Dimpled Right Fuel Tank

Today the only work we were able to really do was dimpling the right fuel tank. We used our normal method of back dimpling and while we were doing this I remembered that there are special dimple dies out there specifically for the fuel tank skins. Why? Well the fuel tank dimple dies put a deeper dimple in the skin to allow more room for the tank sealant. We spoke with our friends Jack and Dwayne to see what they thought. They suggested that since we had already dimpled a whole fuel tank skin that we take our deburring tool to take a bit of material out of each dimple. This would allow enough room for the tank sealant and for the rivet to sit flush. After a bit of trial and error using slow electric screw drivers and countersink bits, we ended up using the deburr bit in its handle. A few quick twirls took enough material out to let the rivet sit deep enough. We've realized that this is a common (not mistake or error, but phenomenon?) with many RV's out there, if it isn't dealt with, you are left with rivet heads that don't sit flush and are high enough for you to feel with a finger nail. Not the biggest deal, but we want our wings to be smooth so we'll be putting in the extra effort up front!

Inboard Fuel Tank Ribs

After breakfast at the cafe today Dad and I had to take care of a couple of errands but once they were done we headed over to Smitty's to pick up some of the two part epoxy primer so we could start getting some more parts primed! Though today's weather wasn't quite good enough to use it.

Dad and I began working on the inboard fuel tank ribs to get the ball rolling with them again. We started by cutting the access hole in the rib with the flycutter. This was my first time using this tool. Like everyone says, make sure you have the part you're cutting clamped down extremely good. This thing could take a part and throw it accross the room in a second I'm sure. We changed the belt on the drill press for this and set it to the lowest setting, this helped a bit with controlling this beast. After the ribs were cut we clamped the access plates to them and match drilled the holes. Once the plate is drilled the ring goes on next and the platenut holes get match drilled. We realized that there was a bit of rib left inside the ring on each so Dad cleaned them up with the Dremel and got them perfectly equal with the ring. We deburred everything and decided to call it a day, it looks like we'll just have to wait for some nice weather so we can get some priming done! Until then we're in limbo.

Flap Skin Preparation

Well today before work I tried to get as much done on the flaps as possible. Yesterday Dad and I had already started dimpling the skins and the skeleton for the flaps, so today I decided to get these things all knocked out.
I was able to get all of the ribs and spars scotchbrited (if that's a word) and finished deburring all of the holes. Once this was done the dimpling continued. I finished all of the edges with the hand squeezer and picked up were Dad left off on back dimpling the skins. All in all it was a productive day for the time I had, and therefore I'm happy!

Busy Day!

Today Dad and I were able to get a lot done today on the project. Since we've reached a bit of a hiatus with the wing we decided to continue on the flaps. I've been working alone a bit on the flaps the past couple of days but today we were really able to slam some work out. We started by drilling the skeleton to the bottom skin and drilling the hinge for the right flap. When we first tried drilling the hinge a couple months ago we really overthought it and decided to let it sit for a while. But today we just dove in and finished that task. They look good! When it comes time for attaching the flaps to the wings we're going to split the hinge pin in half and bend a 90 in each which will then attach to the flap brace, making it easier to remove later on.







Another project for the day was to fabricate the FL-706A brackets and to bend the FL-706B brackets. The 706A's are made from 125 x 1 1/2 x 2 aluminum angle and they support the inboard section of the flap where the linkage connects. A couple of passes on our band saw and a few swipes on the deburring wheel and they were ready to be drilled. I started by clamping the 706A to the flap spar and match drilling it. Once this was done, it got clecoed (while being drilled) to the spar. The next step was to put a 6.3 degree bend in each 706B, one will be bent up and one will be bent down (right and left). After trying a bending brake and failing I headed over to our friends hangar to seek help. He suggested a vice and together we decided to use a 1/4 drill bit and a set in the vice to put the bend in the piece. After a bit of trial and error, we were able to get them lookin' perfect. I took these back to the hangar and clamped one to the flap spar and clecoed it to the inboard rib, once this was done it got drilled. After everything is drilled, the aft most hole (not the tooling hole) gets enlarged to 1/4" for the bolt that connects to the rod end bearing. Once all together it feels really strong!

Dad was able to get the skins all devinyled and once this was done we deburred all of the holes, inside and out and dimpled some of the skins. These flaps are really close to being primed and riveted together. Thursday we should be able to pick up some more primer from Smitty's eventhough the forecast for the week looks crummy for painting.

