OK, we left off last time when I’d clecoed the seat back support into place. The support attaches to the side mount plates with AN4 bolts, and to the cockpit rails with a combination of -4 rivets and flush screws. The prepunch situation here is kind of odd; the cockpit rail holes that will hold rivets are prepunched in the rails and the spacer between the rails and the support. These holes are simply match-drilled through the support. But the holes that will hold screws are prepunched in the support, but not the rails or spacer, so they have to be match-drilled from below. (aka inside the cockpit)

The instructions say to drill the screw holes from below first, then the rest of the holes from above. But an issue here is that the 3/8” clecos I used to initially hold the support in place weren’t strong enough to pull the support fully into position. This is easily fixed with some clamps, but it makes drilling from below even more difficult. So I decided to drill the holes from above first, with the support clamped firmly in place. Then, with clecos in all those holes, the clamps could be removed and the support would stay in place.

That part was pretty easy, but next came drilling the support from below. I experimented a bit with trying to do this while leaning over from outside the cockpit, but I wasn’t at all confident in my ability to drill square to the surface, so I resigned myself to working inside. I prepared for this by tossing some scrap 2×6 pieces in the cabin. These are thick enough to at least make the rear seat crotch strap mount not jab into me while I work:

And of course, once I climbed in there and laid down, I immediately realized I needed something else. Fortunately, I was able to get Josie’s attention so I didn’t have to climb back out. And of course, she couldn’t resist getting some photos of me being uncomfortable:

With that annoying task taken care of, I finished the support by drilling the screw holes out to #19, then match-drilling all the remaining holes. Next the center section bulkhead caps are match-drilled, then removed. I’m not sure why they were called out to be removed at this time, but I guess I’ll find out later…

Next up were the rudder stops. When I was cutting the piece of stock containing these pieces before, the blade on my bandsaw snapped and put a nice nick in one of these. At that time, I just decided on a whim to skip these external rudder stops in favor of an aftermarket solution that went inside the vertical stab spar. However, I did some more research on this topic today and it seems that there’s significant debate about those internal rudder stops. While there don’t seem to be any cases of damage or accidents resulting from the internal stops, a fair number of people (including one of the Van’s engineers) have expressed concerns with the internal stop causing increased stress on the vertical stab spar and the rudder hinge points.

After thinking it over, I’ve decided to use the factory external rudder stops instead of the internal ones. It turns out that the nick the saw blade put in the stop isn’t a problem anyway, as that part of the stop will be trimmed off later on. So I went ahead and clecoed and match-drilled the rudder stops in place:

Next up is fitting the tail spring mount. Previously I drilled the mount hoes in the aft most bulkhead, and now with the tailcone together, it’s time to fit the mount and drill the holes in the next most forward bulkhead. The first thing that has to happen is the removal of the aft bottom skin. Well, that’s kind of a problem, since that’s exactly what’s resting on the sawhorse holding the tail up! Hmm, what to do…I considered modifying the saw horse so I could support the tail under the longerons, but that would have left the saw horse in my way while I worked on the tail spring mount. Finally, I realized that the two interior garage door track mounts in the ceiling were almost directly overhead the fuselage, just aft of the cabin. I tried running a ratchet strap between those two mounts, slung under the fuselage, and found that it was in a good location – about 6” aft of the aft cockpit bulkhead, and under the area reinforced by the baggage ribs. I lifted the fuse gently at first, confirming there wasn’t any distortion or buckling happening underneath, and it worked out great. (except I forgot to take a photo and now I’m too lazy to go back out and take one, so you’ll have to use your imagination)

Next I marked the forward bulkhead with a reference line, which I’ll want to align the top of the forward end of the mount:

With the mount in place, there’s a bit of a gap between the forward end and the bulkhead. This is somewhat expected, as the instructions call for making shims as necessary to fill any gap:

Here I departed slightly; the instructions specify 3/4” square shims, one for each of the two bolt holes. I elected to make a single shim that stretched all the way across the top of the mount; for one thing, it seems this will prevent the annoyance of individual shims spinning in place, plus there’s a little more contact surface between the mount and the bulkhead. That may well not make any difference, but I like it anyway.

