Wings 4
2/12/2006 9.5 Hours
Today was the day that the wings go on for good. The first obstacle to overcome though was the fuel senders. Now then what a malady this turned out to be! Steve came by today too, to help out with getting the wings on. I guess it may be possible to do them yourself, but I sure wouldn't like to try it. For me, this is a two person task for sure.
So, back to the fuel sender thing. Well, it's a bit embarrassing really, because we looked at it, and for some reason I had it in my head that the fuel tank access plates were wrong. It took us a while to figure out that they were in fact absolutely right. We only discovered that they were right after we erm, disassembled them and then tried to figure out making some new ones. It was then we realised that the actual senders were handed too. What kind of drug was I on the other day?! Well, our moment of clarity was instantly mudded when we had to break out the cancer (Proseal) and re-assemble the darn things! We wasted a lot of time today mucking about with this thing. Way too much time in fact. Doh!!
Anyway, all is right with the fuel sender world now. While we had the Proseal out (we would've had to mix some eventually anyway) we put the senders in and the tank access plates went back in the tank. We threw out the rubber gaskets for the senders and the cork gaskets for the access plates in favour of using Proseal instead. Might be harder to prise apart for service, but these things shouldn't need too much servicing. I forgot to take a picture of them all in place. That stuff gets everywhere. Once it touches something, before you know it, it's on everything. Hence the nickname "Cancer". Lovely stuff.
We moved on to final prep for putting the wings on after the earlier debacle. I'd painted the gussets earlier today too while we were messing about with the fuel sender stuff, so they were ready. We put the nutplate on the one access panel cover under each wing that was left. We filled the little starter hole in the fuselage floor (for the -A models gear legs) with a rivet, and put the gussets in place.
We then threaded all the cables through the conduit. Something I need to test is strobe noise. Right now, I've put all the cables through the conduit, antenna, strobe and all. I'll connect them next hangar visit and turn the stobes on to see if I get any noise. I wasn't getting any with the tail strobe, but then the wires aren't in as close a proximity to each other.
Here is the left wing root area. Nearly ready to mate the wing for good.
And the right wing root.
Once we got the wires threaded through (which was very easy thanks to the tubing/conduit), we started the process of mating the wings. Steve got the outboard end with a little help from a short sawhorse. We worked the wings into place and Steve pulled the cables through as the wings slid in. I got the bolts started with the hardware store tapered ones we had for getting the holes lined up. Then I oiled up the NAS close tolerance bolts and pushed them in (with a mallet) to place.
I fitted the rear spar bolt too on each wing. Right now as you see it, the wings aren't torqued up. The bolts are just in place. I'll torque them up next time I'm at the hangar. There's a few things to do to finish up the wings being on for good, but this is it. They ain't coming off again!
Here she is. Wings on. A very satisfying moment. It really is starting to look like a plane now. Fantastic. Thanks for your help Steve!
2/14/2006 2 Hours
I tried to spend some time at the hangar this evening, but only managed two hours. Trouble is, the hangar isn't on my way home from work anymore, so it's a lot harder to get time in in the evenings. It takes me an hour to get home, then 20 mins to get to the hangar. By the time I get there it's 7pm. Then I need to get home to bed early otherwise I can't drag my lazy arse out of bed in the morning!
So, all I got done this evening was the flap pushrods. Better than nothing I guess. I cleaned araound a bit too and picked up the assorted hardware that was lying around in various places and sorted it out into it's relevant containers.
Here's the flaps in the down position.
Here's a shot from under the plane so you can see the pushrod. I need to order some locking nuts for these. Now that I'm getting a lot of stuff together, I'm wondering where all my hardware has gone?!
2/19/2006 8 Hours
I was tempted not to go to the hangar today as it was so cold. I didn't get there until noon, hoping for the temps to go up a bit. By the time I got there, it was 18F. Freezing!
