So here we go. Finally the iPhone and its apps have caught up with my needs and skills. I give you… The direct post!
Anyway, this is me, riveting the left bottom wing skin on. I’m doing the row just outboard of the autopilot, which you can see in the lower left of frame in that dark compartment.
7 hours.
Yesterday, my friend Derek came by for a few hours and helped me rivet the bottom wing skins on. Derek is peripherally responsible for me being where I am today with regard to aviation: Flying leads to skydiving, skydiving leads back to flying and flying lessons, rental airplanes lead to homebuilts. Before he arrived, I did some pondering about the best way to rivet the wing skins on, and the first two things that needed to happen were the removal of the aileron push tubes and the flaps, so I did that.
Riveting the skins on the wings would have been really tough without help, especially the inboard rows near the bellcrank. As it was, I really had to stretch to get the bucking bar up in there far enough to reach the rivets closest to the aft wing spar. But it gets easier as you move outboard, and we finished off the left wing yesterday afternoon. Derek had to leave at around 3-ish: newborns really don’t care all that much about Daddy’s friends’ projects, but I kept going.
Before he left, Derek helped me get the double row of rivets on the right wing, then I got going on the rest. To say that riveting those big bastards by yourself is awkward would be like saying Stephen King sells a lot of books. Fortunately, the skins do bend quite a bit, and I wish I had a photo to show you how I did it, but the general gist of it this:
With the double row riveted, cleco the spar side and leading edge side holes together. Then climb in between the skin and the ribs, which will allow you to get a hand and a bucking bar in through the lightening holes to just about anywhere you need to go. And it should go without saying, remove the blue stuff from the inside of the skin before it gets riveted on, or you’re going to have a lot of fun later. Good thing I remembered this before we got too far along, but if you’re reading this, I hope it reminds you before you buy yourself a long night of failure-drinking.
I thought the autopilot servo was going to cause a lot of problems, but with the push tubes out of the way, it was really a non-issue. By myself, I got another row done, up to the access panel for the bellcrank, then quit for the day. I was sore and tired. Even with help, riveting wing skins on is like yoga for gearheads.
Left to do: the remaining skin rivets, and some minor wiring cleanup, since I replaced the puny 14-ga wire intended for the landing lights with a much beefier 10-ga flavor.
4 hours.
A few things here and there. I installed the MAP tubing and put a couple of heat shields on the pipes to protect the throttle and mixture cables. I also installed the canopy seal, which is going to need some assistance from some RTV or proseal. I do think firewall forward is just about done, though. The cabin heat SCAT tube rubs on the engine mount a little, but some UHMW tape should fix that. The two things I did that were of major importance were the autopilot test and getting that ridiculous piece of lead off the flange of the left elevator counterweight rib.
A while back, I’d balanced out my elevators, or so I thought. You’re supposed to put the elevator tips on, then drill holes in the lead weight until the elevator balances. Well, guess what? You’re not supposed to have the elevators connected when you do this. I discovered this, freaked out, then riveted a flat piece of lead (cut from an extra counterweight) to the outboard rib.
When I put that away, thinking I was just about the smartest cat in the whole barn, I started imagining the kind of beating a control surface takes in flight. So what happens to a little piece of lead riveted to this structure with a couple of Cherry countersunk blind rivets? The piece of lead comes off and somehow jams the elevator in the dive position and I go screaming downward like a holed Stuka, straight into a busload of orphans on the 405. This has bothered me for months, but I could never find a good opportunity to fix it until Saturday. I drilled out the rivets and put the lead back in a drawer. I also read about a neat trick you can do when balancing your elevators: Pour some lead shot into the tip through the tooling hole in the rib until th elevator balances out, then stick it in place with epoxy resin. Even if it’s not perfect, bias it a little heavy, because paint will change the balance.
I also mounted the MGL GPS antenna on the top side of the glare shield. It works; I get an intermittent GPS position while still inside the guest house.
Oh and one other thing: I dragged the wing cradle over to the shop and tested out the bank servo of the autopilot. Since I actually followed a wiring plan and wired the fuselage-side and the wing side according to it, I was able to test out both servos simultaneously. I do need to make a new ground connection though. The ground from the servo bracket sucks and I was only able to get a good ground by cleco-clamping the ground terminal to a wing rib.
4 hours.
I took a drive down to Earl’s on Hawthorne at the 405 freeway to pick up the fittings I need to plumb the purge line. I wanted to save the 11 bucks for shipping, which is ricockulous considering it’s all of 15 miles away from my house. I’m glad I went. The place is an absolute gold mine of high performance vehicle plumbing. They have everything, including the weird stuff, and best of all, they can custom-make hoses while you wait. Still a pricey run. The stainless steel bulkhead elbow for the firewall was not cheap by any stretch. After I got back, I pulled the wings out of the garage to finish up all the old business, which was fabbing conduit support angles, installing Adel clamps, fitting and plugging in the pitot tube, and wiring the autopilot roll servo. I also spent a good amount of time rubbing off old masking tape glue with MEK. Don’t leave masking tape on anything for too long, especially in a hot, dry place The tape turns brittle and the glue turns solid. On the right wing I got wise and heated up the old tape with a heat gun which let me get most of it off in one piece. The rest came off like the stickers Van’s still puts on every part, which never peel off cleanly. This process took a while and by then I was completely beat. I only got 4 hours of sleep last night for some reason, so I was a zombie all day. I figured I’d nap for an hour and go back too it, but I started reading the last chapter of William Gibson’s “Zero History” and I was asleep before the end of the first page. I woke up two hours later, still exhausted, but I went back out there and wired up the autopilot pitch servo.
