Baggage Door - EAA Tech Counselor Visit #3

One step closer to finishing the baggage door! Tonight I fabricated and installed a stiffening plate across the baggage door frame where I had cut it to fit the latch. I'm pleased to say it added the exact stiffness I was hoping it would, and now the only thing left to do is find and install a mini strut to hold the door open and prevent it from opening too far.

The stiffening plate connecting the two halves of the baggage door

As for the strut, I believe I've found the correct part for that from McMaster-Carr, P/N 9417K6, a "Miniature Gas Spring" with travel from 5.55" - 9.05" and 20lb force (edit- see later post here, recommend 5lb force instead), combined with P/N 9417K92, the accompanying mount bracket (edit- this bracket is too big and bulky, just make your own out of aluminum angle). The parts are on their way, and I'm hoping they work out nicely. After that is installed, we're just a few blind rivets away from calling the baggage door 100% complete!

In other news, our EAA Tech Counselor came by tonight for a visit to see the project. This is technically his third time here in the shop, but the first time was before we even set our first rivet on the empennage kit, just to look over our shop and tools, and to make sure we were on the right track. The second visit was after we had completed the elevators but hadn't yet started on the tailcone. Unfortunately, during those previous visits we never completed any official EAA paperwork to document the inspections (other than logging it ourselves). No big deal but in hindsight it would have been nice to have done it just to cross t's and dot i's. This time, though, we got our yellow slip:

EAA Tech Counselor Notes

He did an extremely thorough job inspecting the wings and fuselage, and I'm happy to say that overall he had some very positive feedback for us. He even noted "excellent workmanship overall" in the comments.... wahoo! Talk about how to brighten someone's day. It felt incredibly rewarding to have an expert in E-AB aircraft (and an RV-6 builder/owner himself) look over our work and give it the thumbs-up. The only thing he noticed was on the aileron torque tubes, the nuts holding the tubes to the bearings didn't have enough thread showing. The FAA rule is that there must be at least 2 threads showing beyond the nut, and on our wings that didn't work out to be the case:

The aileron torque tubes with AN365 locknut and washer, and only ~1 thread sticking out the top

I was already aware of the "2-thread" rule, but admittedly I guess I thought it was more of a guideline and not a hard-fast rule. Also, I thought I had the hardware installed per the plans, so "it must be right." Plus, the way the whole tube is in there, there's no way it's coming out even if the nut were to fall of entirely somehow. So at first it seemed like kind of a trivial finding, but since it's an FAA rule and will surely be looked at by the DAR when they come to inspect the plane for airworthiness, this could end up costing us a fair amount of time (likely several weeks) if they ding us for it and make us fix it, then we'd have to perform the fix and reschedule a time for another inspection. Way better to remedy this now!

So how did this happen in the first place? Well, we got out the plans for the wing and turned to Section 23 (aileron actuation) and reviewed the hardware callouts. Guess what? We goofed. They call for an AN364 (which is a low-profile version of the more common AN365) locknut to be installed in this location... oops!

The hardware callouts in the plans, Section 23-7, Figure 1

Simple oversight on my part in the callouts. Definitely a good catch, and lesson learned! I'll have to dig up the correct hardware (couldn't find any AN364 nuts in my hardware bins) and swap them into place, should be a very straightforward fix.

Other than that one finding, everything else went very well during the inspection! We then spent a long time discussing all kinds of things from avionics to flight characteristics, and all the different aircraft he's seen over the years. I can't possibly stress how thankful I am that a program like EAA's Tech Counselor program exists, and even more so for the individual counselors who volunteer their time to help others like us get through their build in a correct and safe manner. Thanks Tom! :-)

Aileron Actuation - Fuse Bottom Skins

Got another "to-do" checked off on the wing section today... yay! Finished the Aileron Actuation section today, which was a pretty cool section to work on. Previously, we had already created a few pushrods and bellcranks but not the torque tube assemblies, so it was time to get started on that:

Clocking/assembling the aileron torque tube assemblies - 5/16" offset and 17-3/4" total length (+1/32" acceptable)

