Even though the oil cooler is pretty solid with the added aluminum angle I put on the corner of the baffle, people tend to recommend still adding additional stiffness to the whole setup to keep the baffle from cracking. One common approach is to add some sort of a brace from the inside edge of the cooler over to a rocker cover screw to essentially create a rigid triangle. I had some leftover steel tubing from when I made my exhaust pipe hangers, so I decided to use that to create the brace. I tried and failed 3 times - that tubing was just too thick to get bent at the exact angles needed (not only bent to go from the cooler out to the rocker cover screw, but also bent at a second angle to drop down vertically as well). I finally gave up and ordered some steel tubing of the same size but half the wall thickness. Still plenty strong, and bending was much easier. With that in place, I think the cooler is rock solid to the shaking baffle, and the baffle is solid to the shaking cylinder. Hopefully that means no baffle cracks.
With Dad here, we started to tackle all of the random work that is a little easier with a second set of hands. The first up were the leading edge lights on the wings. We reorganized the shop and pulled each wing out of the stand to lay them down so we could do the crazy part - cutting holes in perfectly good wings! I didn't get pictures of the process, but after scratching our heads over the instructions (not Van's) to make sure we 100% knew where to cut the hole, we used a template and went to work. Other than being a bit nerve wracking, it was relatively easy and uneventful. Then we chopped down the install bracket to fit between the ribs of the last wing bay, drilled holes and installed nutplates for the mounting screws. The brackets were painted black to help them disappear in the cavity a little better. Then, using the wing cutout as a guide, we trimmed the lenses that get inserted and are held in place with nutplates and screws. The lights themselves just drop into the bracket and are attached with screws. Once the wings are on the plane, I'll have to aim the lights - the bracket has oversized mounting holes, so can be tilted up and down just by loosening the screws. I'm leaving the lenses off until after I paint.
Next up was the part I'd been dreading - getting the forward top skin riveted on. This is the last major item to rivet on the entire plane, and probably also the most awkward. We pulled the canopy off, and after double checking all of the wiring to make sure there wasn't anything else I needed to do before my access to behind the subpanel was covered up, we got to work riveting. Well, that was after we fought with the top skin just to get it in place. We ended up having to use ratchet straps to pull in it down tight to get the longeron clecos in.
I laid underneath the panel (bent backwards over the spar carry through - super comfortable!) and bucked rivets while Dad used the rivet gun. It took a good chunk of the day, but we got it done! There were a few rivets that were just impossible for me to reach due to where I had mounted some of the electronics boxes, so I ended up using a couple of pop rivets in those locations.
I reinstalled the canopy pin mechanism (I had to take it out earlier in order to buck the rivets along the center subpanel), and we reinstalled the canopy. I can't say that I look forward to taking the canopy off and on very often! That might have been the most stressful part of the entire build so far. It's very difficult to get the hinges to line up with the pins, all the while trying to hold the canopy in position so you don't snag the leading edge skin on the fuselage. I've read horror stories of people creasing that canopy frame skin and essentially having to rebuild the canopy frame to fix it. We did manage to get it back on without any damage.
I will still have to crawl back under the panel at some point to put proseal in the gaps of the subpanel to waterproof the seam. I need to wait for my back to return to a normal shape before I try contorting under the panel again though. I didn't get a picture, but we also fit some weather stripping to the underside of the canopy frame where it sets on the fuselage canopy rail.
Switching gears, we moved back up to the firewall forward stuff. We spent a while just staring at things trying to sort out the last bit of fuel hose routing I need to do. The area is getting so full of stuff that there really isn't a perfect routing to take, but I think we landed on the best option. We took measurements and I shot them off to the guy who I use to make hoses. I ordered the fuel hose that goes from the firewall to the mechanical pump, then one from the outlet of the pump to the fuel totalizer, and from the totalizer over to the fuel servo. I'll get those hoses next week sometime. Fingers crossed they're the right length.
The hose that Titan installs for the fuel servo up to the distribution spider took some thinking too. It's the perfect length for their setup of course, but I'm using crossover exhaust, which while it's fairly standard in the RV world, isn't the normal straight pipes option that is on most engines. What that means is that Titan's planned routing for the fuel line takes it right between the sump and one of the crossover pipes. There's clearance, but we're talking like 1/4". I don't know that I could insulate that well enough to not have some heat issues with the fuel. What we landed on instead was routing the fuel line over the front air intake pipe and down in front of the rear one. I'll need to come up with a way to adel clamp it to the rear intake pipe.
Next up is the air intake box that hangs below the fuel servo. The FAB, as it's called, is a fiberglass scoop with a couple of aluminum plates. As simple as it looks, it took the better part of a day to get it "finished" (not finished). The top plate is put in place to be able to apply just enough squish of the air filter to keep it in place. One of the issues I've seen over the years is that the K&N filter tends to shrink over time. When it does that, it no longer stays squished between the top plate and the fiberglass bottom of the FAB. Then it starts to vibrate with the engine and eats its way through the fiberglass. From what I've gathered, as long as you watch out for that and replace the filter before it shrinks too far, everything is fine.
Part of the fiddly nature of getting the FAB set up was getting it lined up with the cowl scoop. Since the engine is angled and not pointing directly ahead (offset thrust for a host of aerodynamic reasons), the FAB has to be angled back to center to meet up with the cowl center line. We first bent the top plate of the FAB up to match up to the top edge of the scoop, then did a lot of back and forth to get it centered laterally. It's still not perfect because of the poorly shaped fiberglass, but it's close enough that I'll be able to match it up when I do the finish fiberglass work. I have to mold a fiberglass extension to the scoop to bring it aft a few inches and mate up with the baffle material that will be attached to the front of the FAB intake.
Moving on from the engine, we went back to the wings. The wing tips also get lights in them, although these are position/nav lights, not the landing lights that are in the wing leading edges. I built these lights from a kit a long time ago. They are LEDs attached to circuit boards that will set in the wing tips and get covered by a lens. The circuit boards have resistors and other bits on the back side, so the wing tips need to have cutouts. We used the provided template and made the cuts. The circuit boards can be installed using screws, but the company says double stick tape works just as well. So that's what I'm going to go with - got some heavy duty automotive body trim tape.
The "lens" that goes over the area comes as one big piece for both wing tips. It has to be cut down to size. That was an iterative process, not wanting to take too much off by accident. The fiberglass is pretty sorry, making the fit a little harder. I'll have to do some clean up when I work on the wing tips. One nutplate and screw on the top and bottom corners will be all that is needed to hold the lens in place.
We needed something fun, so decided to go ahead and get the interior fit and mounted too! While a lot of the interior just uses velcro strips stuck to the skins, there are a few screws necessary, so I figured we might as well do it now and ensure it fits before I start doing all of the final finish work. We started with the glare shield trim. I had already drilled the holes for the screws a while back using the template the company provided. Lo and behold, all holes matched up with the trim except the outermost ones on each side. It looks like they may have sent the wrong template or something. I'm going to have to remove the trim and locate where the holes are supposed to be. It's a little irritating to have extra holes sitting in my new glare shield, but I can probably just 3D print a tiny black plug to cover them up.
The rest of the interior install went very well (minus me managing to break my pop riveter while installing a rivnut).The fit is pretty amazing and the quality is great. The only thing not shown in the pictures is the front and baggage area carpet and seats. Once we verified it all fits, we pulled it back and out so I don't accidentally get paint on it when I'm spraying the fuselage.
