Wings

First thoughts: Everything from the empennage seems tiny after touching all the wing parts.  From 10-foot main spars to fiberglass wing tips that a small child could use as a canoe, the scale has definitely bumped up quite a bit.

Even though my delivery was scheduled for the afternoon, I got a call from the driver not too long after 11 AM, asking if it was possible to do the delivery earlier.  Since I work close to home, I agreed.  I’d been planning on stopping by Lowe’s to get a furniture dolly to help with moving the crates, so the only wrinkle in the accelerated delivery was that now I had to really move to get the dolly and get home to meet the driver.  He actually beat me to the house; when I got there, he already had the larger of the two crates partway onto the lift gate.

I had a couple friends heading over to help out, but meanwhile the driver and I kept going on the first crate.  We moved it back and I stabilized one end while he lowered the liftgate with the other end.  We got it onto the dolly and rolled it down the driveway and into the garage.  I’d kind of been worried about the muscle needed to move the crates, but doing it with two people and the dolly was easy.  I did, however, notice when it came time to get the crate off the dolly that it was upside-down, so we carefully rolled it upright.

As we headed back out to the truck, my friend Rich showed up, the first of my two requested helpers.  Actually kind of good timing, since crate #2 was the 16′ long spar/longeron container.  An extra set of hands was helpful for getting that one down and onto the dolly, after which Rich and I rolled it into the garage.  About the time we got that crate off the dolly, Cristian (aka Friend #2) arrived, just in time to sort of stand back and say, “Yup, looks like some airplane parts.”  After writing a check for the freight charges, it was time to grab some lunch and head back to work.  Surprisingly, I didn’t have a lot of trouble being productive the rest of the day…probably because I’m trying hard to wrap up a project, so I’ve got plenty to do.

Reception photos:

Back home that evening, I cracked open the crates and got to work inventorying.  Josie came out to help once she’d finished up her work day, and I found that having two people for inventory makes things go quite a bit faster.  Over the course of two hours, we checked off everything in the crates except for the Big Bag O’ Hardware; we’re going to leave that for tomorrow night, and take care of some hardware organization at the same time.  I also haven’t put away most of the parts; I did get the ribs stacked on one shelf, but everything else i left kind of out in the open, because I want to try to organize everything effectively instead of just tossing it on the shelves all willy-nilly.  And I’m not quite sure yet how to store the wing skins or the longerons and other extremely long parts…

Cracking the crates:

Spars!

Ginormous pile of packing paper:

Last night, I wrote that Josie and I had inventoried “everything…except for the Big Bag O’ Hardware.”  Whether it was evident or not, I was personally under some kind of impression that we’d gotten a large chunk of the inventorying done.  Boy, oh boy, was I ever wrong.  Yes, it took the two of us a solid four and a half hours to inventory and organize all the hardware.

In fairness, though, the actual inventorying didn’t take all that long…maybe an hour or so.  But I learned a lesson about organization with the empennage hardware.  When that kit came in, I did break out the various solid and blind rivets and put them in a little drawer unit I got from Lowes, but every other piece of hardware I left in the bags they came in.  For some things, like the rod ends and associated lock nuts, this was no problem.  For others, like the small assortment of nuts, bolts, and washers, it was a little more of a pain.  I did a lot of repetitive work…say I needed a particular washer, for example.  Usually that washer would be in a small plastic bag with one or two other washers, and half the time I’d have to dump out the entire contents and count the washers to figure out which one I needed.  Not exactly a recipe for efficient building.

I also grew displeased with that drawer unit.  I’d originally intended to mount it to the wall somewhere, but I never came up with a good place.  So I had it just sitting around, and it wasn’t exactly stable.  Plus, all the drawers were the same size, whereas I had widely varying quantities of rivets.  One drawer held exactly six of a particular blind rivet during its entire lifetime…quite a waste of space.  A few weeks back, when Daniel Schoning helped me with my bad elevator skeleton rivet, I noticed he had a nice storage setup for his rivets, a couple of tackle box-like units from Harbor Freight.  Each of the little bins is removable from the carrier, and the bins are assorted sizes so I can make better use of the storage space.

Anyway, to make a long story short, a lot of time went into sorting the hardware, printing out labels for the individual bins, getting everything arranged logically, etc.  We ended up with basically all of the semi-generic hardware (rivets, bolts, nuts, washers, platenuts, etc) in those two organizers.  Some of the bags that contained special hardware that was already grouped by purpose (aileron attach stuff, pitot hardware, etc) I left in those bags, though we labeled them more clearly as well.  So even though we put in a lot of time tonight – and I hurt in several places from sitting on the floor all night – I expect this to save a lot of time and headaches down the road.