Both autopilots got wired using the D-Sub method: Use barrel-crimp d-sub pins and sockets on the wires, then individually shrink-wrap them, then put a big shrink tube around all of them. I did this for a couple of reasons. First, the Molex connectors didn’t have a decent locking mechanism. I’m sure it’s fine, but I didn’t like it. Second, I somehow lost a couple of the pins. Embarrassing, but whatever, this should work fine.
I didn’t get around to plumbing my purge line, and common wisdom seems to be to wait until the engine is hung for this. But the longer I wait, the more stuff is going to be in my way when I do a triple-bypass on the fuel system, so I want to get the tubing roughed in as much as possible.
6 hours.
I finished up the pitot heat stuff, got the heat module mounted and the wires spliced in. When I get the Adel clamps from spruce, that process is done and done. It doesn’t sound like much, but it took some time. I had to use platenuts because I have to plan on an extremely limited amount of access once the skin is riveted on. And as an added bonus to my day, I found that some condensation or spray from the hose left some kind of deposits all over my left wing. This sucks. I might be able to buff it out, but it looks like the lime or whatever is etching the alclad. Flat Olive Drab paint it is.
I also got the MGL com extender mounted, and got a good start on mounting the IO extender, but the 6R8 screws I have are too short, so I need to get some longer screws from ACS. Always with ACS. I want to finish this plane so I can stop buying stuff from them for a while.
5 hours.
Yesterday, I should have stayed in bed. It was that bad. I started out the day by attempting to mount the RDAC (engine monitor module) on the firewall. I did this by drilling out one rivet in the F-601L stiffener along the top of the firewall, then match-drilling the rest of the holes. Would have been a great plan, except when I was drilling the second hole in the firewall and stiffener, something moved and I put the hole about 3/32 of an inch below where it was supposed to go. Boom, violated edge distance. I have an email in to Van’s tech support to find out whether I’m going to have to replace that stiffener, which would suck like nothing has ever sucked before. It would involve removing the engine mount and the landing gear. The other possibility, since I’m not really placing a load on the stiffener with the 5-ounce RDAC, is that they’ll tell me to “build on.” If that happens, I just have a slightly crooked RDAC, but otherwise it’s fine. So I’m kind of freaking out about that, and really hoping I haven’t bought myself a ton of work with this one stupid mistake.
Then it started to get better: The LA public library emailed and said my copy of William Gibson’s ‘Zero History’ was available for pickup, so Shelley and I rode our bikes down there to get it. But on the way home I almost got run over by an idiot backing out of the car wash. What does this have to do with airplane building? Not much, other than it’s difficult to work on critical things in a state of elevated stress. But I needed a win of some kind, so I decided it was time to mount the heated pitot tube in the wing. Of course, that ballooned into wing wiring.
This pic doesn’t show the tubes, but I originally had the AoA and pitot lines running through the two grommets in the rib in the bottom of the frame.
But it’s a couple of years later, and I now know a lot more about EM interference than I did back then, as well as what equipment I’ll have on board. I pretty much rewired the whole thing. First thing I did was pull out all the wires and cut a section in the PVC conduit to allow the pitot heat wires and AoA tube an exit to mid-wing. I rounded off the edges of the PVC to mitigate chafing, then ran AoA tube, NAV antenna wire, pitot heat, landing light, and position light wires down the conduit, breaking out the pitot heat wires and the AoA tube, while sending the rest down to the wingtip. The strobe cable I ran through one of the grommets from wing root to wingtip, which will help isolate the strobe pulses from the NAV antenna. Supposedly RG400 cable keeps this from happening, but I’m going to be making a lot of connections at the wing root (building in the guest house, remember?), so I want to keep the strobe cable and the antenna as separated as possible. Unfortunately, I can’t close the deal, because I need two more 1 1/16″ Adel clamps for the cut ends of the conduit, otherwise they’ll vibrate against the ribs. Those should show up from ACS in a couple of days, but it really irks me to leave things unfinished because I don’t have supplies. It makes more to double check later.
The other wing got the same treatment, but I’d already cut a break in that conduit to allow for autopilot wiring. I still ran the strobe cable through the grommets near the spar, because I’m not terribly interested in having the strobes make the autopilot twitch. Also, depending on the performance of the Archer NAV antenna, I might put another one in the right wing for a second NAV radio at some point.