Now the forward portion of the mount gets moved carefully into position and clamped in place. In addition to using the reference line drawn previously, the instructions say to use the tooling hole in the forward bulkhead as a reference also, by sighting down the mount tube and centering it like so:

Finally, there’s nothing to do but check everything one last time and drill the holes. Here’ the mount in its final position, held in place only by clecos:

Now the aft bottom skin has to be trimmed to account for that mount passing through it. There’s a nice full-size template in the plans for this, which I traced onto a sheet of paper:

Then taped in place on the skin:

And then a cut line is traced onto the skin:

I’m not really 100% satisfied with how that traced cut line ended up though; it looks asymmetrical to me. I know it’ll end up being tweaked to fit the mount, but I want it to start off being straight. In any case, it was getting late by this time and I didn’t want to get into making the cut anyway, so I quit for the night. I’ll do some more research and see if I can get good ideas on marking and cutting here from other builders.

Well, didn’t get a lot done today. I got a bit of a late start, and after a couple hours work I broke for dinner, and about the time the power went out for what ended up being four hours or so. That kind of put a damper on the possibility of working into the evening…

Anyway, drilling the rails was kind of interesting. The instructions call for positioning them so they’re flush with the mid side skins, but with the rails clecoed to the tops of the center section bulkheads, there was 1/8” or more between them and the mid side skins. I was able to push on the longerons and bit and move them in close, which leads me to believe that the reinforcing plates between the skins and bulkheads aren’t quite sitting fully flush with the bulkheads. So I ran a ratchet strap around the fuselage and was able to use that to pull the longerons into proper alignment. I also used the strap to pull in the longerons at the gear towers, and drilled the five holes at the top of each tower to the longerons.

Next I clecoed the seat back support mounting plates in place and match drilled them, followed by the spacers that go between the rails and the seat back support weldment. Finally, I brought over the seat back support itself and clecoed it into place. At this point, I decided that the fuselage structure was sound enough for me to climb into this thing for the first time. I laid a piece of scrap lumber over the seat ribs and added some old towels for padding, and in I went.

Funny part was, as soon as our dog saw me sitting in there, he climbed up the stool to investigate, apparently trying to get in with me. Sorry Dude, it’ll be a few years before you can ride in here:

Tonight I started by match-drilling the holes between the lower center section flanges and the forward floor and bottom skins. For some reason I’d thought that the instructions specified these be drilled from the inside, but apparently I dreamed that. That’s fine with me, because there’s lots of stuff in the way inside and nothing on the outside. The only downside was that I had to lie on the ground under the fuselage.

Next, I clecoed the aft bulkhead tops into place, then pulled the aft top skin out of the guest bedroom and clecoed it into place:

Then I fitted the aft deck and drilled it in assembly with the longerons. The horizontal stab assembly will sit on top of the aft deck when it’s installed. Here’s the deck clamped in place prior to drilling:

Next up will be the forward canopy rails…tomorrow…

OK, not really a work day per say; all we did was get the fuselage off the old “platform” and onto the new sawhorses. We moved the fuselage out of the garage and into the lawn first. I took advantage of the newfound room to sweep/vacuum the floor, and roll the compressor out into the driveway and drain the tank. Then we positioned the new saw horses and moved the fuselage right back into place. I planned the saw horses pretty well – the upper longerons are within a few degrees of being level!

Next I’ll get to do…more match drilling. Whee!

Well, this was mostly a day spent stress testing my air drills and compressor. Prior to that, though, I made a Home Depot run for some lumber, with which I made a couple of sawhorses. Now that I’ve finished drilling the tailcone, we’ll need to move the fuselage to these so it sits low enough for me to easily lean inside and do some drilling from in there. The sawhorses are specially-made for this job; one of them is 3’ wide but only a foot tall, and will sit under the forward end of the fuse, while the other is 2’ tall but only a foot wide, and it will support the tail. These should result in the fuselage being roughly level while it’s on the horses. I’m going to add some angle-cut blocks on the tail horse to help hold the tail securely, so that will allow me to adjust the level attitude if I wish – though there’s no particular call to have it be level right now.

