Even though there is work left to do on the wings, I was excited to get started on the fuselage. First up is to fabricate the firewall. There are several parts that have to be fabricated from rough stock. These are fabricated from some beefy 0.187″ thick angle stock.
I was up until 3 AM finishing the fuselage inventory. I found the two parts I thought I was missing. I only found one mistake where Van’s sent me some of the wrong kind of screws. I’ll give them a call on Monday to get this corrected.
I still need to reorganize my storage bins to get everything put away, but that can wait until tomorrow; I’m beat.
My fuselage kit showed up today. I wasn’t home when the driver showed up, but Jenn opened the garage door and the driver placed the kit inside.
My fuselage was scheduled to ship next week some time, but on a fluke I checked my credit card online today and noticed I had been charged for the fuselage. I called Van’s to see if I could get an estimate on when it would ship and was told it had shipped yesterday. I called FedEx freight and they told me that it will be here tomorrow! Holy lack of notice Batman! If I hadn’t checked, I wonder when I would have found out.
I didn’t do any work on the plane tonight, but I did spend a couple of hours cleaning up the garage and making room for the fuselage crate. The crate is pretty big (about 8′ long, 3.5′ wide and 1.5′ thick and it weighs over 300 lbs), so once I get it into the garage, I still need room to get around it and unpack it.
I got up this morning and drilled the left flap before work. This side didn’t end up quite as good as the right side (the flap trailing edge ended up about 1/64″ below the aileron trailing edge as it’s standing vertically like this). I looked around at a bunch of builders websites and this is apparently a really common problem and 1/64″ is actually better than most. I don’t think I’m going to replace the hinge since it could easily end up worse. I may be able to tweak a few things to make it just about disappear when finally riveted together.
Van’s offers a couple of suggestions for securing the flap hinge pin. The first is to drill a hole in the inboard aileron bracket that’s intentionally slightly out of alignment with the hinge pin. The hinge pin is then inserted through this hole and the misalignment prevents the pin from sliding back out. The other suggestion (which most builders including me go with) is to remove several of the hinge loops near the center of the hinge and then secure the hinge pins against the flap brace. Here I’ve removed one loop on the flap side and two on the wing side. You can also see here how close the rivet holes ended up to my line drawn at 1/4″ from the lower edge.
I drilled the flap brace for the #8 nutplate and riveted it on with a couple of oops rivets.
Here you can see how the hinge pins are secured. The bends in the hinge pins prevent the pins from migrating toward the ends of the flaps and interfering with either the ailerons or the fuselage. The clip (which I made by cutting a couple of loops off of some extra hinge material) will keep the hinge pin from migrating inboard. I’ll cut off the extra pin material that’s sticking out beyond the clip the next time I have the flap off of the wing.
After triple checking all of the measurements, I drilled the flap hinge to the wing. I ended up using the P3 hinge that ships with the kit, and I’m well over the minimum 3/16″ edge clearance for AD3 rivets (I’m less than 1/32″ beyond the recommended 1/4″ edge clearance).
Here’s a shot of the whole wing. The control surfaces add considerable area to the wings.
The first step in rigging the ailerons is to place the aileron alignment bracket over the bellcrank with a bolt through it and the rear aileron push tube’s end bearing.
I don’t think I can just squeeze the flap trailing edge either since the flap skins nicely follow the angle defined by the end ribs. If I squeeze the trailing edge, the skin will have to bend inward as it crosses the trailing edge of the end ribs. I’m going to see if anyone on vansairforce.net has any ideas.
Update: It turns out that the scale drawings on the flap and aileron plan pages clearly show that the flaps and ailerons have different trailing edge radii, so I’m not going to do anything about this.
After dropping the kids off the morning, I stopped back by the house and riveted on the flap braces. I’m definitely getting the hang of riveting with the gun solo. I slightly overdrove a couple of rivets (though not badly enough to drill out), but virtually all were perfect.
After work tonight, my wife was hosting a Bunco party at our house, so I was on kid duty. After they went to bed, I had a little time before the ladies left, so I snuck out to the garage and mounted the other aileron.
I also safety wired the autopilot roll servo’s mounting bolts. I’m still getting the hang of safety wiring. It’s tricky to estimate how much extra wire to leave before twisting since the wire segment shortens as you twist it. It only took two tries to get this properly secured.
I installed the aileron braces tonight. All of these rivets could be squeezed, so I could do this after the kids went to bed without making too much noise.
Here is a closeup of the outboard part of the flap brace. The relief cut on the left allows the brace to step up onto the rear spar doubler, and the complicated shape on the right allows it to follow the outboard aileron hinge bracket closely. The brace is riveted onto the rear spar with universal rivets, but is riveted to the top skin with AN426AD3-3 rivets which are the shortest rivets I’ve had to use on the project so far (and I assume the shortest I will have to use). I assume these rivets are so short so that there is clearance here for the aileron.
I also clecoed on the flap brace, but couldn’t rivet it on because these will have to be shot and bucked since the brace blocks access with the squeezer.
I assembled the rear pushrods. The jam nuts are not torqued down yet since I will have to adjust these to final length once they’re installed.
I went ahead and loosely installed the left aileron on the wing. None of the bolts are tightened down since this may have to come back off at some point.
Here is a closeup of how the pushrod comes through the rear spar. It’s clear now why the hole is oddly shaped as the pushrod traces a curved arc as the aileron is swung through full travel. I verified with the digital level that the aileron can exceed the maximum allowable up/down travel. I still need to fabricate the aileron stop that will limit the travel to the recommended amount.
Here is how the pushrod attaches to the bellcrank. Again, nothing is torqued down until I know that it’s on for good.
I think tonight will be the last priming session for the wing. I mixed up some epoxy primer and injected a few ccs into each aileron push tube through the hole that the welder drilled to relieve pressure during welding. I then swirled the tubes around to coat the entire inside with the primer.
I then primed the outside of the tube except for the threaded ends.
I then primed the back side of the flap and aileron braces.
And finally, I primed the parts of the rear spars and skins that will be covered up by the braces.