After all that, I didn’t get the pitot heat module actually mounted. That’s next.
1.5 hours.
Cut and glassed in the emp tip foam inserts. This damned foam took nearly a month for Aircraft Spruce to get it to my house. It was backordered, then backordered again, and I finally got it today. They sent me a 2×4′ sheet of it too, and I’m pretty sure I ordered a lot less of it. Oh well.
This was easy enough, cut out some foam bits that fill the shape of the fiberglass tips, closing them off to outside elements. Mostly. I applied fiberglass and foam with the tips clecoed on so when the resin dries, I can pull them off and the tips will stay the shape they where when clecoed on. A couple of layups on the inside of the foam block and some micro filler frosting on the outside and those will be done. Then I don’t have to see the empennage again for a while.
Since I had some resin in the pot, I used up all the rest of my cut scraps to glass in the Archer VOR antenna in the wingtip, something I’d been planning to do for a long time but never got around to it. I did two layups on that, which should be enough to hold it in place, it’s not structural, just something to keep the antenna from flopping around in the wingtip. Another thing done.
4 hours.
Finished the platenuts in the left wing. Other than a slightly messy install of the trailing edge platenut, the process went OK. However, for the first time, I regret not getting the platenut jig for the 8-series K1000 and K1100’s. I still have to figure out what to do about the wiring that’ll eventually go through the fuselage to the panel, but I there is no longer any interference with the control tubes (yeah, that was a big one, glad I caught it now). The wings are now back in the little garage for storage until they go to the airport.
So what next? The engine is supposed to be next, but I need the space and tech to fix a busted motor mount on my Buell, which is my daily transportation. However, I am dying to find out just how bad my motor is inside. Here’s hoping the guy who stored it for 10 years stored it properly and I don’t have a rusted camshaft.
9 hours.
I’d say that only 7 hours was actual, tools-to-metal building. The rest of it was cleaning the shop, looking at plans, arranging parts, and various distractions. I’m also including Wednesday night, when David came over and helped me with the final wings-on/wings-off activities. We drilled the wing root fairings and the bottom skin, then pulled the wings off and moved the plane back into the guest house. Then I slacked off for two days while I took a break and watched bad movies.
Today, I got back on it and tried to get the wings into shape for more cold storage. Because I’m an idiot and didn’t attach the pitot and static fittings, the AN connectors slid up (down?) the tubing of the pitot and AOA into the pitot mast and got stuck there, with no way to wiggle them loose. I had to take the pitot tube off and shove the fittings down to the point where I could grab them and hook them up to the plastic tubing running down the wing. Of course, this demanded that I unclamp the plastic tubing from the Adel clamps attached to the bellcrank bracket to give it some slack. Finally, I got all that back together, ran my wires back down the conduit, and moved on.
I deburred and dimpled the wing root fairings, and deburred/dimpled/countersunk the wing roots. I also drilled all the holes for platenuts. I got all the platenuts done on the right wing, which was slow going on the forward edges because they went family style on the pro-seal. It also didn’t help that I drilled the fairing root holes a little too close to the root rib. I had to grind down some of the platenuts so they’d lay flat on the skin. But it’s all good, they’re all installed. I’ll do the left wing tomorrow, then they go back into the garage to await the trip to the airport. And some wiring. And some other stuff.
8 hours.
Saturday was a pretty huge day in its own right. The night before, I’d cleaned up the workshop and put all the tools away so I could start making a fresh mess. I gloated over my handiwork in drilling the wing spars for a few minutes, then got going on the flap rigging. The flaps are attached at the trailing edge of the wing with a strip of piano hinge. The right side, the inboard edge of the flap rubbed against the fuselage, which didnt allow it to travel its full range of motion. So off it came, and I filed and scotchbrited off enough metal so that it did. However, in that sentence is contained about 4 or 5 iterations of trial, error, and scratching the crap out of the flap with the file until I got smart and put some tape around where I’d be working it. Eventually, it fit fine and was able to swing up and down, and in the ‘up’ position, the skin lay flat on the belly. The left side wasn’t a problem.
After that, it was time to reinstall the flap motor and rig the flaps. This is where the first setback occurred. The flap motor was one of the first things I did on the fuselage, so maybe I screwed it up, but there are many reports of the flap motor channel interfering with the canopy latch bar. Supposedly, they fixed this in the matched-hole kit, but I have a matched-hole kit and I’m telling you now, it ain’t fixed. What I had to do was put a 3/16″ spacer between the bushing block and the F-705 bulkhead to move the canopy latch bar forward enough so that it would clear the flap motor channel. I also had to change the rivets on the upper part of the flap motor channel to flush AN426 rivets. After this, I was able to see daylight between the latch bar and the channel. Of course, this also meant that the pushrod between the latch handle and the bar was now about 1/4″ too long. Put that on the list.
Then came the weird ceremony of drilling the flap pushrod holes. I”ll post pictures of this whole mess when I get the chance.