Did a little pickup work fabricating aileron bellcrank spacers; sorry, no pictures.

I’ve been on travel for a week or so since the last entry. I decided to work slowly, surely and patiently on the large aluminum pushrods, measuring two or three times and taking great care in cutting and drilling. The result this time was much more successful. Here’s one end of a pushrod with the threaded end match-drilled in place, done after the interior of the tube was primed.

After deburring, the threaded ends were wet-riveted in place with pulled rivets. Why the wet-riveting? Those pulled Cherry rivets are steel, and I didn’t want any galvanic corrosion working on those pushrods.

After riveting, both pushrods got a final coat of primer.

So…after those job-stress-induced issues, I ordered new parts for both the large and small aileron pushrods. Rather than go through another trial-and-error process of riveting rod-ends on the small steel pushrods, I decided to have them welded on by a local welder who does work on certified airplanes. Here’s the final product, after priming.

The ailerons went on hold for awhile as I waited for some riveting assistance. Started on the pushrods, and managed to bung up not only the small steel pushrods, but the large-diameter aluminum ones as well. Part of the problem was a simple mistake in reading the plans, the other part of the problem was more insidious. Sorry, there are no pictures here – I don’t think I need any.

The plans-reading problem was pretty basic – I forgot that following the plans doesn’t necessarily mean that all those standard-practice things, like edge distances, still apply. I fitted the threaded ends into the large aluminum pushrod tubes according to the plans, and wound up drilling holes that didn’t meet the minimum edge distance on the threaded ends. I should have been paying attention…and I wasn’t.

The second problem was the almost imperceptible rush to get something, anything, done…and that led to a lot of mistakes. My job is pretty stressful, the last two months have been worse than normal, and the next two will be worse still. That stress was bleeding over into my building, and worse, my family time. After screwing up the same part for the third time, my wife pulled me aside and wisely recommended that I slow down the project while things are so hectic…which is what I’m doing.

Primed those aileron countersinks – what a mess. That galvanized water pipe has some sort of coating that even MEK won’t cut cut throught at first. The first application of primer didn’t go so well, so I cleaned ’em off and re-shot. What fun. The little patches of masking tape cover the countersunk holes and were supposed to keep primer from gooshing out when poured into the pipe. That didn’t work as well as I hoped.

After that, I clecoed the countersinks in the leading edges and assembled the left aileron for final riveting. Sorry, no pictures of the assembled aileron.

Over the last few days I match-drilled the #30 leading edge-to-counterweight holes in the left and right ailerons. For those of you who aren’t familiar with an RV aileron counterweight (and that’s probably most of you), it’s simply a length of galvanzied steel water pipe that’s blind-riveted inside the aileron’s leading edge. Its purpose is to add some aerodynamic balance to the control surface, and to improve aileron control feel.

Nothing magical here, the only minor trick is getting everything up off the workbench when drilling these two parts in assembly because the leading edge skin is pretty flimsy and can be easily damaged by horsing the counterweight around. After drilling these holes, the counterweight is countersunk and the leading edge skin is dimpled. There’s no real mystery in countersinking the weight, you just need to know how deep to go. I went far enough so that the edges of the blind rivet are completely enclosed by the countersink; that means that the hole actually is an oval in the pipe. Sorry, no pictures of the hole – only the pipe. Use your imagination.

But how do you dimple those holes in the leading edges that will nest inside the countersinks just completed? There’s a simple trick – just cleco the weights back into the leading edges, support the assembly with a 2″x4″, and use a male dimple die to press a dimple into each countersink. Doesn’t have to be perfect, since the skin and blind rivets are prett soft and will give somewhat when riveted. To make this process easier, I stuck a #30 male dimple die into my old non-adjustable rivet squeezer set – like in these pictures.

A couple of light hits on the set with a dead-blow hammer, and the hole is dimpled. A CS4-4 blind rivet fits pretty well…

The new leading edge for my left aileron arrived today. Somehow, the part sustained a pretty good whack on one end. Must’ve happened at Van’s, because there was no damage to the shipping container. I called Van’s, they promptly shipped a replacement with no complaint.

While match-drilling the left leading edge to the countersink pipe, I managed to goober up a hole pretty badly when the drill bit chattered in the hole. I intially decided to live with it until I disassembled both ailerons for final deburring. It was impossible to clean up that errant hole wihout dramatically enlarging it and although I’m sure Van’s and most other builders would say to “build on”, I wasn’t happy with what I had. So I ordered a new leading edge from Van’s, it wasn’t too terribly expensive.

I had a bit of a hiatus on the ailerons while I was getting the wings out of the jig. Well, I’m back on them now and starting back on the left aileron now that the new skin has arrived. Got the stiffeners fabricated and match-drilled, deburred them and the skin, then dimpled same. Got the stiffeners riveted and then clecoed everything together for match-drilling…
After that, I did the same thing on the right aileron. I won’t waste your bandwidth on a pic, since it looks the same as the previous picture…only different.

While waiting for the replacement aileron skin to arrive, I started on the aileron spars and reinforcement plates. The plates are fabricated from 0.040″ sheet, and match-drilled to the aileron spars. The only trick here is making sure that the spar orientation is correct…outboard vs inboard, left vs right.
I also bent the right aileron trailing egde using the bending brake mentioned above. The piano hinge I bought at Home Despot looked to be a good idea at the time, but after a couple of bends I noticed that the hinge eyes were flexing a lot and not squeezing the trailing edge as I would’ve liked. Before I bend the left aileron, I think I’ll replace the piano hinge with regular heavy-duty door hinges.