May 17, 2009

Well, I got to spend about two hours this week on my RV-8...not a good pace. Traveled for five days, so can't do much about that, then had to compress a week's worth of "things" into a Saturday morning. I did get to sit at my workbench for a bit on Friday night, looking at the rudder plans and the rudder parts on my bench. Then I did some work on Saturday and a bit on Sunday.

The first step is to fabricate rudder stiffeners that are riveted to the inside skin. There are fourteen of them, one for each side at seven points on the rudder, and each pair is a specified length. The stock used to fabricate these stiffeners is angle stock, pre-drilled with eventual rivet holes and markings for trimming. Each piece of stock produces two or three stiffeners. I carefully lined out the stiffeners from the stock, then began to trim them with aircraft shears, as per the directions. That didn't work out too well, at least my attempts at precision cutting didn't work out too well. The upshot is that I wrecked the first stiffener I was working on....it cracked near the end. I thought about trying to make it work, but decided in the end that I'd rather just replace it.

The learning curve soared after that mistake. I realized to just make rough cuts with the shears, then use my bench sander to make the final trimming. Worked much better. Each stiffener thus needs a rough cut with shears, a visit to the belt sander, then some filing, some edge finishing, some Scotchbrite wheeling, and then a bit of clean-up. It would probably be faster to do each step to all of them at once, but working through one from start to finish breaks up the monotony, and benefits the learning curve. But, I only got eight stiffeners done (nine if you count the one I wrecked, but I probably shouldn't count that one, eh?).

8

Oh well, it is progress, and I don't have a schedule. This week looks like it will be like last week, so hopefully I'll get back to work next Saturday.

Plugged away this weekend...probably got to spend four hours on Saturday and a few other hours here and there. Not making the kind of progress I had hoped for but that's the way it goes. Too many other things demand my time right now. What I did do was finish the stiffeners, replaced the bad one I did last week, did all the prep work as far as finishing, deburring, and dimpling. They are done now.

During the process, the stiffeners were clecoed to the rudder skin for the match drilling. The stiffeners are riveted to the skin, then the rudder framework is constructed and riveted into the rudder. Here's what the outside looks like:

And here's the inside with the stiffeners in place (at least one side):

Then, tonight, after I finished the stiffeners, I began to dimple the stiffener holes on the rudder skin. Slow process, and though I wanted to prime all these parts tonight it just wasn't going to happen.

Diversions occurred, but that is par for the course. I'd rather not rush things, so I'll go off and fly away tomorrow to Colorado to work for a few days, then back on Friday. I hope to make a bit more progress on Saturday. I also want to arrange for an EAA technical counselor to take a look at what I'm doing, so I'm also working on that. I've had some good mechanics look at the horizontal stabilizer so I'm on the right track. Time now, though, to start to cultivate a working relationship with someone who knows RVs pretty well.

June 14, 2009

It's been two busy weeks since I last updated. Last week I got a few things done but ended up too busy to post anything here, not that anyone is waiting to see what I've done. But for myself, it is helpful to keep the progress current, if only to mark where I have been. I continued to work, albeit slowly, on getting the stiffeners attached to the rudder skin. I was able to prime the stiffeners and the inside of the skin where the parts met. Used my customized spray booth again (garage floor). Did that before I went off and flew for a few days...gave it time to cure, etc.

I also worked on some of the frame parts. This old R-710 part, officially known as the "rudder horn brace," has proven to be a problem for those that have gone before me, and I read with interest some of the problems to learn from prior efforts. The main thing is that if you just follow the directions a bunch of rivet holes end up too close to the edge of the part. So, I measure a few times and trimmed a few times and got close to what I wanted. Ah, the benefits of having other RV-8 and RV-7 web sites to pore over. It turned out well, but even so the edge distance is pretty tight. I'll try and post a photo of the edge distance problem later.

When you put the bottom part of the rudder frame together and cleco in the pesky R-710 part, here is what it looks like. The rudder horn is part sticking out the side, the part that will have the rudder control cables attached many years down the road. You can see here where there is potential edge distance issues with the row of rivets.

Last week, sometime around June 3rd, I was able to cleco the stiffeners into position and did some back riveting. Backriveting is actually fairly easy, as long as the parts are held flat and you can hit the shop head squarely with the special back rivet set. You lay the parts onto a heavy metal plate to provide the backing punch, then rivet straight down on the shop head.

Things went pretty quickly...too quickly I guess, as here is how some of the heads turned out.