One of the brackets needs to have a 5/16" clocking with respect to the other, as written in the plans. I decided to use a 5/16" drill bit (shown above) as my reference for clocking since it has a very precise "known" size. It went pretty smoothly and before I knew it I had two mirror-image torque tube assemblies. Now to prime and install on the wings. Installing them between the two torque tube bearings was actually was trickier than I thought it would be; there really isn't much room to work the pieces around, and the fact that the pieces have now been primed means they are even more reluctant to slip into one another. Eventually though, I prevailed and ended up with these torque tube assemblies installed:

R Aileron Torque Tube assembly

L Aileron Torque Tube assembly

With these installed, it was time to put the rest of the works together! This was exciting, because when complete you can push/pull on the levers here on the torque tube, and see the ailerons go up and down, way over on the other side of the wing... like magic! So, a few bolts/nuts/washers later, I had the following assembly together:

Torque tube -to- pushrod joint

Aileron bellcrank assembly with two pushrods

By golly it works! Awesome. Played with the ailerons, moving them back and forth for a longer period of time than someone my age ought to have. Oh well, no one was watching. We'll still need to final-rig these bearings at a later time for all the correct tolerances once everything is together, but they certainly appear close to the recommended clockings and everything moves smoothly and precisely! Very cool, couldn't be happier.

After Sarah got back from her afternoon plans (which included tearing up the skies over Marion in a C150, I might add), we got back to back-riveting the fuselage bottom skins. It's a fun process but gets pretty tedious after a few hundred rivets. We persevered through it all though, and I'm pleased to say that all back-rivetable rivets are now back-riveted! There's still a few dozen here and there that we skipped over to get later via the traditional flush-riveting method. Maybe tomorrow we'll get to that. No pics of the fuse in its current state yet, we're saving the "reveal" for when we get those last rivets done... hopefully tomorrow!

Flaps - Ailerons Complete!

Happy Memorial Day! Today was a work holiday for me, but unfortunately Sarah had to go to work at the airport. So, in an unprecedented and incredibly bold move, I decided to break out the proseal myself and do a round of it solo. All things considered, it actually went pretty well, and somehow I didn't make a giant mess. Sarah would be proud.

I started the solo proseal adventure by gooping up both flap trailing edges and clecoing the assemblies together. I had just enough remaining to attempt to patch up the part of the L fuel tank that appears to be the only place that had a leak. We'll have to let all this cure and retest.

Next, it was time to rivet the aileron trailing edges together, that had been setting up since Saturday. That also went pretty uneventfully, and in short order both ailerons were complete! Yay, something we can check off the "partially complete" list as now "done"!

Not much else to report today, and tomorrow we'll be going to a fly-in BBQ at KIIB. Hoping to get the flaps and fuel tanks completely done sometime this week, then it's on to the fuselage!

Aileron Actuation

Since we're simultaneously working on a few sections, why not start on yet another? Can't think of one good reason! :-)

While we're waiting for proseal to cure, we skipped ahead to section 23 to start on the aileron actuation section. This part of the plans involves constructing a series of pushrods, bellcranks, bearings and torque tubes that will translate pilot input to movement of the ailerons.

No pictures today either (I think we're getting lazy with the camera... need to change that) but basically we got through page 23-4 step 2, which means the four pushrods have been fabricated, as well as the outboard bellcrank installed. Still need to build the forward and aft torque tube assemblies, and clock everything together. We'll work this in as time permits, no huge rush on completing this section either.

That's about it for today, it was a relatively short day in the shop! Tomorrow if we're feeling crazy we might try and knock out the flap trailing edges and bottom skins, and see about patching the one small leak in the L tank.

Flaps - Ailerons - Fuel Tanks

Things are getting pretty hectic in the factory over this long weekend. I feel like we're simultaneously working on 3 or 4 sections at the same time, and all of them are only "half" done. We're halfway through the wing bottom skins but on hold to go any further until we're ready to seal up the wing, we're halfway through with the flaps, we're mostly through the ailerons (except trailing edge), we're mostly done with the tanks but still need to pressure test them... time to move some of these to "complete" status!

Not today, unfortunately. However, we did make leaps and bounds of progress towards this goal. Started this morning with riveting the L and R flap leading edge and top skins to the skeletons. We again installed the flaps onto the wings to check for straightness. They are much more rigid now but can still be influenced one way or the other, albeit only slightly. Still looking straight, which is great news! Then we took them back off the wings and started installing the bottom skins. The flaps are now to the same point as both ailerons: Complete except for trailing edge, and perhaps a few blind rivets that need to wait until the trailing edge is assembled.