I still have to get out in the garage and get the stuff out there put away in some kind of organized fashion…guess I’ll see about that tomorrow after work.

The aforementioned Big Bag O’ Hardware:

Rivets scattered all over the floor:

All of the solid rivets fit into one organizer:

All that hardware from that big bag, but now organized:

Well, I didn’t really get the good start on the wings I kind of wanted to today.  Truth be told, I slept in pretty hard…the last few weeks at work have been kind of stressful and draining, and I haven’t been sleeping that well, so it was nice to feel like I got caught up on some rest.  I finally found my way out into the garage early in the afternoon.

The first order of business was to get all the parts put away.  The crates were still out in the open where they were dropped Tuesday, and the place in general was cluttered.  I’d previously put the wingtips, along with the empennage tips, on the top shelf, and the wing ribs on another shelf, but everything else was scattered about.  I spent the next hour or so grouping parts by subassembly (flaps, ailerons, etc) and stacking them together on the shelves.  That was pretty simple…next I had all the long pieces to deal with.  The longerons are just under 16′ long, and there are also a couple of 12′ pieces of angle and tube.  Obviously those weren’t going on the shelf.  I ended up putting a couple of hooks in the rafters and hanging those long pieces up there.

That just left a bunch of skins to deal with.  After some thinking and general chin-scratching, I put all the control surface skins as well as the tank and leading edge skins on the shelf under the work bench.  Unfortunately, the main wing skins were too big to go under there.  After some more chin-scratching, I decided to hang them all on what was basically the only remaining clear wall space in the garage, using some small finishing nails through the rivet holes.  That should keep them out of the way until it’s time to get some skinning done.

The empty crates got put outside by the driveway for now.  I think I’ll cut them up for scrap/firewood, maybe tomorrow.

So now what?  The first task called out in the instructions is riveting the tank attach nutplates in place and countersinking for the attach screws.  Problem was, the metric ton of nutplates needed for this task are on backorder, which is a bit of an obstacle.  The next main spar tasks are installing the inspection cover nutplates and the tiedown hard points; however, I decided it made more sense to move on to the next major section of the plans, which is assembling the rear spars.  Actually, I just wanted an excuse to get some parts out and cleco them together so it looked like some kind of assembly.  Plus I could start getting some insight into how the wings go together.

I didn’t really get anything done on the rear spars besides clecoing the reinforcement forks in place.  Instead of just diving into work, I sat down with the instructions and started reading through them to get an overview of the whole process.  One thing that’s immediately obvious is that the step-by-step handholding from the empennage instructions is gone.  No more checkboxes beside individual steps; now I just get paragraphs of general instructions and things like “prepare the piece for riveting as usual.  Note that some holes will need flush rivets.”  It’s up to me to find out which holes those are, and to decide how to accommodate the flush rivets.  It definitely seems like there are a lot more opportunities to make mistakes, between the lack of handholding and the vastly increased complexity of the assemblies.

I was honestly a little intimidated and overwhelmed after reading through everything.  I’m going to have to work hard at getting my mindset right; if I think in terms of the entire wing assembly, it’ll always seem like I’m making no progress, so I need to focus on what current small piece I’m working on.  Eventually it’ll all come together.

I guess tomorrow I’ll get to work on those rear spars.

Got started out in the garage at an actual decent hour today, unlike yesterday.  It was a beautiful day outside, perfect for just opening the garage door and enjoying the perfect temperature.  I timed the arrival of the wings pretty well…just in time for spring!

The first order of business was to prepare the rear spar webs, the inboard reinforcement forks and plates, and the reinforcement plates for the aileron hinges.  The forks and plates are beefy pieces of aluminum stock, and the edges on them needs quite a bit of work; lots of tooling marks and bumps and such.  I probably spent a solid 45 minutes just on the edges of those pieces.  The insides of the forks presented a special challenge, since they’re not accessible with the bench grinder wheel.  I was able to get most of the length of those with a smaller scotchbrite wheel in the die grinder, but even that wheel was too large to get all the way into the fork.  For that part, I settled for working with various files and finishing things off with some emery cloth to get a good finish.

