I dove back into the push rods, wanting to get them finished up from yesterday. The pull rivets in the larger, long aileron push rods were a piece of cake and I got those done no problem.
Then I tackled the smaller ones that go from the bell crank to the aileron. They get one AN470 4-12...this is the one that some builders weld instead of riveting. Well, let me say I dont regret trying to rivet them because I did get one rod done...but its really kind of a bitch and you have to be real careful when doing this. Since its such a long rivet and you're trying to rivet onto a round surface...it really doesnt want to cooperate.
I did 3 of the 4 successfully, but the second one I attempted gave me trouble. I drilled it out and tried again...crap, screwed it up even worse. Tried to drill it out a third time and it was toast! Oh well, as I always say, its not the end of the world....mistakes happen. I'll order some more material and give it another go.
By the way, this was my process for the successful ones. I used the drill press with wood blocks to hold the rod in place and keep it centered (you can buy nice 'V' blocks to do this properly). This wasnt too difficult, but just go real slow and easy to keep it straight. Then I cut the -12 rivets down just slightly with my rivet cutter (I think they are a smidge too long for this task). Then I used my rivet gun and my back rivet plate as a sort of bucking bar. This worked pretty good if you can keep the rod nice and square and go slow. That rivet wants to bend over...dont let it. ;) Anyway, up to you if you want to go this route or weld. I could certainly see the argument for welding as this will challenge your machinist and riveting skills.
[Edit 01/17/11: did some research on VAF after the fact . Seems most guys will just clamp the rod in a vice and then buck the rivets with the gun...some guys also squeeze them, not sure if my pnuematic squeezer could handle such a long rivet? But both of these sound like fine ideas. I also noticed some discussion about using an alum alloy rivet in steel parts which is a valid point. Right now I dont plan to redo mine with different rivets...I mean Van's specs alum rivets and there are 7000+ flying. But fundamentally from an Engineering standpoint its a flawed design. It will certainly be something I keep an eye on for corrosion during inspections. In addition, I plan to primer those rivets to create a moisture barrier. It wont help with the dissimilar metals problem, but it might help overall.]
Using my handy paper again, I did a layout for the 6 equally spaced rivets around the rod. Using the paper get a measurement for the circumference, then lay your paper out on the table, do your arithmetic to equally divide the distance and draw index marks on the paper. Roll it back onto the rod and voila...you have now transferred your layout to the round rod. The paper also will keep you nice and square to the end.
You can see here in this pic, even though I call this a successful rivet (the shop head measures to spec), you can see its still not very pretty. It just doesnt want to conform to the round tube very well. Oh well I'm not going to sweat it, its not going anywhere. This at least gives you an idea what my results look like for comparison to your own.
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