With talk of the trailing edges comes talk of Proseal. With talk of Proseal, of course, comes talk of our fuel tanks, namely the goof-up we did with the R tank attach zees being all backwards. So, with the sealant all fully cured it was time to bust out the drill and attempt to carefully remove the seven zees and extract all the rivet tails from the tank. Surprisingly, drilling them out was quite easy (finally, something seemed to go right)! I was also able to fish out about 2/3 of the rivet tails with little issue. The rest of them are still floating around in there for now, but I think the best bet is to try to rinse them out once the tank is sealed up again. We'll keep count, and make sure we get them all.

With the R tank zees removed, cleaned up, and oriented properly, we mixed up a batch of proseal to do the aileron trailing edges and re-attach the zees in the correct order. Happy to say that both efforts seemed to go quite well, and now all that's left to do proseal-wise is the flap trailing edges.

Last thing for the day, it was the "moment of truth" for the L fuel tank. I had bought some fittings, tubing, and valves a week or so ago to make a pressure testing system to connect to my compressed air supply and pressurize the tanks to around ~1psi. This is a higher pressure than what the proposed balloon method allows, which I've read only pressurizes to around 0.5psi. That comes up a little shy of nominal tank pressures during flight when filled with fuel, so I decided to go with this method.

The results were good overall, I'd say. The tank initially held the 1psi pressure, but over the next 10 minutes I noticed it was definitely dropping slightly. A soapwater spray of the tank's exterior quickly revealed the apparent only leak-- at the outboard-top corner where the end baffle meets the aft baffle. Van's points this area out as a common leak source (all four corners, actually), but this particular corner is a sort of "best case" scenario for leaks, as it is the top-most part of the entire tank and theoretically needs to be the least leakproof, so to speak. From the looks of it, we should just be able to goop a bit more proseal on that corner and it should resolve the issue. We'll see if it's that simple... fingers crossed!

Now we wait for some proseal to cure... maybe tomorrow we'll get started on Section 23 - Aileron Actuation! That would be cool, because it's the last chapter of the wing kit! (Except tips, which we're putting off for now...)

Stay tuned!

Ailerons

Finished the ailerons tonight! Well, except for prosealing and riveting the trailing edges, which I think we'll probably do as a batch job with the flaps and the R fuel tank. Oh yeah, the R fuel tank. Guess what I just discovered we did while I was standing here admiring our work on the tanks?

One of these things is not like the other one

While assembling the baffle for the R tank, I laid out all the attach zees in the correct order and orientation to start from the *outboard* side and not the *inboard* side. So the result? They are all backwards (the L tank pictured on the left above is correct). Grrrrrrr. That was an embarrassingly dumb mistake, and I get to take full credit for it. While we were originally putting these together, Sarah had relinquished her responsibility for the orientation of these parts because she didn't want to mess them up, and trusted in me to get it right. That will teach her...

I guess it's not the biggest deal in the world, things could be way worse. Looking through the forums I found more than one case of a builder doing the exact same thing. It's just going to be a time consuming, frustrating, and tedious ordeal to drill out all of the Zee rivets (12 solid rivets along the exterior flanges and 30 blind rivets for the interior), fish out all 30 of the blind rivet ends, regroup, and re-rivet them into place in the correct order. The hardest part is going to be to ensure we recover all 30 rivet ends. I think this is doable as long as we first wait for the proseal to cure, and take our time getting each piece to come out through the fuel fill opening.

Anyway, that was basically the only real excitement tonight, if you can call it that. Otherwise the ailerons are basically done, and we're ready to begin work on the flaps! We've got a number of plans, mostly related to flying over the next couple of days, so we may not get much more work in until the weekend. Oh yeah, and the fuselage kit should arrive at some point this week!

Ailerons

The past few days have been filled with an array of other plans including hanging out with some friends we hadn't seen in a while, and then going to the Quad Cities airshow on Saturday, where we both somehow got burnt to a crisp under an overcast sky. Saw the Blue Angels for the first time ever, which was really exciting... what a show! That, along with walking the flight line and talking to everyone from the V-22 flight crew to a guy who restored his own DC-3, put us both in the mood for building!

