So this weekend has been kind of busy, and I haven’t had as much time for airplane work as I expected…but it’s kind of OK, because I’m discovering that this riveting work is kind of physically trying. The combination of bending over and frequently reaching down into the fuse while handling the rivet gun and the bucking bar…well, my arms get tired pretty quick, and then I try to stand up and my back has some unkind words for me. But I’m making it through…

Today I shot the last remaining row of rivets through the aft center section bulkheads. Then I shot all the rivets from the forward side skin to the left gear tower – I decided that the -5 length rivets were OK after all. Finally, I riveted the junction of the left mode side skin to the aft side skin. This was a fun spot – the instructions say not to rivet the rear armrest until after this junction (which also included a bulkhead) was riveted. I understood why once I got to it – there’s one rivet that is impossible to buck with the armrest in place. The armrest has to be unclecoed and swung up out of the way. Once the bulkhead was done, I riveted the armrest to the skin.

Finally, I moved back to the aft side skin and riveted the next two bulkheads. This still leaves the two aft most bulkheads, but at this point I felt like it was time to call it a night. I’ll probably need two more evening work sessions to get the right side of the fuse to the same point, then I’ll have to decide whether to try some of the more difficult rivets solo, or if I should flip the “canoe” and get into two-person riveting mode.

In the meantime, here’s the left side of the fuselage, mostly devoid of clecos:

This will be a straightforward post. I did basically nothing but riveting today, mostly on the forward side skins. I took care of most of the rivets through the gear weldments, the auxiliary longerons, and the joint with the mid side skins, including the rivets through the forward center section bulkheads. I also squeezed the keeper rivets through the upper longerons, but here I did the rivets all the way from the firewall to the tail. No reason not to, plus they provided a nice break from some of the contortions required for shooting the other rivets.

I initially skipped the rivets through the gear tower side flanges, because when I checked the rivets called out in the plans, I felt they were too short, and there were nowhere near enough of the next longest ones to get the job done. So I was going to just order a bunch of the longer rivets, but later in the day, I checked the length again, and while they were a touch short, it was nothing show-stopping. So I guess I’ll use the called-out rivets after all…tomorrow.

Over the next couple days, I think I should be able to finish all the rivets that can be done solo, then I’ll have to recruit Josie for some of the more obnoxious ones. But I’m hoping to have all the riveting done by next weekend.

I also couldn’t resist doing another one of those mostly-pointless temporary assemblies just so I could cackle at the airplane-looking thing I’d created. I put the windscreen frame in place and clecoed the forward top skin in place, then added the setback support for good measure:

So this is kind of a milestone. Tonights work session makes it an even 1000 hours that I’ve put into this project so far. I even went so far as to take a special photo of tonight’s last rivet, the 1000-hour rivet:

Anyway, tonight’s goal was to get the forward side skins clecoed in place and maybe a few rivets shot as well. Before the skins can be installed, though, the joint between them and the firewall flange must be sealed. The other night, I dug out my tube of Fire Barrier 2000 and cleaned out the dried stuff in the nozzle – or so I thought. In truth, I ended up spending another half-hour or so digging crud out of the nozzle before it finally started to flow freely. Only then was I finally able to lay a thin bead along the firewall flange and put the skins in place. This joint won’t actually get riveted for some time – when the cowling is fitted and the piano hinge is installed for the joint. So for now I just clecoed every hole to get a good clamp while the sealant cured (visible at the left part of this photo):

Next up, there are a few blind rivets at the bottom of the forward and mid side skins where they sit atop the center section bars. The corners of each skin have to be pulled out to get these blind rivets set, so that’s done now, while adjacent clecos can be removed to help out:

I actually got a bit concerned after setting these rivets – turns out I was only supposed to do the two in each mid side skin. At first I thought the forward bottom skin might sit in assembly here, but upon closer inspection, that doesn’t seem to be the case. I think having the blind rivet will just make it a little more difficult to get the bottom skin edge in place between the forward side skin and the lower longeron. I’ll poke around the instructions a bit to confirm – I can always just drill those out tomorrow if I have to. I’d rather not, though, simply due to the danger of drilling too far and into the are, which would be bad, bad, bad.

Finally, I began setting solid rivets along the top of the forward side skin. Most of the rivets between the skin and the upper longeron are also in common with the forward top skin, and so they’re left open for now. Only a small number of keeper rivets, which will lie under the top skin, are set. Most of these I was able to set with the squeezer, but a couple required shooting. No big deal.

