So yeah, it’s been a little while. Most of the people reading this already know about the hilarity that turned my Oshkosh trip into a full two weeks away from home, so that was kind of the first strike. The weekend after I got back I was still dog tired and so I did very little. Then last week, well, I was still trying to corral the post-trip mess. Most of the camping gear just got dumped in the garage when I got home, so I had to get all that put away. Oh, and it’s stupid hot in Houston right now. I had every intention of doing some work last Thursday night; I came home, bumped on the air conditioned, and sat down to dinner. When I stepped out in the garage an hour or so later, it was still obnoxiously hot. I’m not really sure just how workable weekday evening work sessions are going to be for the next few weeks. Maybe if I can get Josie to turn on the air conditioner before I leave work, it’ll be cool enough by the time I get home and eat.

Anyway, today I got up relatively early (for me) and went right to work. I figured I’d at least try to get work done before it got really hot, and I could always knock off in the afternoon if it got too hot. But really, it stayed decent all day, presumably because I kept it somewhat cool out there from the beginning.

The first order of business was to get my workbench back. Assembling the forward and mid fuse on the workbench may not have been the best course of action. I don’t think I realized at the time that these parts were going to be going together semi-permanently, not just for some quick match-drilling. So with Josie’s help, I moved the assembly over to the sawhorses. I almost just put it in a random location, but then I realized that I’d probably be adding the tailcone to this assembly before I was done, and I ought to plan for that. So I set up the platform diagonally, with the firewall by the garage door. Once I join the tailcone I’ll (barely) have enough room to walk around the aft end to get to the other end of the garage. I suspect there will be another garage reorg in the near future…

Then I was able to move on to the tailcone bulkheads that I started on before OSH. I finished up the aft most bulkhead by dimpling the rivet holes and riveting the bulkhead halves together. I also got the tail spring mount primed in between this work. One good thing about the hot weather is that primer dries fast. The next bulkhead forward is a bit more complex, since it incorporates the aft mounts for the horizontal stab. First some material must be removed from the bulkhead halve to accommodate the elevator control pushrod:

Then the halves are clecoed together with vertical support bars for the h-stab and a crosspiece to support the aft deck (just a piece of sheet that goes under the stab mounts):

The rest of the bulkheads are pretty straightforward, but all these pieces share the trait of having lots of little nooks and crannies that are a royal pain to deburr. I spent a lot of time with the needle files today. But eventually I had a stack of bulkheads, all riveted together and ready to go:

Tomorrow I get to start piecing together the other tailcone internals, including the baggage area ribs, rear seat belt lugs, and aft longerons. I might get to the point of adding the tailcone to the fuse assembly, but we’ll have to see about that. It’d be pretty cool to finish the weekend with a more-or-less full-size fuse assembly though…

OK, so there’s still tons to do to get ready for the OSH trip, but I found a little time to do a little work after work today. I match drilled the two F-812 bulkheads, bent the flanges as instructed, and then lined up the tail spring mount and drilled the two keeper rivet holes. That last part took forever, because the drawings here are extremely confusing and vague. After puzzling over them for some time and getting nowhere, I resorted to the internet and found that many others had had the same issue. Fortunately, another builder provided a detailed explanation along with some much more useful drawings and photos, and armed with that info, I finally drilled those two holes, then countersunk them. I stopped short of dimpling the two bulkheads though, because I need the C-frame for that, and I need my workbench for the C-frame, and my workbench is currently occupied by the fuselage assembly. So I’ll just figure all that out when we get back.

Also, my Grove airfoil gear legs finally showed up today. It’s been almost seven months since I ordered them. Grove apparently had some issues with getting this batch of legs heat treated and so they ended up running way behind. I wasn’t really bothered though, since I’m nowhere near fitting the legs, and any annoyance went away when I saw these things:

Whew, back to work again. It’s been a busy week, between wrapping up a project at work while simultaneously trying to get everything organized for our Oshkosh trip. Yesterday I finally managed to get a good weather day and a non-broken plane, and got my spot landings up to a level commensurate with flying to OSH. I’d intended to try and get some plane work done in the afternoon, but nope…ended up being too busy. Today, though, I finally made some time.

When I left off last, I’d gotten started clecoing the left mid side skin in place, but stopped short of installing the left armrest assembly. So that’s where I picked up today. One thing I learned later in the day is that it’s a lot easier to install the armrest assembly piecemeal instead of trying to put the preassembled thing in place. There are about four or five things that have to be aligned properly while you’re maneuvering this fairly floppy conglomeration.