Anyway, these are the saw horses:

And now back to the fuselage. With all the drilling done on the forward side skins, next the mid side skins get drilled. First the upper longerons are drilled in assembly, then all the other holes get match drilled. Next up are the aft bottom skins; these are lots of fun since I basically have to lie on the floor while drilling. And then the real fun begins, drilling the aft side skins to the longerons. This isn’t particularly challenging, there are just a l-o-t of holes. Once I got my drilling rhythm down, I think the compressor was usually running for 10+ minutes at a time. It actually got to a point where moisture was blowing through/out of the drill; I guess the air in the tank was so saturated that the water was condensing as the air expanded in the hose. I guess I’ll be wanting to go ahead and drain that tank again soon…

Here’s one of the longerons clamped to the aft side skin prior to drilling:

And a forest of clecos on the other aft side skin:

Speaking of clecos, these are all the silver ones I have left over after all this work, with the exception of a can of pretty junky ones on a shelf somewhere. Hopefully I don’t have to use those, I don’t want them fraternizing with my nice shiny clecos:

I think tomorrow we’re going to go to an AOPA safety seminar in the evening, so I suppose Tuesday we’ll move the fuselage assembly out of the garage, get the floor swept (all that drilling made a ridiculous mess), and then get the fuselage set up on the saw horses. Pretty soon the aft top skin will go on, along with the cockpit roll bars, and at that point I think I’m going to have to throw a pillow or something in there and sit in this thing for the first time.

Started out today by beginning to rivet the rear seat. This was somewhat interesting due to the shape of this thing. In general, it was challenging to find some way to hold the pieces steady while I riveted; in particular, the curved top section made it awkward to use the squeezer. So what I’m getting it is that it took a little longer than I expected. But still, it’s done, and so I of course put it in place in the fuselage for a photo op:

Then I got back to work on drilling the fuselage. I got through drilling everything on the left forward side skin before quitting for dinner. Looking ahead, and based on the rate I was going at today, I think it’s possible I could finish match drilling everything back to the tailcone tomorrow. I’m going to run to Home Depot in the morning to pick up materials to make a couple sawhorses; the setup I have now is kind of wobbly and not exactly confidence-inspiring, plus I’ll soon need to climb into this thing to do some match drilling, so I’ll need it lower to the floor and definitely on something more sturdy than these cheap plastic sawhorses.

Tonight I finished drilling one hinge half to the seat back and then clecoed the whole thing together for match drilling. Pulled it apart, deburred everything, and started to to some riveting, then decided to just wait until tomorrow. Once I get this seat back riveted, I’ll put it aside and get back to all the fuselage drilling.

Short night. I started working on the rear seat back, even though I got in my package from Avery that included new shiny drill bits. I think I’ll wait until the weekend to go on another drilling spree.

Most of tonight was just deburring the edges and crevices of the seat back parts. The rear seat is more complex than the front one, so lots more little spots to clean up. Then I cut the hinge for the bottom of the seat. The plans call for removing four eyelets in the center of the hinge. I’m not quite sure yet what this is for; I guess something passes through here, but I dunno what.

That’s about it. I should be able to finish this seat up Friday, and then this weekend it’ll be back to drilling the fuselage.

Got a late start today, mainly because I stayed up way too late last night. No, I wasn’t partying, I just decided to tinker with panel designs again before bed, which resulted on me being up until about 5 AM. Yes, I lead an exciting life.