Not sure how that happened, as I was very careful to align the tool with the rivet shank. Might have had too much air pressure on the gun. Might have had alignment problems keeping the skin pried open far enough to reach those rivets. Whatever. Bum-mer, as they say in the seventies.

So, that's how I left my rudder when I left on Thursday, June 4, to go to Manitowoc, Wisconsin, to play DC-3 for a week. More of that quality tailwheel time to make me a better RV-8 pilot, or so I tell myself. I suspect RV-8 is to DC-3 as mashed potatoes are to clutch discs. But delusion is okay as long as I think it's real.

Anyway, got back to the project this past weekend, spent maybe four hours on Saturday and another two today, Sunday. Here and there, around mowing lawns and taking care of stuff. And, saying hello to the family as I drop by for a visit, or so it seems. So I got to drill out quite a few rivets...getting good at that. Not too bad, actually. I have found if I center punch a point on the rivet, then drill a pilot hole, I can then use a drill bit a bit bigger and drill it square on the center of the rivet. That usually takes the factory head of the rivet off, then I can use a pair of dykes to pull the shop head out. Usually works; I'll shoot some pictures next time I do it which probably will be soon.

So, I got the bad rivets out and back riveted in some good ones. Not 100% good but meets my personal standard which is picky enough, or so I think. One can use special rivet tape to hold the rivets in place while they are inverted onto the back rivet plate, which is what the green tape strips are doing in this photo.

Then I had to rebend the trailing edge back to approximate the angle needed to fit around the rudder frame. Van's suggests a bending brake made of two 2 X 8s and some hinges. Built that...worked okay but not great. End result after tinkering a bit made the whole thing work out okay.

Then I did the match drilling on all the rudder frame parts, then clecoed on the rudder skin to the rudder frame. That's as far as I got today. Next up: match drill the skin to the frame, then take it all apart. deburr a lot of holes, dimple here, dimple there, edge finish, prime what needs to be primed, then start riveting this baby together. It's going to be awhile.

Also, I'd like an EAA technical counselor to look at these parts before I rivet them together. Get a second set of eyes, one's that know RV-8s and can give me some good advice. I've got a guy in mind; we shall see if he is of a like mind. That's it....

June 28, 2009

Another two weeks flew by just like that. Too much going on, but that included some family time as my youngest turned the ripe old age of 21 years. Okay, all three boys are over 21 now so I am completely done being a parent...finis...no more worries...more time to build airplane.....right. But the whole gang went to South Lake Tahoe last weekend for a good time but no airplane building. Then I flew last week...no airplane building. Just a bit here and there, then hit it pretty hard in the last two day. Got some stuff done.

In the period leading up to this weekend I did do the match drilling of the skin to the understructure. This included the parts I fabricated that will someday allow the fiberglass rudder bottom piece to mount to the rudder. It is clamped into position and then match drilled.

Then I did the finish work to the parts....deburred all the holes, edge finished all the edges, smoothed out all the stuff, dimpled all the skin holes and the matching parts on the understructure. That I pretty much did yesterday (Saturday) when it was, like 102 degrees in Lincoln and hotter yet in the workshop (garage). Not too bad but I did sweat a bit. Then, it was off to my spray booth (garage floor) for a coat of primer.

Today, Sunday afternoon, I clecoed the understructure back together and thought a bit, and double checked everything, then did some riveting. Screwed it up, naturally, and riveted the nutplate on the wrong side of the spar. This is the "before" picture, "before" I riveted it and then "before" I drilled out the rivets and "before" I did it again.

Okay, now we are making progress....here is the bottom part of the understructure completed.

So as the day started to wind down, I had to move on to some other things that demanded my time, but all the nutplates and spar doublers are properly riveted.

I just need to rivet the rudder horn reinforcer in and the understructure will be complete. Then the skin is fitted and riveted and more stuff is done and then the rudder is done. Next weekend. Fly again this week....Beech 300 King Air this time. No tailwheel.

As a parting shot, I had requested photos a few months ago and Ron Snyder had sent me this one of him landing his RV-8 at Smoketown, Pennsylvania. I forgot to add it in so I'm adding it here as an inspiration. Cool photo, eh?

Until next week, then.

July 12, 2009

Well, instead of finishing the rudder here, I've started the elevators. This is because I wanted an EAA Tech counselor to look at the rudder innards before I rivet the whole thing together. He did so yesterday and found things to be where they should be. However, he advised me to bend the rudder skin tighter so there would be absolutely no tension on the part...keeps the trailing edge from developing cracks. So, another helpful RV guy (Keith) offered to help me with his shop setup to do the final precise bend. But, alas, I will wait until I can bend both the rudder and elevator skins...some weeks in the future. That's okay...still making progress on the elevator instead.

