Stjohn's RV-7

This is evidence of the fact that I can’t count holes, and should have been looking for a pattern. the Left HS hinge brackets not only have the manufactured heads on the wrong side, they’re in the wrong place as well.. The outboard bracket is ten, count ’em TEN holes from the end of the reinforcing bar. This bracket is at nine. Grr. Double Grr. So today I decided to drill out and redo the rivets, because something tells me I don’t want this particular sandwich to lose its tomato in flight. So drill them out I did, but this is where the double-grr comes in. I put them back on exactly as they came off, but not before I realized the position was wrong. So I drilled them out again. Rivets don’t like to come out of that angle steel nearly as easily as they pop out of aluminum, so I had to drill them out, and in doing so, enlarged the holes past the point of being able to safely take a rivet. Fmmkgrmmbllefffmk. Just ordered my first oops parts from Van’s. I’ll take a couple of HS412-PP’s to go, thanks.

6 Hours
Ahh. Significant progress, finally. Today, I actually RIVETED SOMETHING! But I’ve got some pics here, so I’ll just go through them.

This is the VS bits, ready for prep, and the big giant bitchin tool chest upon which they sit is already worth its weight in, uh, stainless steel. The drawer that’s open there is the drill drawer.

First evidence of priming. For the record, I HATE priming. It sucks. I’m going to prime as little as possible, because it’s messy, complicated, time-consuming, environmentally unsound, and hazardous to your health. I’m going to put my faith in Alclad where it exists, because it’s going to be a better protector of metal than any prime job that I’ll give it. Having said that though, I found a nice primer that’s real close to the color of the dropship and the APC in James Cameron’s “Aliens.”

Some more bits. I remember reading in the construction manual somewhere that it’s OK to scribe part designations into the metal. That’s what I did, because this nice, friendly, USCM-issue self-etching primer covered up the sharpie marks pretty well.

The blue thing in the upper left corner is the Rose Bowl swap-meet HVLP gun I picked up for 28 bucks. The manual was interesting; it read like it was translated from another language by a computer and transcribed manually by someone who spoke a different language altogether. Didn’t matter though. It didn’t leak and shot half-decent paint, after some work dialing it in. That’s what the various patterns below the dartboard are.

OK, here’s everything, looking good, let’s rivet it… Crap.

Before we get too ahead of ourselves, let’s dig the HS reinforcement bars out from behind all the other crap and paint them too. Grr.

First Rivets! Well, second rivets. And they’re WrONG! yippeee! Supposed to put the shop head on the side with the thicker material. But I used my lifeline. Dan C said it’s probably OK to do it this way as long as the metal on the other side doesn’t get distorted, which it didn’t, except for one rivet, which I later drilled out and re-did. That little sharpie graffito there that says “Every Move a Picture” is a band I heard on the radio, and I didn’t want to forget what it was so I wrote it down on the worktable. It’s good stuff, sounds a little bit like Joy Division without the death, New Order without the whine, and early Duran Duran without the hairspray.

Smiles, everyone, Smiles! Still riveting arse-backwards at this point.

Hey, now that’s got it! Thanks Dan! using the C-frame actually kind of rocks.. almost hands-free, but I think it’s now time to revisit the pneumatic squeezer, squeezer sets, and squeezer yokes. I’ll need to pick up the adjustable piston, a few flat and cupped sets, and a couple of yokes, namely the 4″ and the longeron yoke.

Here, we’re looking at the aft HS spar put together (except for 2 bad rivets I have to drill out) and the beginnings of the forward HS spar.

And here’s the HS spars, riveted! badda boom, baby.

2 Hours
YAHoo!
With a working Burraway, I finished deburring and dimpling all the VS ribs, skin, and spars. Also went to the paint store and got some self-etching primer, plus some solvent wash. Still need to deburr the VS skin edges. Raining today, so painting’s out. This sucks, I wanted to be riveting the HS and VS skeletons by this afternoon.

A side note on the Burraway. What happened originally was that I snapped the blade in half trying to mess with the tension bolt in the end of the tool. So then I had to change out the blade. If you recall, there is a pin that goes through the shank of the tool that holds the blade in place, and it’s one of those tension pins that’s basically a metal tube split down the length so as to put tension on the hole it’s inserted in and to hold the blade in place. You find them more often in things like watches. Well, when I drove this thing out to replace the blade, I didn’t really have the type of precision tool to do this correctly, so I raided my wife’s sewing gear (her craft room rivals my airplane factory in complexity and scope) and used a big sewing needle to push the pin out. This was all dandy, except with the new blade in, I couldn’t compress the tube-pin and get it back in the hole. Enter the needlenose pliers. Small ones, but not small enough. I managed to mangle the pin quite nicely before trying to shove it back in there. Of course, now I was hosed. 2 spare blades, no way to secure them to the Burraway’s shank. Actually, Cogsdill Tool recommends replacing the entire fitting and keeping the arbor, which is where the tension spring and pin are. Unfortunately for both Cogsdill and me, MSC carries either the blade or the whole tool, but not just the shank-blade part in assembled form.
It’s amazing how the monkeybrain works sometimes. I was standing there in the garage, when the idea hit me like a 1x4x9 monolith. The sewing needle I used to push the tension pin out of the shank was about to get repurposed. With the needle through the blade and the shank, I put the whole tool back together and it worked, since the spring tension on the blade was enough to hold it steady in the hole and let the blade work properly. Woohoo! Success. Except now I had two great lengths of needle sticking out to either side, which probably would have been all right if I was careful enough, but a sewing needle spinning at 3000 rpm somewhere near where I’m putting my hand to hold work steady wasn’t totally cool with me. Enter the wire cutters. With these, I cut off the needle as close to the shank as I could, but there was still a little bit sticking out, which went away with a little bit of Dremel work. I was ready to go. I tightened everything back down, but something must have come loose, causing the pin to fall out and the blade to go pinging across the garage, never to be seen again. It looks like a metal shaving, so lotsa luck finding it. No matter. I had another spare blade. Repeated the above process, and this time it worked great! My Burraway was back online. The idea with this thing is to keep it from carving away too much metal, and you want to put just enough tension on the blade so that it compresses after it’s removed the burrs and made the chamfer. Too much tension and it makes a #30 hole out of a #40. Not enough and you still got burrs. Too much tension also has the effect of snapping the blade in half, as we learned earlier, which is exactly what happened. But now I was out of blades. I will defy any dockside brawler to match the swearing that came out of the garage at that moment. Back to the computer. I wasn’t about to fork out another fifty bucks for a new Burraway, but I could spend that on 5 replacement blades and not feel too bad about it. That was a week ago. Now, knowing what I know, the Burraway is once again earning its keep.