Happy Mother's Day! Made a lot of great progress on the ailerons today. Final-assembled the counterweight and nose rib assembly, and placed them into the leading edge skin for more drilling, this time to make holes in the counterweight for the leading edge itself.

The right outboard nose rib, with counterweight attached

A close-up of the right inboard nose rib, with counterweight attached

The assembly is placed into the leading edge skin so the counterweight can be drilled to make holes for the leading edge blind rivets

After the leading edge assemblies were complete, we deburred, dimpled, and primed the four aileron skins, and then back-riveted the 32 stiffeners to them.

The four aileron skins with 8 stiffeners and 2 end brackets each

Back-riveting a flat and relatively small piece such as an aileron skin is quite easy and stress-free, compared to a lot of the messy work we're used to getting into with the tanks! It was a very welcome change. Anyway once the skins were completed, it was time to assemble the whole thing for drilling the spar and trailing edge. This is very similar to the construction of the elevators and rudder (essentially the exact same process), so I laid out some scrap pieces of wood (for drilling into), ensured everything was straight, square and level, and put the skins and trailing edges together. After a bit of drilling, we ended up with this:

Starting to look like an aileron!

After final-drilling the trailing edge, the assembly came back apart for more deburring, dimpling, and priming. The plans call to dimple the spar, which seemed odd to me (it's 0.040" thick) but we went with it anyway. It's quite a workout on the hands using the squeezer on material that thick, but we got through it all. Next, the leading edge had to be dimpled. Most of the holes could be gotten with the squeezer, but the few that couldn't be reached are a bit tricky to reach. Thankfully, the MikeyJ-2000 dimpler didn't disappoint!

Not a very good shot, I couldn't hold the part straight and hold the camera

Anyway, with the skins dimpled (and primed), it was time to begin final assembly. We cut out and screwed together 6 cradles per the plans to hold the leading edges of the ailerons (and flaps later) during assembly and got to work. First part was to assemble the leading edge. We placed the leading edges into the cradles and clecoed the ribs and counterweight assembly together like this:

Right inboard side of aileron leading edge

Right outboard side of aileron leading edge

It's a pretty tight space in there, especially if you have big hands like me, but it is doable. Without question, the tungsten bucking bar is critical here. Honestly I'm not sure how you'd do it without one. From here through the rest of the day, I just focused on the right aileron. I riveted the nose ribs and counterweight assembly to the skins, and realized I was running low on LP4-3 rivets. I think possibly because I used them when installing the wing leading edges in places where Van's gave you a choice between blind or solid rivets, I'm going to be about 15-20 rivets short I think. I'll have to place an order for some more first thing Monday.

Anyway, after riveting the aileron leading edge together, the spar and top skin could be installed. We clecoed it into place and started riveting it together, from the middle out towards each side. There was plenty of room to work with because the bottom skin still hadn't been installed, so that was going to be the hard part.

The completed R aileron top skin, from the inside

Close-up view of the inside of the R aileron with top skin installed

In order to orient the bucking bar properly, a "bump" had to be created out of some rolled-up duct tape so that it would sit level with the spar flanges.

Now comes the hard part: installing the bottom skins. There isn't a whole lot of room between the skins, and somehow you've gotta get your hand down in there to hold the bucking bar in place to set all the rivets along the spar. I slid the bottom skin into place, and got to work.

There is just enough room to get your hand in there and enough fingertips on the bucking bar to hold it straight while riveting. This photo was taken directly in-line with the bottom skin (you bascially can't see it) and you can see one AN426AD3-3.5 rivet put into the hole, ready to be set.

Got about halfway through the line of rivets... it's slow going but actually isn't all that bad. We shouldn't have any trouble finishing this up tomorrow and hopefully getting most of the way through the left aileron too... then, on to the flaps!!