Tomorrow I’ll start shooting lots and lots of rivets between the forward side skins and the understructure. I was thinking there would be a lot of two-person riveting for the fuselage, but now that I look more closely, I think the vast majority of these rivets I can shoot solo. Only the rivets on the bottom of the fuselage are going to require two people, I think…well, maybe a few others in odd places as well. But in general I feel they’ll be the exception, not the rule.

Well, this barely even qualifies as a work session, but hey, I did do stuff. I picked up some more epoxy on the way home today – this turned out to be helpful after all. The JB Weld I was going to use originally would have been dark gray, but I was able to get some clear stuff. This way, if there’s any excess that squeezes out, it won’t be obvious and ugly.

Anyway, back home, I cleaned the surfaces one last time, mixed up some epoxy, applied it to the perimeter of the vent, and stuck it in place:

Then I weighted it down with – what else – a jug full of clecos:

Aaaand that’s it. Tomorrow I figure I’ll apply the firewall sealant to the forward side skins and cleco them in place. Then it really and truly will be some for some riveting.

So this actually covers work done last night and tonight. Somehow I managed to forget to even write a blog post yesterday…

Yesterday I left work a bit early, just so I could shoot paint on the forward side skins. I taped off the area where it’ll mate with the firewall, since that will get a bead of sealant when it goes together. I also shot paint on the forward baggage bulkhead assembly while it was out of the plane and I was in a painting mood.

Tonight I back riveted the stiffeners and various mount angles to the forward side skins. This was pretty straightforward work, and initially I figured I’d go ahead and install the skins on the fuselage. But then I got to looking at the hole on the left skin where the fresh air intake duct mounts. It seemed far easier to glue the air scoop in place with the skin sitting on the bench, so I decided to do that.

Many guys glue the scoop using Proseal leftover from the tanks, but I tossed the bit of leftover I had some time ago, so that wasn’t an option. Several builders had perfectly good results with JB Weld, so I decide to do that. But first, I had to position the scoop and clean the paint off the mating area on the skin. That took a bit of trial and error followed by some elbow grease. I wish I’d thought of this before I painted the skin; I would have just masked this area from the beginning and saved some work. Oh well.

Finally, I had the cleaning and scuffing done:

Now I just had to mix up the epoxy and glue the scoop on. Except…um, where’s my JB Weld? Oh yeah, now I remember – last time I organized the tool cabinet, I found the tubes were leaking and so I tossed them in the trash. Whoops.

So that was pretty much the end of work for the night. I guess I’ll get some more epoxy on the way home tomorrow and glue the scoop on then.

Not the most productive weekend – had a lot going on yesterday, and then I apparently somehow injured my ankle and could barely walk this morning, so I spent half the day in bed. But it got better enough for me to get some work done by the afternoon. First, I drug the aft bottom skin out of its storage spot and out into the driveway. I wasn’t looking forward to dimpling this thing, but really, most of the holes were along the edges and thus accessible with a squeezer. I only had to drag out the C-frame for about 30 holes or so.

Then it was time to wrangle that thing into place. Again, this was not a task I was looking forward to; when I installed this for match-drilling previously, it took forever to get the forward end lined up. This time, though, it actually went a lot better. After some initial frustration, I finally figured out where the major problem was – the right mid side skin, where I curved the skin around the bottom of the fuselage, was actually a bit flat in the middle, creating a point where it wanted to bind against the aft bottom skin. I was able to pull the mid side skin out of the way enough to slid a small zip tie into the spot where the binding was occurring, and that allowed me to get the aft bottom skin in place surprisingly easily. Then I just had to install a boatload of clecos all up and down the thing.

That just left the forward side skins to install. First, I needed to rivet some nutplates to the stiffeners/angle mounts for the throttle quadrant and console. Then, these angles needed to be back riveted to the forward side skins before they were installed. So I got out all my back riveting stuff, pulled out the forward side skins…and realized that the inside surfaces needed to be primed and painted first. And here it was nearly dark already. ARGH!

Instead of my usual wet cleaning/scuffing routine, I scuffed the skins while dry and gave them a good acetone wipe down. This was a lot faster and gave me time to at least shoot primer on the skins before it got dark, but the paint will have to wait until another day. Maybe I can bail out of work a little early tomorrow and get the paint done before dark – such is one benefit of long summer days.