Actually got a couple of hours to work on the plane.. Or so I thought. fixed my .093 Burraway, but after a few runs on the HS aft spar, the blade broke. This wouldn’t have been quite as frustrating if I hadn’t previously tried to fix it and had the spring tensioner pop the blade out and fling it across the shop into some nameless nook (yes, the shop shares space with laundry machinery and some wood). It also looks a lot like a metal shaving, so searching for it was going to be interesting. Well, screw it, I thought. Nothing to do now, but buy stuff. The new tool chest rules. I now have everything put away in a drawer, and my worktable no longer has to share space with my old toolbox, which can now contain all the usual home handyman stuff. I was able to move all my compressed-air and paint stuff out of the storage cabinet that holds the woodworking, tile, and other home-improvement gear. So that was nice. And when my spare Burraway blades come in from MSC, I will remember not to tighten the tensioner so frigging tight.

2 hours
final-drilled the VS skin and took it apart for deburring/dimpling. Then it’s time to prime. Really need to get it together with the whole air line thing so I’m shooting dry, clean air. I have a special hose for paint, a 4-way regulator, and a filter. I am going to have to bite the bullet and set up air channels in the garage this weekend.
pics to follow.

Clecoed the VS skin to the VS skeleton in preparation for drilling.
I already miss my .093 Burraway. Should have the VS ready for priming by the end of the week.
Here before you is the VS, clecoed together:

finished drilling and assembling VS skeleton. Now on to the skin, then we’re in primer hell.

Finished dimpling/deburring the HS. Not without a couple of glitches (Cframe == evil), but that section’s done. time to prime the primable parts.
Or maybe not.
It looks to me like priming is a huge pain in the ass, and I don’t really have the talent or the facilities for it, except in the most makeshift way. I don’t want to spend any longer on it than I have to, but I definitely want to break out the flea-market HVLP gun and see what I can do. So my plan is this: do the VS assembly/drilling/deburring/prepping, then prime the HS and VS at the same time. I’m not going to prime the skins. All I really care about is priming the vulnerable stuff, like the reinforcing angles and maybe the VS doubler. I’m not terribly worried about where I drilled the holes for the skin rivets because a rivet is going to seal up that metal better any any coat of paint.
So that’s what I did today: edge-prepped the VS spars and ribs.
I know this is building out of sequence, but unless the work takes more time than the prep and cleanup, it offends my sense of efficiency. As it is, shooting paint will be the least part of it, but I want to spend as little time doing it as possible.

8 hours.
Managed to get a dimpled skin and some ribs out of it.

Whole lot of building and not a lot of photography today. Drilled, disassembled, deburred, and dimpled right side HS today. I got to use my pneumatic squeezer. A lot. I clamped it in the vise for a little improv bench squeezer action. Ribs and spars ar a lot lighter than the squeezer, so this make things pretty easy.

I also dimpled the HS601PP skin using the squeezer freehand, but had to go to the C-Frame for the deep-reach stuff. I have to tell you, using that C-frame dimpler is a royal pain in the ass. The DRDT-2 is the way to go, or just welding up a big box-tube copy of it and finishing it in such a way that you can use the squeezer for the dimpler’s motive power. I have a design in my head, but I don’t need to go into it here since I can’t weld and I’m going to get all the mileage out of this Avery C-frame that I can. However, if you don’t position your workpiece correctly or you take your eye off it for the amount of time it takes to line up the hammer blow, your skin could jump off the dimple punch and put a hole somewhere in the vicinity of the one you actually want to dimple. Like so:

Well, that totally sucked. Not replace-the-skin sucked, though. The rivet is on the bottom side of the HS, and I did manage to drill it out to 1/8 and I’m hoping the rivet seats and covers up the slight elongation of the hole.
Eventually I got all the ribs and skin dimpled for the right HS. Deburring was not bad, just tedious, made even more so by this:

The black probelike thing is a Cogsdill Burraway, .093 size. The little silver sliver next to it is the blade. The idea behind this tool is you put it in a drill motor and run it through the hole you want to deburr. The little blade sticks out to the side of the shaft and deburrs the hole in one pass, outside on the way in, inside on the way out. In theory. Problem is, the .093 is just a wee bit too small to be effective on #40 holes, especially ones that are a little on the big side. This led me to try to adjust the blade tension. I subsequently broke it. So now, I have to find a frigging watchmaker to replace this blade. This tool is so small, it’s impossible to modify with the stuff I have. This pic was shot through my magnifying-glass desk lamp out on the workbench. However, the 1/8 size Burraway is great. Go Cogsdill! What I need to do now is get online to MSC and order a new retaining pin, and a bigger blade, if they have it. This little bastard was $55 bucks, so I’d hate to think it’s useless. Tomorrow we make sure all the edges are done (sometimes I miss things) and move on to the Left side HS.