Augsut 15, 2009

I had set the rudder aside in July to await the bending of the rudder and elevator skins, and during the wait time I dove into the elevators. I was finally able to take Keith Peterson up on his offer to help me correctly bend the rudder and elevators skins. During my EAA Tech inspection held last month, Keith came along for the ride and noted that my rudder skin was not bent far enough, then made the generous offer to show me how to bend them. Week before last I threw the skins into the Voyager and drove up to his house/shop/hangar at Nevada County Airport at Grass Valley. Took about an hour to do a nice job using some big angle iron and some clamps. Now I know how to do it. The wooden bending brake wasn't workig out too well for me, so now they are done correctly. Bent the trim tab also, just for good measure. I wish I had some photos of that process but, alas, I don't.

So, I got the skins back to my shop and set aside the elevators and went back to finish up the rudder. The skin had already been prepped so it was just a matter of sliding the skin over the completed understructure. It fit like a glove so I cleoced it all together and started to rivet it up. Followed the directions, of course (see later).

All the rivets at this point are squeezed. These four rivets I thought might be a problem.

But, using the longeron yoke, I was able to easily squeeze three of them. The fourth one, the one closest to the spar, proved to be a bugger because the nut plate for the bottom rudder hinge gets in the way. The plans say you can either use a squeezed or a pulled rivet for these four. I read some other sites and some comments about this rivet and decided to wimp out and pull a rivet both here and at the other end where things are pretty tight to get any kind of squeezed rivet in.

So, here is the rudder with the skin just about on.

I mentioned earlier about following the directions, and I really did follow them. After I got a dozen or so rivets on the skin done I was looking at the plans and saw that the callout for the rivets holding the top rib to the spar were squeezed. This surprised me a bit because there is no access once the skin is on. I had figured they would be pulled rivets like on the middle rivets on the horizontal stabilizer but, no, they were supposed to be squeezed. Bummer.

I scratched my head a bit and re-read the directions. No where in there does it ever say to rivet that rib to the spar. I consulted with "my people" and decided two Cherry Max rivets would work just fine there. Better than trying to drill out a dozen or more rivets. And it did work out just fine.

Then, we got into rolling the leading edge of the rudder. Followed the directions (again) and it worked out pretty well. Got my pipe, got my Gorilla Tape, got my son helping. Rolled that baby up. It wasn't as neat and/or clean as I had hoped, and it seemed like it would not go together well for the last half inch.

Did some more research on line. Determined that a bit of shear pressure on the seam would not be a problem so I started popping rivets.

Turned out okay, I guess. Not perfect, but pretty good. Seemed like more bending near the edge of the rib that I cared for but I don't see how else it could be done.

So, the next step is to do a rough attach of the rudder to the vertical stabilizer. Install the hinge bearing mounts into the rudder and fit them to the hinge mounts on the stabilizer, then adjust to the right gap between the two surfaces. Check for binding of the rudder. So I laid the rudder down next to the vertical stabilizer. Hey, an airplane tail just appeared. Pretty cool.

I studied the plans again carefully and noted that the bottom bearing mount is longer than the other two (the other two being the same part number as the elevator bearing mounts). Test fitted it all together, then constructed this little tool to screw the bearing mounts into the nutplates without damaging them.

I'd like to say I made up this tool, but I'm not that smart. Toad's page (an excellent help to me) on the subject pointed to Sam Buchanan's ideas on the matter. The worldwide web: couldn't build an RV-8 without it and all the guys who have done this already and have well documented it.

Well, I was all ready to adjust my bearings and my gap but I ran out of Sunday before I ran out of things to do. I shall return next weekend and finish the rudder up.

Augsut 23, 2009

I got back into it on Saturday and was finally able to finish up the rudder except for the fiberglass work, which will be done either sooner (if I have spare time before I start on the wings) or later (when I can get to it later). I suspect the former will prevail. I spent a bit of time figuring out how to adjust the rod end bearings. The depth is adjusted by tightening or loosening the bearing threads until the right gap exists between the rudder and vertical stabilizer. Took a bit of hit and miss. Not sure if it is even correct now. I shall have to take one more look at these after I talk to someone who knows what they are doing.

Here is the rudder and vertical in the middle of said adjustment.

And, after all was said and done, I had to do the requisite "stand them on the table" shot showing the vertical stabilizer with rudder attached. Had to show my son, make airplane noises, move the rudder back and forth repeatedly...all the normal stuff.

On to the elevators.