I spent some time today rigging the ailerons, and setting up the autopilot servo pushrod. This took a fair bit of time. Basically, the way I did it was to pull the flaps up fully to the fuselage, then align the ailerons with the flaps and clamp them together. I then took the aileron bellcrank jig from Van's and adjusted the aileron pushrods until the bellcrank was in the correct neutral position. Next, I set up the sticks to be vertical, and adjusted the big pushrods to the correct lengths. Once this was all done, I tightened everything up to spec. Sweet. I did run into an issue with the left bellcrank. For some reason, it seemed to be binding, which meant the controls weren't smooth. I'd had this issue before with this bellcrank, and I thought I'd fixed it. I guess not. So, off it came again. I ended up running a drill of the exact size through it to clean it up. It was a lettered size, but I can't remember which size it was. The bushing was a little galled up too in the areas where the bellcrank flanges are welded to the tube, so I suspected that the welding had caused the tube diameter to decrease locally. I cleaned the bushing up with some emery in the drill press, and all's fine again now.
The next job I did was install the AOA ports into the wing. On the RV-7, the upper port should be 4 3/4" inboard from the outer edge of the wing skin, and 6" forward of the wingskin edge at the spar. The upper port should be the same forward, but 7 1/2" inboard. I didn't drill the hole for poking the upper port to clear any water that may have accumulated yet.
Here's the lower port. I had to mix up some more of that dreadful proseal.
And the upper port. Same deal. Proseal yuk.
Here's the upper port from the outside. It's a bit blurry! The hole is tiny. I was worried about bending or snapping the drill! In order to get the screws to sit nice and flush, I drilled the holes with a #40, dimpled them, and then ran a countersink cutter into them a little until the screws were flush. A #40 dimple just isn't quite deep enough.
The lower port. A little better focused.
Tank brackets. I match drilled the aluminium part of this set up on both tanks, and opened the holes up to 1/4". I then put the 'shorty' nutplates on. I sandblasted the rust off the brackets outside (yep, I damn near froze my ass off!) and came into the warm to paint them. I like the sandblaster. It leaves a great roughed up surface for painting. Once the paint was dry, I assembled it all. The plans say not to overtighten this bolt, and to stop tightening when the washer stops turning. Well, my washer didn't turn to start with, so how I'm supposed to know how tight is right is beyond me! Van's, I think we need a torque call out for this bolt! I still need to safety wire it too, so I need to look at a couple of other builder's sites to see how they did it. Blatant copying eh?! Hmmm.
You may also notice in the image below that the fuel line has disappeared. As it turned out, my fuel line coming out of the fuselage was perfectly lined up with the tank outlet, so I had no need to put the elbow on there. I thought my outlet was further forward, but I was mistaken. I cut the tube inside the fuselage, and I'll use a union to make the tube a two piece affair. This will also help to get it all assembled a bit more easily too. It was a pain before coz of all the bends in it.
After getting the tank attachments done, I moved to the rear spars. This was a simple affair of torquing the nut down and putting a cotter pin in there. Something I was wondering about was why Van's specifies this long of a bolt, and three washers? Why not just use a shorter one and one washer?
Here is the pitot tube transition from aluminium tube to polyflow tube. I wrapped this one up while I was lying on the floor under the plane. I think now I'm ready for a pitot/static test.
Something else I did while lying under there was fit the stainless screws that hold the fuselage skin to the wings. Generally, today was a day of tidying up loose ends. The AOA tubes are all connected to the ports now too.
Back from vacation, it's been a while since I saw the plane! Something cool to do today would be to put in the landing and taxi lights. Today was a lovely warm day. It got up to 64 degrees F, which is pretty nice for Michigan in March! Unfortunately, there is a down side. The floor in the hangar is epoxy, and when it's been cold for a while, the floor is freezing cold, and the warm air of spring arrives. Guess what happens... Tons of water condenses on the floor, and I have a mini flood on my hands. So today, I spent a good time squeegeeing out the water. Took out a chunk of aeroplane time.
Anyway, I dug out the template for the light holes in the leading edges, and stuck them to the wings. I marked the shape on each wing, and then started cutting with the cut off wheel. This was quite nerve wracking, as these are perfectly good wings ate the moment, and I don't want to slip!
The duckworks instructins have you mount the ballast on the light retainer. I decided it'd be better on the wingtip. I just didn't want to see screw heads through the wing lens. Hopefully, it won't be too noisey for the nav antenna, although, you don't really use these lights away from the airport much.
It works! It's pretty bright too! I need to paint all these parts grey before I put them inside the wing. It started to turn colder again, so I didn't get chance to do the plexi glass lenses. I don't want to risk cracking them, so I'll just be patient and wait.