A look at the edge of a finished plate (top) and one that hasn’t been touched yet (bottom):

With all that edge finishing done, it’s time to drill the aileron hinge reinforcements to the spar.  For whatever reason, these don’t come predrilled at all, so they have to be clamped in place and drilled using the holes in the spar web as a guide.  For the outboard plate, alignment is easy; it just lines up with the end of the spar.  The inboard plate is located 50 3/4″ from the outboard end.  In order to be extra-careful here, I marked the rivet holes from the spar and removed the reinforcement to make sure edge distance was going to be OK before committing to drilling.

The drilling is pretty straightforward, but there’s another required modification to the inboard plates.  These plates cover a hole in the spar web that the aileron pushrods will pass through later, so a matching hole needs to be cut in the plates.  I traced the outline of the hole while I had the plate clecoed in place for drilling, then used a Unibit to make a nice-size starting hole in each plate, and then went to work with the Dremel and a cutting bit to finish the holes off.  I then cleaned the holes up using a round file and finished them off with emery cloth for a nice smooth finish.

Hole outline (the plate on the left is an outboard unit, which requires no more work):

Getting close, time to turn the Dremel down so I can control it better:

And the finished pushrod holes:

Next up, the reinforcement forks and plates are clecoed in place and final-drilled:

With all that done, I sat back in my deburring chair and went to work on all those holes I’d just drilled.  While doing this, I realized I’d forgotten some holes in the aileron reinforcements; since they nest into the spar channel flange, the reinforcement flange needs to be drilled there as well.  So I got to cleco them in place again, drill some more holes, and then deburr those holes.  FInally, I went ahead and dimpled the holes on the spar channel flange where it mated with the reinforcement plates.  I also dimpled the flange holes by the reinforcement fork; once the fork is riveted in place, these will be difficult to get to, so it’s better to take care of this now.

That got these pieces mostly ready for cleaning and priming.  I still need to dimple the flanges of the reinforcement plates and do some countersinking as well.  Particularly on the outboard plates, some of these holes need flush rivets; it’s up to me to figure out which ones and countersink or dimple those holes before assembly.  That will have to wait until tomorrow night; I was surprisingly tired by early evening, and I need to do some prep for work tomorrow…so I decided it was time to retire inside for the day.

I had really wanted to get the rear spar stuff primed today…so I was pretty disappointed when the forecast weekend rain turned out to be a miniature monsoon this morning.  I was kind of bummed, even though there’s plenty of other work to do.  But then the rain cleared up and it looked like I’d have the whole afternoon rain-free!  So when I went out to the garage, I stuck with Plan A and went to work on the rear spar components.

Everything was basically ready to go, except that I needed to dimple the flange portion of the spar reinforcements and countersink the outboard row of web holes.  Since those holes will be covered by the outboard aileron hinge bracket, they need to be flush.  The countersinking was mostly uneventful, except that one of the holes is pretty close to the flange, close enough that the countersink cage interferes.  So I fired up the bench grinder and “customized” the cage.  No problem.

Now it goes in tight spaces!

With the countersinking done, I proceeded to dimple the flanges of the reinforcements.  Things were a little tight to dimple with the hand squeezer, but I got it done, without problems…or so I thought.  On closer inspection, it turned out that I’d bent the flanges a bit on the reinforcements, such that they didn’t want to sit flush with the spar channel any more.  So I had to get out the hand seamers and bend the flanges back into place.  I really should go ahead and get an Avery vise-grip dimpler for tight jobs like this.

With that, I set about scuffing all the parts for priming.  I did the spar channels first, and wow…I was not prepared for the amount of work that took.  Up until now I’ve been mostly scuffing pretty small parts.  I went through two Scotchbrite pads just on the channels!  Once everything was scuffed and then cleaned thoroughly, I set them out to dry and took a break inside for a few.

Meanwhile, I needed some work to do in between shooting coats of primer.  If I move forward past doing the rear spar subassemblies, the next thing is to start cleaning up and straightening the ribs.  Or I could start looking at some of the main spar work.  Since I’d already been countersinking, I decided to stick with that and work on the main spar.  I’m still waiting on the backordered nutplates for the tank attach screws, but there was no reason I couldn’t get going on the inspection cover nutplates.

This was another good example of the new minimal instructions.  They just say something like “Countersink the main spar for the nutplates.”  They don’t mention that in addition to countersinking for the covers, the nutplate attach rivets have to be flush too.  So there’s countersinking before you can even get tot he countersinking!

There seem to be some different ways that builders have done this task.  The specific problem is that the countersink cutter needs a hole deeper than the thickness of the spar flange to keep it centered.  Some guys will use drilled pieces of wood for this, but the instructions simply note that a #40 countersink will center sufficiently in the #6 nutplate.  I just went with the Van’s method; I final-drilled the rivet and screw holes, countersunk for the rivet holes, and riveted the nutplates in place.  Then I came back and countersunk for the actual cover plate screws.