But hey, I got it, so here’s a look at the left armrest stuff all assembled for good:

Next, I went to work on the right side. I got the skin clecoed minimally in place, but I kept having trouble getting the rear bulkhead half slid into place – just didn’t seem to want to line up. Eventually, though, I figured out why – somehow the conical bend on this skin got fouled up, and had one tight angle spot on it. I tried to get an illustrative photo, but it was pretty blurry. Reflective surfaces really seem to confound the autofocus…

So I got the bulkhead out of the way and was able to massage the bend by hand to a better state. Along the way, I made a little guide block out of scrap wood to help me gauge the bend properly. I just traced the outline of the bulkhead and then cut it on the bandsaw:

Finally, I got the skin bent properly and then clecoed the armrest and everything into place. This is basically the rear passenger area, though the back of the front seat will be behind the center section here too:

Then I got to do some match drilling. Not a whole lot in terms of holes, but most of the holes were between the armrests and the side bulkheads, so access was interesting. I used a 12” #30 bit for most of the work, but even that wasn’t enough for a couple holes, where I actually ended up spinning a drill bit with my fingers to final-drill the holes. It wasn’t too horrible, but I’ll be glad if I never have to do that again… With the match-drilling done, it’s time to bring over the forward fuselage assembly and join it to the mid fuse. Surprisingly, this was an easy one-person job. The two assemblies are initially joined with clecos in the lower center section flanges and also joining the mid cabin braces to the top of the center section.

And then it’s time for the forward side skins. I went ahead and deburred the edges of both of these, along with the large punched holes. The left skin was more fun here since there’s the cutout for the NACA duct that will feed the forward air vent. The edges in that cutout were rough, and about all I could use for smoothing were my little needle files.

Once the deburring was done, it was time for a LOT of clecoing. The instructions say to be liberal with the clecos, and it’s obvious why – the skins don’t really want to conform to the bends at the top and bottom of the sides. I’ve got half a mind to try and bend the skins a bit, but I suspect I’d end up doing more harm than good.

And now it really looks like an airplane part. This is basically the entirety of the cabin area; behind this will be the tailcone, mostly empty space but with the rear baggage area behind the rear seat. Ahead of it will be the engine compartment.

Next up: bulkheads for the tailcone. First step here is to separate one angle chunk into several pieces. Two of the will be crosswise angles in the tail, a third is some kind of control stop, and the final pieces will be the rudder stops. Well, I should say that they would have been the rudder stops. I was finishing up the cut on one end of the rudder stop piece when something went horribly wrong inside my bandsaw. It emitted a tremendous bang, froze up solid, and at the same time yanked the piece out of my hand, bashing my right index finger in the process. I’m not entirely sure what happened; the blade had a huge kink and was jammed against the upper and lower blade guides.  The lower blade guide was loose, which might have been the cause, but I suppose it’s also possible that it was loosened by the violent stopping of the blade, so I dunno.

Anyway, the saw wasn’t really damaged, other than the little plastic piece on the table that surrounds the blade passage – that got broken in half, probably when the angle piece was jerked out of my hand. I removed the destroyed blade, installed the spare one I had lying around, readjusted the blade guides and so forth, and it ran like a top again. Unfortunately, it also took an extra chunk out of that rudder stop piece when it went crazy:

I spent some time after this radiusing some edges of the tail angles; they have to be rounded to fit properly inside the longeron angles. After that, I called it a day and – what else – went inside to continue gathering stuff for the camping trip. It’s a lot more fun when you’re weighing every single item and keeping a running total. Such is the joy of airplane camping…

Hopefully I can get a little more work in on the tailcone parts this week, but I dunno. We’ll see, I guess.

So I started out today by looking at putting the bend in the lower aft corner of each mid side skin. First I had to make a run to Home Depot to get some aluminum angle to use for the bending rig; after that, I got to work. The bend here is basically conical, with the forward portion having a small radius of ~1/8”, and a much larger radius at the aft end. The procedure calls for cutting a piece of wood with a 45° angle and clamping it on the skin at the upper bend line, in alignment with the work bench. This sets to upper limit of the bend. The angle is cut in two pieces and the lower end of the skin is clamped between the two pieces, and the bending force is applied to the angles.

Here’s a look at the bending rig clamped in place for the left skin. As you can see, I’ve already put a slight bend in the skin here.

There’s a bevel cut on the forward (left in the above photo) end of the angle to allow it to clear the piece of wood. However, I still ended up making contact towards the end of the bend; I thought this would be OK, but it ends up pushing the wood piece out of place, regardless of how tightly it’s clamped down. Apparently there’s a lot of force applied there at the tight end of the bend. I ended up stopping the bend a little early; the instructions say that it’s better to undergo things here than overdo it.