Pretty simple task today really, doing the front seat back. There was a little extra work – for whatever reason, one of the two large angle pieces lacked two of the prepunched holes, so I clecoed the two angles together and used the fully-drilled one as a guide to drill the second. Then there was just cleanup of the angles and seat back panel, cutting a hinge section for the bottom of the seat back, and match drilling everything. I primed the large angle pieces, let them dry for a bit, and then riveted the entire assembly together:

Next up will be the rear seat back, which is a fair bit more complex…

Started out this morning by fixing the right longeron. I’d previously marked the location of the canopy rail slot (where the bend line was supposed to be located), so once I removed the rail, I could easily measure between the bend mark and the slot mark to figure out how much I needed to trim off the forward end. I also double-checked the aft bend line to estimate where it would end up after the trim. That bend was actually a bit further aft than the left longeron as well, so the desired trim would move it to be very nicely in line with the left side.

Pulling the longeron was actually simpler than I thought. The instructions say to remove the top ~6” of clecos all the way down the fuse, but the only area where this is really needed is at the forward end, where the longeron has to slip horizontally into the gear tower and firewall angles. Everywhere else, the longeron just drops in vertically, with no obstacles. The fun part was actually making the cut. Fortunately, the door to the garage lines up nicely with the band saw, so I had Josie stand in the kitchen holding the aft end of the longeron while I cut the forward end in the band saw. After I’d polished the cut ends and replaced the longeron, it lined up nicely.

That let me finally move on to drilling. (well, after I’d clecoed the longeron gussets in place) First, the upper longeron gets clamped carefully at the forward end to ensure it’s flush with the engine mount weldment in both axes:

Then, the drilling starts, actually with the lower longeron first. That’s easy since it’s pretty well held in position and there’s no alignment to worry about. Next if the auxiliary longeron, which isn’t really held in position. I drew a centerline on these way back when I started to cleco the forward fuselage together, and you’re suppose to align the line in the prepunched rivet holes, but I couldn’t for the life of me get that line to appear at the forward end. Finally, I figured out that if I removed a few clecos at the forward lower portion of the skin, it’d free the longeron up to be moved a bit. Finally, I was able to drill that.

Then, finally, it was time to work on the upper longeron. I worked my way back to the aft end of the forward side skin (that was the sort of sub-area I was working on), being careful to cleco as I went, back up any flanges that might get pushed out of the way as I drilled, and continually checking the alignment of the longeron. Finally, I went back with reamers and final-drilled all the remaining prepunched holes.

There are quite a few clecos in play up here now:

After a quick break, I got started on the left forward side skin…but I didn’t get very far. On about the sixth hole in the lower longeron, my drill bit caught on a cleco inside the cabin and promptly snapped. Turns out it was the last #30 bit I had around, except for my really long bits. I tried one hole with my 6” bit, but it was stupidly dull – must have been a bit that came with my secondhand tool kit. So that pretty much put a stop to longeron drilling for the weekend. I could possibly have run to Ace Hardware – they do sell numerical drill bits – but I’ve been down that road before and I found those bits to be pretty low-quality. So I’ll just wait to get good bits next week.

That left me with some thinking to do about how to proceed. The following steps are all pretty linear – progressively match drilling the entire fuselage, then ripping everything apart for deburring, dimpling, and eventually final assembly. So there’s not really an obvious place to skip ahead to. Finally, after reading waaay ahead, I found the seat assembly instructions. These seem like fairly independent tasks, so I’ll play with these for the next few days rather than just sitting on my hands.

I took the time to find all the parts for the from and rear seat backs, then clecoed them together just to get a look at the structure. Tomorrow I’ll work on actually dealing with these, including cutting and drilling the piano hinge that will go at the base of each piece. Hopefully there’s enough seat stuff to make a good day’s work tomorrow…

Front seat back: (that’s not a confusing phrase at all)

Rear seat back:

Note that the rear seat is a lot wider than the front one. I’m not quite sure the reason for this – well, the rear seat is as wide as it is because it basically fills the entire fuselage profile and serves as a door to the baggage area – but I dunno why the front seat is so narrow. Anyway, that’s it until tomorrow…