Countersinking the rivet holes (I used a block of wood to help guide the countersink cutter):

Nutplates!

And the finished product, nutplates in place and cover countersinks done:

It was somewhere in the middle of this that I made an unpleasant discovery.  See, I primed the spar channels first, then set them aside and worked on the other pieces.  When I finished work on the first main spar, and went to put it by the primed spar channel, I found this:

Not sure what went wrong here.  I scrubbed the spars thoroughly, and was 99% sure they were good and dry before spraying, but maybe I was wrong about that last one.  So I guess I’ll be sanding these down and starting over again.  It’s not really difficult work, but it kind of annoys me since priming was the #1 thing I wanted to get done today.  Tomorrow looks very rainy, and I’ll be out of town next weekend.  But hey, there’s plenty of other stuff to work on…

Yep, that’s all I did tonight.  I didn’t really expect to get a lot done, since I needed to pack stuff for the weekend trip to Chattanooga anyway, but I still wanted to get out and at least touch the project.  I’m still waiting on the backordered stuff, so starting on the tank attach nutplates is a no-go.  Didn’t really want to get involved with sanding down the rear spar channels and re-priming them either.  So I went to the next item on the main spars, where the instructions had me attach two nutplates to the inboard end of each spar.

I’d like to be able to tell you the purpose of these nutplates, but I have no idea.  There are references to drawing 11A of the center section, but that drawing is not with the wing kit, nor does it appear in my preview plans.  So I just gave up knowing what I was doing and just countersunk for the flush rivets and attached as directed.

I looked at moving on to the tiedown attach points, but looking over those instructions and drawings more carefully shows that there’s some fabrication of spacers and such to be done.  Since I didn’t want to get bogged down with that tonight, I went ahead and called it a (very short) night.

I’m planning to be back home Saturday night, hopefully I can get some god work done on those tiedown points on Sunday.

Well, I tried to get some good work done on the tiedowns today, but it didn’t really work out.  First, I had to fabricate four spacers; the tiedown hardpoints themselves sit against the spar reinforcement bars and attach there with bolts.  However, the aileron bellcranks mount at the same location on the other side of the spar, and bolt into nutplates that will be riveted onto the hardpoints.  Since these mount points are inside the spar bars, the spacers go in there.  They’re pretty simple, just 2″ lengths cut from bar stock, with a 1″ lightening hole cut in the center.  They get drilled in assembly with the spar and hardpoint.

I made the first cut using the bandsaw…but apparently I need to replace the blade on that, because it really doesn’t want to cut straight, and wanders pretty badly.  I tried playing with the blade tension to no avail.  As such, my first cut produced a piece that was worthless.  So I made the rest of the cuts using the good old hacksaw, and then cleaned the cut edges up on the grinder.

At this point I had an odd sort of internal debate; the plans call for 3/16″ holes for the AN3 bolts, so I grabbed a 3/16″ bit from the drawer.  I went to check it against the predrilled holes in the spar and was kind of surprised when it didn’t fit.  Hmm, are the holes drilled undersize?  I wanted to be sure, so I got an AN3 bolt…huh, it drops right into the hole.  Even more odd.  Then I got the 3/16″ bit from my El Cheapo bit set…it drops into the spar holes OK.

I decided to drill a hole in my scrap piece using the apparently slightly oversize bit to see how the bolt fit in the hole.  The results sent me in a very different direction; while the bolt fit OK without a ton of apparent slop, the hole I drilled was kind of ugly.  Seems like it’s tough to keep the drill straight while going through thick pieces like this.  So I decided it was time for a drill press before I went to drilling these pieces.  After a little research, I settled on a model sold at Lowes.  

When I got there, though, the parking lot was oddly empty, despite it being about 6:30 and the door stating that they were open until 8 on Sunday.  An employee in the parking lot explained it to me…they closed at 6 due to it being Easter.  Ohhhh…well, so much for getting my drill press today.  Guess I’ll stop by again after work tomorrow.

So I just went ahead and knocked off for the day.  More to come tomorrow…

Started the night by getting the drill press and band saw properly bolted down to the table.  It looks like a real workbench now!  Once the admiring part was over, it was time to get to work on the tiedown spacers.  The pieces were already cut to size, they just needed a lightening hole added before they got drilled in assembly with the tiedown brackets and spars.  The plans call for a 1″ diameter lightening hole, but the problem is I don’t really have anything that will make a hole that size.  A fly cutter would be handy for this, but…yep, don’t have one.  I decided instead to just make the hole 3/4″, since that’s the biggest hole my Unibit will make.  I figure the extra weight caused by making the hole smaller is pretty negligible.