I actually ended up going back and tightening this up later on, after removing some more material from the end of the angle to allow me to bend a little further. But first I had to take my skin and loosely test-fit it to the armrest/seat rib assembly I put together last night:

The right skin ended up looking a good bit better than the right, as is usually the case when I do something twice. I think the main lessons learned here (for any other builder that might read this) are to avoid contact between the wood and the aluminum angle pieces at all costs, and to clamp way more than you think you need to. At first I tried to just hold the aluminum angle in place with clecos, but it came loose after only a bit of bending, hence the addition of the small C-clamps.

At this point I ended up taking a break; my allergies had been bothered me all morning and I’d been mostly working through it, but I finally have in, took two Benadryl, and surrendered to the ensuing sleepiness. I felt better after that, so after dinner I went out to get a little more work done. First I moved the seat rib/floor assembly to the work bench and clecoed the center section in place, then match-drilled the holes between the seat ribs and the seat rib supports on the aft side of the center section.

Next, a large hole needs to be but in both the right mid side skin and the outer seat rib; this is where the vent hose for the rear seat will pass through. The vent is originally fed from a NACA duct on the bottom of the right wing:

And finally, it was time to start clecoing the mod side skins in place. This is a bit tedious, mainly because it’s tough to access both the cloches and the parts that need to be pulled together. I got as far as clecoing the left skin in place to the seat ribs and rear bulkhead before quitting for the night. I’ll still need to add the armrest assembly here, and also repeat this for the other side. I need to read ahead in the instructions and maybe evaluate if it’s better to add one side skin at a time to better facilitate match drilling and so forth.

Anyway, I’ll close here with some vanity shots of the side skin clecoed in place (more thoroughly this time):

OK, finally back to work. I’ve been a bit lazy this past week, in addition to trying to get a head start on being ready for out trip up to Oshkosh. I started today by working on repeating all the stuff I did previously with the lower left longeron. I ran into a problem almost immediately when I first put the longeron in place:

Yup, apparently I twisted the aft end the wrong way. Fixing the twist wasn’t a huge deal, but it did require a few trial-and-error trips between the vise and the forward fuse assembly before I got the twist just right. Then I set to work doing all the drilling. This is especially fun since a breaker trips if the compressor cycles while the garage air conditioner is running. So when I know I’m going to be doing a lot of drilling like this, I preemptively turn off the air conditioner, which of course means that it pretty quickly starts getting hot. And here I am, sitting on the floor and drilling over my head, with aluminum and steel chips raining down on me…and the sweat makes sure they all stick to my skin. Whee!

Anyway, with the drilling, deburring, and refitting done, I final drilled all the #30 holes on the outboard sides of the gear weldments. This is just to remove the powder coating from the holes and make it easier to cleco stuff together later. Next, for each side, I placed the auxiliary longeron in place, followed by the outer gear tower plate, which holds that longeron in place. The fun part about this is that you’re supposed to cleco from the inside, to allow for fitting the skins at a later time. That works fine on the lower portions of the towers, but for the forward upper areas, the baggage bulkhead gets in the way. So I ended up temporarily removing the forward baggage floor along with the bulkhead, just so I could place a handful of clecoed on each tower. I bet it’ll be fun doing all the riveting up here…

Here’s the left side with the aux longeron and gear tower plate in place. Note that the aux longeron hasn’t been drilled at all, it’s just loosely held by the tower plate. I imagine it will get drilled in assembly with the skin at some later time…

And that’s all for the forward fuse assembly for now. I removed the center section assembly and set it aside, then moved the forward fuse assembly back to the saw horses. That brings us to the mid fuselage assembly, which appears to basically constitute everything from behind the center section to the back of the rear seat; the seat rib assembly from before will be the base for all this. First up is just a bunch of part hunting and deburring. There are four floor angles, a couple of gussets, and ten parts for the rear seat armrest assemblies…and they all have nooks and crannies requiring the needle file to smooth. I spent probably a couple of hours or more just deburring all that stuff.

The instructions also call for you to enlarge a hole in the armrest bulkheads to allow for routing the pitot static line, but they don’t tell you what size to enlarge it to. I spent a fair amount of time hunting through the plans, then searching online, before finally remembering that I have the entire pitot kit from Safeair in the garage. Sure enough, it includes the snap bushings for the line routing, so finally I got past that issue.