The race against the ABF truck carrying our fuselage crate continues... who will win??!? :-)

Ailerons

We had originally planned to fly to KPDC today with some friends to grab a steak dinner (because why not?) but the weather wasn't playing nice with us. I think we could have made it there in a pinch but it's not quite as glamorous or fun when you're up there dodging thunderstorms and dealing with bumpy air and gusty winds. So... into the airplane factory we went for a short day today doing some pretty repetitive work... we finished drilling and deburring the counterweight assemblies for both the R and L sides, which involved clecoing the leading edge skin to the spar and nose ribs. Kind of a cool-looking little piece:

Other than that though, I jumped in to help Sarah with the 32 small stiffeners she had cut out from the provided aluminum angle strips. She finished filing/deburring the edges while I final-drilled, deburred, and dimpled the 224 holes (7 per stiffener). Next step I believe is to do the same thing to the four aileron skins and the spars; and then do another round of priming. Then, basically all that's left is to assemble it all! Should only be a couple more days left on the ailerons, at most, I think. Problem is, our schedule is filling up these next couple days so I'm not sure if we'll get much building in until maybe Sunday. We'll see...

Ailerons

Continued working on the ailerons tonight. Drilled, deburred, dimpled, scuffed and primed the nose ribs, hinge brackets and end ribs, as well as riveting each subassembly together. Meanwhile, Sarah got to work on cutting out the 32 stiffeners from their aluminum angle strips. I have to say, things are going so much faster now that we don't have to deal with proseal anymore! It's definitely a welcome change.

One thing to note with the RV-10 aileron plans: our kit shipped with "Revision: 1" ailerons, which is annotated in the bottom right corner of the aileron pages. These plans (and the parts that come with them) appear to be significantly different than the "Revision: 0" plans contained on the CD-ROM we bought containing PDF's of the plans. For sure, the main ribs and hinge bracket design is completely different, and it appears to use the same part numbers too, making things even more confusing. Furthermore, these Revision 1 plans are clearly written by a different author, and so slightly different methods and descriptions are presented for similar tasks you may have gotten used to being described in another way. Lastly, it seems that so far, all the holes are already punched out to the proper size-- no final-drilling has actually been necessary! Everything is already #40, #30, #12, or whatever size they are supposed to be. Weird.

Anyway, we got to the point where all the little nose and end ribs had their brackets riveted together, and called it a night. I'll be sure to take pics next time, there really wasn't much different tonight than in yesterday's pics except everything is primed.

Excited to be past the tanks... feels like the end of the wing kit is approaching!

Fuel Tanks - Proseal bottle #7

Finished the tanks tonight! Well... for now anyway. We'll still need to test them and repair any leaks, as well as finish priming and installing the bearings and a few nutplates that we've deferred for now. For all intents and purposes, the tanks are "done".... wooooo!!! That was one of the longer and more painful endeavors so far.

Today after work we mixed up our seventh and final bottle of proseal and installed the baffle for the R tank, in a duplicated effort from yesterday when we did the same thing to the L tank. I have to say it went quite well and didn't take too much time, maybe an hour and a half or so for the entire job, which included about 200 flush rivets on the top and bottom aft flanges and 40 pop rivets to hold the attach zees and baffle to the tank flanges.

With that, it was time to set the tanks aside to let them cure for I'm thinking at least two weeks. That should give us about the perfect amount of time to build the ailerons and flaps, and get them attached to the wings before the fuselage kit arrives. Speaking of which, this is "the week" Van's says the kit will ship, so I can tentatively plan to see the crate here by maybe next week sometime? We're very excited to see it arrive!

Since we got done with the R tank so quickly, we had just a bit of time left to clean up and pull the parts for the ailerons. After some cellophane-peeling and parts-labelling, we had a surprisingly small stack of parts that need to be cut, filed, drilled, deburred, dimpled and riveted together! I snuck in a few minutes in with the bandsaw to separate the A-1005, A-1006, A-1007, and A-1008 bits (pictured below) but other than that didn't do any real "work" on anything. Still plenty more cutting, sanding and filing left to do!

The A-1005 thru A-1008 bits that make up the guts of the ailerons

Aileron skins, spars, stiffeners, and counterbalance

We're hoping that after coming off a big project like the fuel tanks, we should be able to make quick work of these, followed by the flaps which appear to be a fairly similar process, only slightly bigger of course. One thing we'll need to keep in mind is that it is critical to keep these parts straight and square when final-drilling and assembling them... apparently a number of builders have accidentally put a "twist" into them which carries through to the final product. I have read that unless the twist is extreme, it doesn't affect flight characteristics much (it can usually be trimmed out) but it is a definite cosmetic issue. Also, of course I'd rather not build a twisted *anything*. We'll see how well we can do it!