|July 9, 2004||HOME|
Since all the work of late has been on the horizontal tail parts and those are about ready to fit to the fuselage, I wanted to get to the vertical stabilizer and rudder. The only difference between anything done on the horizontal surfaces and the vertical is that I'm attaching the VS tip with screws so that I can take it off.
I had some #6 non-struct screws and nutplates that surely would have been adequate, but I decided to go with 8-32 structural flatheads. I first marked the screw positions based on the pre-punch in the VS.
I drilled the first leg of the nutplates through the fiberglass and the .025" alclad backing I had cut, being careful to hold each nutplate in place from the backside with a started screw.
In case you have poor vision and couldn't tell from the above pic, here's a closeup! ;-)
Finally, I moved the nutplates to the inside and riveted through with flush rivets. I know someone is going to tell me that the unsupported rivet heads can work through the fiberglass and cause cracking. Well, remember, there's no tension on the rivets and the rivet heads as well as the fiberglass will be held firmly against the inner wall of the VS tip. The rivets only hold the nutplates in place while the screws are being tightened or loosened. Nope, I'm not worried about the rivets.
Wanting to get something else moving, I started on the rudder upper tip by cutting another .025" aluminum strip and gluing it to the inside of the fiberglass tip piece.
With the aluminum backing strip glued in place and drying, it looks like a snowy white caterpillar. Please take special note of the extra-high-tech aeronautical clamps used in this operation. Yes, I have better clamps, but these are so quick and easy to use and if I get too much glue on them, I can just throw them away.
Oops! What are these holes. Now, I want to tell you that I have looked this part over before. Two technical advisors have looked it over and said, "Everything looks done and right." But, I was giving this thing one final inspection when I happened to notice the two empty holes. I actually would have thought they should be like that except I noticed drilled sheetmetal visible behind the tip rib. Hmmm -- to the plans.
Well, lookie here. It calls for a couple of blind rivets. That one last look at every detail quality check is really worth the extra effort. I really really thought it was all done from a riveting standpoint. I popped 2 rivets into the holes and called it finished, but I spent another 30 minutes re-inspecting the whole thing.
After that interruption, I glued the rudder upper tip into place and riveted it. All done except for the face lift it will get later when I glass over the seam for a nice clean fit.
Having a little more time, I got back to the HS tip and measured it for a first cut.
The first cut will align it with the aluminum cutout. I don't yet know if that will be enough material removed, but better to leave a little extra and trim it up when I can temporarily install the rudder and check the fit.