Another hangup I’m having involves the rear seat throttle. The instructions say to modify the left armrest now for the rear seat throttle, if one is being installed. Well, that wasn’t an option on the fuse kit, so I don’t have that stuff. The bit of research I’ve done so far seems to indicate that people do lots of different things for the rear throttle, so there’s no one simple answer so far as I can tell. I’ll just have to do some more research and try and figure out what to do here; I can probably delay these modifications without much impact up until the time that I actually rivet the skins on. Maybe I’ll get some good ideas at OSH…

Next up I pulled out the mid side skins, peeled off the blue vinyl, and deburred all the edges. More tedious work here with files and needle files and the die grinder. The next step here is to make a bend at the aft edge of each skin, but it was late enough that I decided to leave that for tomorrow. Instead, I clecoed together the left armrest assembly and then clecoed it to the seat rib assembly, mainly just so I’d have something visual to show for today’s work:

And that’s it for tonight. Tomorrow I should be able to get the skins rolled and maybe have a nice-looking subassembly by the end of the day…

OK, so this wasn’t even a real work night when you get down to it. I wanted to get out and get stuff done since I didn’t do anything over the weekend, but I was also kind of beat after work today and didn’t really feel like dealing with carefully fitting the right lower longeron. So instead I kind of made it a big-picture-planning night, or something like that. Basically I just read ahead in the instructions, looked ahead through the plans sheets, and got an overall view of how things went together. I may have, in the course of this, clecoed the side skins, cockpit rails, and windshield roll bar in place just so I could look at them and giggle. But that’s just a rumor.

Hopefully I feel better tomorrow night so I can get some stuff done. I’ve also got to start seriously thinking about our Oshkosh trip, which is now only a little over two weeks away. Time to start dragging out and weighing the camping gear again…

Didn’t get a lot done tonight. For some reason I was dog tired, but I still managed to go get a little something done. There are two holes that go through the forward floor, the longeron, and finally the outboard gear tower weldment. I’d drilled those initially to #30 before, and tonight I drilled them to the final size of #19, then countersunk for flush screws. Then I pulled the longeron out and deburred all those holes I’d drilled. The plans also call for a bit of radiusing on the vertex of the aft end of the longeron, something to do with promoting a better fit of some part down the road. Then I put the longeron back into place and clecoed/bolted/screwed it in place. The next step is to repeat all this on the right longeron, but that’s for another time, maybe this weekend. After that, looks like I get to fit the auxiliary longerons…

Started out tonight by finishing up some work on the upper longeron gussets from last night. The tabs on the gussets need to be radiused a bit to clear the center section bulkhead, so I took care of that. Another issue I noted was that the spaces between the tabs weren’t quite deep enough to clear the flutes in the bulkhead flange. So I marked a line on each gusset and opened the spaces up a bit to provide proper clearance.

Tabs marked with the required clearance line:

Next I separated, radiused, and deburred four more little gussets that will attach the lower and auxiliary longerons to the center section assembly. Then it was time to move the whole forward fuse assembly onto the workbench and get to work fitting the lower longerons. This is kind of fun; since the longeron isn’t prepunched at all, it has to be carefully fitted and clamped in place. I ended up clamping the thing in place three times. The first time the lineup was off and I had to start over. The second time I realized that I wasn’t going to have sufficient edge distance at the aft end of the longeron, so I removed it and marked the ends of both longerons to show where it was safe to drill:

Finally, the third time, I was satisfied with the alignment…after checking it all about ten times. I ended up with, well, a lot of clamps holding it all together:

Thenm after checking everything a few more times, I got started drilling. This is kind of fun since you have to drill up from below, using the prepunched holes in the forward floor as a guide. This, in turn, means that you get a ton of aluminum shavings raining down on you, along with hot steel chips in the couple of places where you drill through a weldment as well. Fun times!

But eventually, it was done. Well, at least the part where the longeron is drilled to the floor. There are still a couple other spots to drill, but I’ll pick back up on that next time out. In the meantime, here’s the aft portion of the longeron clecoed to the floor:

First up tonight were some reinforcement plates for the center section. These will (presumably) go under the skins at the center section to provide some additional structure and help distribute the loads from the main spar carry-through. These plates are provided as flat stock, but they need to be bent to match the curve of the bulkhead ends. Before bending, I went ahead and filed and polished the edges of the plates; easier to do that when the stuff is relatively straight. Next I set up the bending jig, basically just a pice of lumber set on 1/8” spacers and clamped to the bench. The plate is bent by slipping it under the lumber and applying downward force. By doing this at ~1/2” intervals in the upper part of the plate, the result is a nice gentle curve.

The bending jig:

Next up are similar reinforcement plates for the gear towers. Here again, these plates will go under the side skin, and here again, they need to be bent to match the curve of the upper fuselage. These were made if thicker material than the center section plates, and thus bending them was a little more work. Always fun trying to balance “this takes a fair amount of force” with “no don’t put a big crease there.” After this, there’re two gussets that go at the top of the center section area to help tie it into the upper longeron. Once again, these guys need a curve bent into them.

