I marked my cut lines, and the bandsaw made quick work of those.  A cutting bit on my Dremel cleaned up the transition between the bandsaw cuts and the drilled hole, and I finished by dressing the cut edges.  Next I clecoed the counterweight skin in place before rough-cutting a strip of .032 alclad for the doubler.  Clamped that in place (making sure the strip followed the curve of the flange), drilled through the two holes, cleaned up the doubler, and everything was good to go again.

After match-drilling the new rib to the rudder skin, the only thing left was to drill the R-717 attach strips I fabricated a while back.  These strips sit inside the root rib, and they’re drilled by clamping them into place and using the skin and rib as a drill guide.  Slight problem here is that the rib and skin obviously need to be aligned properly for this to work right, but trying to align three sheets and clamp them together isn’t exactly easy.  My “solution” (if you want to give it that much credit) was to cleco the skin to the rib on one side for general alignment, then clamp the attach strip to the other side for drilling.  Worked like a charm.

After that, the rudder came apart and there was deburring-aplenty to be done.  One decent-sized pile of metal shavings later, I was thinking of calling it a night, but decided to get the skeleton pieces dimpled.  This way, on my next work day, I can move right into prepping and priming.  Dimpling went great until I got to the narrow ends of the tip and root rib.  I knew ahead of time that these were tight spaces that would need special tools, so the last time I ordered from Cleaveland, I made sure to order their pop-rivet dimple die sets.  At the time I clapped myself on the back for planning ahead.  Tonight, I discovered that there wasn’t even enough room to get the mandrel for that dimple die set in there.  ARGH!  After some head-scratching, I came up with a solution: I cut down one of the mandrels, only using it to position the small dimple dies in the rivet hole.  Then I was able to get my Main Squeeze with the thin yoke around them, and viola!  Nice little dimples!

I have plans tomorrow afternoon, but I’m hoping maybe I can get out before that and get these pieces prepped and primed tomorrow.  I also still need to dimple and otherwise prep the rudder skin, but I can easily do that between cots of primer.  Assuming I can get things primed tomorrow, I don’t think it’s out of line at all to think I can have the rudder done this weekend. (I should know better by now than to count my pre-hatching chickens like this, but I just can’t help it…)

Here’s that pesky tip rib after I made my relief cut: (edges still haven’t been finished at this point)

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And here it is with the counterweight skin and fabbed doubler clecoed in place:

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And here’s a small pile of parts waiting to be deburred:

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