Countersinking Fuel Tank Skins

Continuing from the past couple of days, we picked up on the right fuel tank. I had the T-405 angle all drawn up from Monday and just had to cut it out. With a few swipes on the band saw and about fifteen minutes on the bench grinder we had our second one done! To get the hole pattern on the second one I just clamped them together (they mirror eachother) and match drilled it. Once we had both of our brackets ready, we clamped them to the inboard ribs of the fuel tank and match drilled them. We made sure to leave a bit of room between the angle and the skin since there will be rivets being set right there. It looks like enough room for a shop head, but if we need to we'll just put a few notches in the angle once the rivets are set. After the rib itself was drilled, we clamped on the T-410 plate and match drilled this, yes we match drilled a lot, but it provides the best results!

The plans call for the fuel tank skin to be countersunk where the baffle attaches to it. We weren't sure if we were reading this right because skins are normally dimpled since they're so thin. This skin was .032" so it wasn't as thin as others, but we still decided to research this a bit more. We found out that this was correct and the reason for this is to make it easier to fit the baffle in upon final completion. It has to slide into place and if it were dimpled it would make it more difficult get into position. I'm guessing they want these steps to be as quick as possible since you're using Tank Sealer.

While I did the countersinking Dad finished devinyling all of the rivet lines on the skins for the tanks and they are now ready to be dimpled. Towards the end of the working day I got acquainted with the capacative fuel senders. I finally have an understanding on how they work and they seem pretty simple. At least there's not going to be any moving parts in our tank! Except for maybe a flop tube, and trapdoor..

Tomorrow after work I hope to continue on the capacative senders and get the tanks ready to be sealed! Eventhough we have the tanks ready for the most part I feel it'll be a little while before we're ready to start the sealing process, which I hear takes a few days to do correctly.

And yes, I cut my hair. FEELS GOOD.

Right Fuel Tank

Well these past few days Dad and I have been continuing our work on the fuel tanks. Once the left tank was mostly done, (still have to countersink the skin where the baffle attaches) we started the right tank and now both are at the same stage. We've just been forgetting the camera! Tomorrow we should be able to get the tanks ready for the capacative senders!

More Fuel Tank Work

Another productive day today! As always the day started out at the cafe to have some breakfast and load up on coffee. We met our friends there and after breakfast decided to head over to their hangars. After a few minutes of talking with our friend Dick he offered to take me up in his RV-6. I couldn't say yes fast enough! What luck, he let me taxi, takeoff, maneuver, and land! After we took off we head out to do a few maneuvers and turned back to practice some touch and goes. After him doing the first one he let me in on the techniques he uses for slowing down and what airspeed to aim for on final. The first few weren't exactly perfect but they were suvivable. My fifth and final landing was almost a greaser! All three wheels down at the same time; if that's not motivation to continue the build I don't know what is! What a great ride, and it was only my second RV flight to date. Got to log that one.

After the ride it was time to get back to the real world. Dad and I headed over to the hangar and got to work! The fuel tank skin was still clecoed to the spar from yesterday so we continued from there. If the skin doesn't match up perfectly with the spar/baffle/leading edge, then you're supposed to elongate the holes that you previously drilled through on the baffle. Ours however came out perfect! Just a couple of holes had to be re-drilled to make the baffle fit a bit easier to the brackets. The plans call for the ribs to be clecoed to the Z-brackets and the baffle, then match drilled. After using the long #30 drill bit to get these done we headed out to lunch.

We took off the ribs and clecoed them to the skin. Man the tank looks (and feels) awesome with the ribs in it. Once they were in the assembly goes back onto the spar to be drilled to the W-423 joint plate. We did this and decided to drill all of the holes in the skin (this was where we made a mistake). The plans say to only drill the joint plate while the tank is on, this way you don't accidently drill into the spar. Well dummy me missed that part of the plans. After we pulled the tank off we noticed we nicked the spar a bit with the drill. About five nicks got put into it that will need to be sanded/buffed out. They're not critical, but we don't want anything that can develop into a crack on our spar! I sanded them down a bit and they're already pretty rounded off, but I still need to get them perfected out.

With the tank off we finish-drilled the tank attach holes with a #19 drill for the attach screws. This thing is looking awesome! While I'm at work tomorrow Dad's gonna head over to the hangar and start devinyling some skins and dimpling a few parts. After work I plan on countersinking the tank skin for the rivets that attach the skin to the baffle. We're making progress slowly but surely!