Finally, after lots of filing, polishing, and bending, I had all these various pieces clecoed in place. Which is probably not strictly necessary, as I’ll soon be fitting the longerons under some of this stuff, but it’s as good a place to store the parts as any, I guess.

And that’s it for tonight.

Whew…another good, productive day. I started out by continuing with riveting on the seat rib assembly. First the floor angles get riveted to the ribs, which is easy with the squeezer. Then the forward and aft ribs get riveted in assembly with the rear spar bulkhead, which is way more fun. The top and bottom rivets are easy enough, the middle two not so much. You see, the seat belt lugs on the forward ribs get in the way of bucking those two rivets. It would have been a lot easier to have riveted the seat belt lugs to the ribs after riveting the ribs to the spar, but I was just following the directions. Anyway, I managed to get the lower of the two annoying rivets shot without too much trouble: (the assembly is upside down in this photo)

For the other pair, I decided to use MSP blind rivets in place of the solid rivets. I would have done this for the other pair as well, but those rivets go through the spar bars and so there’s far more material thickness, enough that I don’t have any appropriate blind rivets around.

Next, I moved the assembly to a pair of sawhorses, clecoed the bottom skins in place, and went to work riveting them. This was a bit awkward at times, but not too bad. Here’s the finished assembly: (note my markings so I know what not to rivet yet)

That completed the seat rib assembly, so next I moved on to the real fun: bending and prepping the various longerons. There are three pairs of longerons that get bent here; the lower forward longerons which run along the forward floor from the firewall to the center section, the auxiliary longerons which also run from the firewall to the top of the center section, and the 16’ long main longerons which I believe run all the way from the firewall back to where the tail mounts.

Each lower forward longeron already has a bend preformed in its middle; I get to add a twist on the forward end, then the rear angle is opened up, and finally the rear end gets twisted as well. Twisting is performed by clamping the longeron in the vise and grabbing the end with a crescent wrench and applying some muscle. I used my digital level to measure the bends; here it’s showing the pre-bend state of one of the lower longerons:

Opening up the rear angle is fun. Basically you put the open end of the angle on a hard surface and then beat on the vertex of the angle with a big hammer. (Actual line from the instructions: “If you cannot get the angle to change…get a bigger hammer”) It takes a pretty impressive amount of force to open the angle. I was taking full swings with my deadblow hammer. I got Josie to come out and take some photos, since it’s been a while since I added some “prove you built this thing” pics.

And twisting the aft end of one of the longerons:

The auxiliary longerons are easier; they just get a gentle bend added to one side. This is done by marking the longeron at ~2” intervals and progressively clamping the longeron at each mark and giving it a good whack (that’s the technical term from the instructions) with the hammer. Then we move on the real fun, the main longerons. Each longeron has two bends in it, and both bends are made in two dimensions; that is, down and inboard for the forward bend and up and inboard for the aft bend. It’s still just a matter of clamping the longeron in the vice and assaulting it with a hammer, but given the length of these things, I was forced to turn off the A/C and open the garage door:

I’ve seen builders seem to stress about these bends, and I suppose I can see why: if you ruin something, you get to pay shipping for a 16’ long box, which can’t be cheap. Hoever, I found making the bends to be pretty straightforward. There is an element of trial-and-error due to the two-dimensional bends; bending in one dimension tends to change the bend in the other dimension, so there’s a lot of back-and-forth until everything is right.

Of course, since the first longeron was fairly easy, I got complacent with the second one. I clamped it in the vice so I could measure and mark the bend lines, then went to town bending…only to realize I hadn’t moved the longeron so the bend line was in the right place. Yep, I bent it at the wrong spot. Fortunately, I was able to straighten the misbend and then get everything fixed up properly. I wanted to take a photo of the completed longerons, but it turns out it’s tough to take a good photo of something 16’ long and 3/4” square.

I was about ready to call it a night at this point, but I wanted to read ahead in the instructions and see what came next. I’d kind of figured that I’d move the forward fuselage assembly and clamp the longerons in place to kinda sorta store them, but it turns out that the main longerons don’t actually get installed until way down the road. So now I’ve taken two long angles that I had stored nicely, and bent them to where they’re way more annoying to store. I ended up cutting a few pieces of paracord and hanging the bent longerons from the garage door tracks right beside the other long angle stuff.

From this point, it looks like I get to fit the lower and auxiliary longerons to the forward fuse, along with some additional structure for the center section and gear towers. Guess I’ll find out about that stuff tomorrow night…