The drill press worked like a charm for this stuff.  First, I marked diagonal lines between the corner of each piece to find the center.  Then I put a 1/4″ pilot hole in each piece, and followed with the Unibit.  The spacer material is a bit thicker than the depth of a step on the Unibit, so I had to actually drill from both sides to get the hole even.  Once that was done, I used a sanding drum on the Dremel followed by emery cloth to smooth out the interior of the holes.  A pass with the deburring tool on the edge of the tool and they were ready for drilling!

I made a lot of aluminum chips during this process:

The completed spacers:

The tiedown brackets are match drilled to prepunched holes in the spar itself.  The plans give dimensions for making a single locating hole in each bracket; these I drilled using the drill press.  Next, a bolt is dropped through that hole and the spar to locate the bracket, and a square is used to position the bracket in place and clamp it down.  The spacers I made before go between the brackets and the spar; I used some blue masking tape to hold them to the spar while I was lining up and clamping each bracket.  Then the spar gets flipped over and it’s drilling time!

That done, I laid out the parts on the bench (labeled so I know where everything goes) and looked back at the directions.  Next step is to drill the spacers to the brackets for the nutplates that will be used to attach the aileron bellcrank.  The spacers will be riveted to the brackets and nutplates, that assembly will bolt to the spar, and the the bellcrank will blot to that assembly. (whew!)  I kind of wanted to keep rolling, but it was past 10:00 and the air drill and compressor aren’t exactly the quietest things on the planet.

I settled for clamping one bracket/spacer assembly together before calling it a night:

I kind of wish I’d kept going on these tiedowns last night, because there was very, very little left to do on them.  Tonight I just clamped the nutplates in placed, drilled the rivet holes for the nutplates, and countersunk the backside of the spacers for the nutplate rivets.  Pretty simple, and not very time-consuming.  After just over half an hour, the tiedown brackets and spacers were ready to be cleaned and primed.

I guess I’ll be doing a lot of priming this weekend; I’ve got these pieces, and I still have to sand down and reshoot the rear spars that I had primer flaking off of a couple weeks ago.

Yup, basically all I did today was deal with primer.  The afternoon was pretty busy for us since it was the first race of the MotoGP season; I’m a pretty strong fanatic and I’ve got Josie thoroughly hooked as well.  So some time had to go to that.  In between, though, I was able to take care of most – but not all- my priming issues.

First off, I decided to work on some of the rear spare reinforcement pieces.  While not as widespread as the spar channels, I had a touch of primer flaking on the reinforcement pieces as well.  I wanted to use those pieces as a test for my “fix” before going to town on the spar channels.  I started by sanding down the flaking areas, getting rid of the flaked areas and feathering out enough that I was removing what looked like well-adhered primer.  Then I cleaned the areas well with a tack cloth before shooting another coat of SEM.  This ended up working pretty well, though I didn’t know that until the end of the day.

Meanwhile, I moved on the priming the tiedown bracket pieces.  I’d already cleaned these pieces earlier and set them out in the sunshine to dry.  Since the pollen was starting to appear, I hit these pieces with the tack cloth as well before priming.  I also used NAPA 7220 on these; I decided from comparing in the past that 7220 was what I wanted to use in the future. (I only used the SEM on the spars because I had it and didn’t want it to go to waste)  There was no problem with the 7220 on these pieces at all.

Finally, it was on to fixing the rear spar channels.  I figured I didn’t have enough SEM to recoat these, so I decided to just sand them down thoroughly and reprime with 7220.  Unfortunately, I only had one can of 7220 on hand, and it went empty before I even got one side of the channels fully primed.  And since NAPA keeps bankers hours, there was no way to get any more, so that was pretty much the end of the day.  I’ll plan on picking up some more primer tomorrow and hopefully finishing up the spar channels tomorrow night.  Then I can finally get to riveting some stuff together!

I also want to maybe call Van’s tomorrow and see if I can get an ETA on my backordered parts.  Straightening and fluting the ribs is a pretty big job I could be getting started on, but I kind of would like to have all the ribs on hand before I get going on that; I like to do things in batches.  Though I guess I could just start working on the main ribs and then the leading edges, and leave the tank ribs for last, since that’s what I’m missing…but in any case, it’s been almost four weeks now since I got my wing kit, with no more information on the backordered parts.