I’ve also got to seal the forward side skins to the firewall edges when they’re installed. I dug out my tube of Fire Block 2000 with some trepidation – it’s been sitting since I sealed the forward floor to the firewall about a year ago, and I was concerned it might have dried up. There was indeed a nice plug of dried stuff in the nozzle, but I managed to clean it out and get the stuff flowing again. So now I just have to get that painting done…

Finally, I got Josie to come help me manhandle the fuselage off the big sawhorses and onto the two purpose-built ones. This support the fuselage much more securely, though I don’t know how well it’s going to work once we get started riveting. Most people invert the fuselage for that job…if I do that, I may have to build yet another set of sawhorses. Something else to figure out…

So anyway, here’s the fuselage in its almost-totally-clecoed state:

Last time out, I started riveting the aft most bulkhead in the tail to the aft bottom skin. Tonight, I worked on finishing up riveting that bulkhead in place. It’s a bit of a pain working inside the tight curvature of the bottom skin here, but I got the first bulkhead done without much trouble. One of the rivets I shot last week had to be drilled out and replaced as well.

Next, the other bulkhead – with the attached tail spring mount – is clecoed and riveted in place. This was where things got really hairy. Not only did still have the tight curvature, but now I had the tail spring mount in the way as well. I actually ended up removing the two bolts I installed last time just to get some clearance to work – there were two rivets that I don’t think I could have done otherwise. Even with that little compromise, these things took a long time, I think about ten minutes per rivet on average. Another complicating factor was that the bulkhead tabs didn’t want to sit flush against the skin, so I had to get creative with methods to clamp the tabs while I riveted.

But finally, it was done, so I installed the aft bottom skin assembly in the tail, along with the lower longerons:

Next up is the accursed forward aft bottom skin, which I’m not looking forward to. That thing was a huge pain to get in place last time. At least this time I can take comfort in knowing that it’ll be done with. But first I’ve got to dimple the thing, it’s still waiting for that. I honestly might work on installing the forward side skins first, we’ll see.

So I’ve reached a point where I’m satisfied with systems work inside the cabin, and I’m ready to get back to assembly. Technically, the next task ought to be adding the forward side skins, but that requires back riveting some angles and sealing the firewall joint and other stuff that I didn’t feel like messing with tonight. So instead I moved forward with tailcone work.

First item of interest was the F-812 bulkhead assembly. The horizontal stab attach bars were riveted in place along with the upper support angle. Next the tail spring mount was clecoed and clamped into place, and the two previously-drilled #30 pilot holes were opened up to their final size of 1/4”. All the parts got deburred, and then I bolted the tail spring in place and added torque seal:

The next step was to cleco the F-811 (aft most) bulkhead to the aft bottom skin and rivet it in place. This is kind of an obnoxious assembly since the bend of the skin is tight, and the bulkhead flanges really don’t want to sit flush against the skin. I shot about half of the rivets here, with mixed results, before getting frustrated and deciding to call it a night. There are at least two rivets that I think will need to be drilled out in the next work session. Oh well…

Tonight I went to work on the mechanism that allows the pedal to be adjusted. The main part of the locking mechanism consists of six thin aluminum spacers, two steel lift levers, and a center aluminum piece to which the adjustment cable attaches to. All these parts had to be deburred, drilled to final size, and finally riveted together. Then the lock pin was fabricated from a 1/4” clevis pine; here, you just cut off the tang of the pin, smooth and chamfer the end, and insert a long roll pin into the cotter pin hole. The roll pin is engaged by the lift levers to pull the lock pin out and allow the pedal assembly to move.

With the lock pin complete, the lock assembly went into place. Pretty simple here, the mechanism pivots on another 1/4” clevis pin, with a stiff spring to keep the locking pin in place unless the release cable is being pulled. I installed the pin, bent the cotter pin, and…the pedals wouldn’t move. Apparently I made the locking pin a bit too long. So I removed the mechanism again (that cotter pin had a really short lifetime) and trimmed the lock pin a bit. That was kind of obnoxious with the roll pin installed; the first time around, I just chucked the pin into a drill and spun it against the bench grinder to get the length right and add the chamfer. This time, I tweaked the length by just filing away at the thing, and then rotating it against the bench grinder by hand to add the chamfer. It didn’t look nearly as nice as last time, but it won’t be visible anyway.

This time, with the mechanism in place (which I tested before bending a second cotter pin), the pedals moved and locked correctly. Here’s a close-up of the mechanism:

That only left one more task: cutting the release cable to length and attaching the handle (just a 2” piece of tubing with a hole drilled in the middle). And this was where things went awry. The instructions are to cut the cable to “the desired length, leaving 5/8” for a knot at the end of the cable.” For some reason, I decided the best course of action was to just cut the cable 1” longer than it needed to be to clear the guide with the pedals full forward. After running the cut cable through the handle and beginning to tie the knot, I was thinking that it looked too short, and sure enough:

At the current length, the two forward most positions are unusable. The main issue with fixing this problem is that the cable was preassembled, with the loop already crimped in the end and through the locking mechanism. So a replacement part from Van’s would require replacing the entire locking mechanism. I suppose I could make a new cable myself, but I’m not sure if I need special tools to crimp the loop in the cable properly. Something fun to investigate, I guess…

UPDATE: It didn’t take much research to discover that the proper tool for crimping Nicopress sleeves is…quite expensive. On the other hand, the necessary replacement parts from Van’s are about $25. It’s not really imperative that I get these parts in anytime soon, so I think I’ll add them to a parts order backlog, something I’ve been thinking of doing for a while.

Today started with some general cleanup. I still had the pile of tubing scraps from yesterday’s photo op, in addition to all the tools and various other related stuff lying around. So it took about half an hour to get to a point where the workbench was usable again.

The pedal system is relatively straightforward as systems go, but still mildly time-consuming to construct. First, small pilot holes are final drilled to #12 for the mount points to the forward floor and firewall. Then the assembly is bolted in place temporarily and mount holes between the slide bar and end socket are drilled. The whole assembly comes out, stuff gets deburred, and then it’s time to drill the assortment of position holes in the slide bar. These hole determine the possible positions of the pedals.  The plan method here is a bit convoluted for my taste; they want you to drill the forward- and aft-most positions, disassemble everything, mark the positions of the remaining holes, reassemble, and then align the pedal with each mark and drill a hole at that point. It seemed a lot easier to me to measure the length of travel, mark the exposed slide bar at appropriate intervals, and just slide the pedals to each new position to drill. So that’s what I did.

Here’s the slide bar marked for each position (sorry for the blurry photo):

And a look at the holes with the pedals in the aft-most position:

Next, the rudder pedals go in place. The pedals are retained by plastic end blocks which bolt through the rudder pivot bar; these blocks are carefully positioned and then bolt holes are drilled through the pivot bar. Disassemble, deburr some more, and then the pedals go in place permanently.

Then it’s time for the brake pedals and master cylinders. The pedals themselves are welded aluminum units, and like anything in the kit made from thick aluminum, the edges are pretty nasty. So I spent a fair amount of time cleaning up the edges. Then the master cylinders have to be prepared by installing the brake line fittings. The fittings are clocked slightly inboard to provide proper clearance:

While the pivot points for the brake pedals are predrilled, the hole to connect the upper master cylinder is not. The plans call for a specific location, and note that pilots with large feet may wish to drill the holes a bit higher to avoid inadvertent brake application. I don’t think my feet are that big, but I don’t want inadvertent brake application, so I drilled the holes 1/8” higher than specified.

I actually messed up a bit here. The instructions only have you drill one pedal to start with, then put everything together with the pedals aligned, and then the hole location in the other pedal can be marked. This is to ensure that both pedals are aligned. Well, I just marked and drilled both pedals before reading this bit. But after temporarily assembling everything, the pedals still align OK, so nothing to worry about here.

Here’s the final assembly from the aft (pilot-facing) side:

And from the forward (firewall) side. Note the tape over the brake fittings – I don’t want any foreign material getting in there!

And that’s a good day’s work. Next up, I’ll put together the locking mechanism to finalize the adjustment functionality. I also need to finalize all the bolts and add cotter pins where appropriate, but before I do that, I want to prime and paint the pedals. I briefly considered having them anodized, but decided that just using the same interior paint as everywhere else will work. It’ll also provide a slight bit of anti-skid roughness – not enough to impede sliding my feet on and off the brakes, but to help keep my feet in position.