Happy Father’s Day everybody!

I spent most of the day with family and some friends, but had a little chance to get out into the garage late tonight.  First up, I marked and cutout the notches in the outboard forward spar cover attach angles.

Next, I decided to try and bend the fuel lines that come in from the sides of the fuselage and connect to the fuel selector.  I knew I shouldn’t have started something like this at 11:30 at night.  I got the first piece mostly bent, then realized that I put one of the lines on the wrong mark on the bender and left one leg too long.  Attempting to fix it only fucked up the tube enough that I couldn’t get a sleeve to slide over it anymore.  I then took the only remaining piece of tubing I had and tried again.  After carefully measuring the bends, I proceeded to put one of the lines on the wrong god dammed mark on the bender again and left a different leg too long.  Holy fucking christ!  I was pretty pissed off by now.  I’m out of tubing and it’s expensive as shit to ship these 6′ long pieces from Aircraft Spruce.  I don’t want to order just one piece either, because what’s the chance that I’ll bend the next two perfectly.  So this was probably a $50 fuck up tonight just because I was not thinking clearly.  I’m going to bed…

I called Bonaco this morning and put in an order for a few hoses.  I ordered a short hose that will run from the fuel bulkhead on the firewall to the inlet of the engine driven pump.  I also ordered the hose that run from the outlet of the engine driven pump to the fuel servo.  This hose needed 45º fittings on each end with 270º clocking.  We’ll see soon if I measured correctly.  I also picked up the hoses that run from the brake fluid reservoir down to the master cylinders.  Since all of my other brake components are black, I had Brett do these in black as well.  Finally, I ordered the brake lines that go from the bulkhead fittings on the firewall down to the wheel cylinders.  Van’s plans call for rigid lines from the bulkheads down to the wheel cylinders with generous service loops inside the wheel pants to allow for flex and vibration.  This is a notorious source of cracking though due to flex in the aluminum line.  Since aluminum doesn’t have a fatigue limit, even minor flexing will eventually result in failure.  Even the MIL-PRF-83282D brake fluid (which is a huge improvement over the old MIL-H-5606 fluid) is flammable, so a brake line failure can really ruin your day.  Some people run rigid tubing down the leg and transition to flex line near the wheel cylinder, but the whole gear leg flexes when on the ground, so this really doesn’t eliminate the line flex.

Since I’m waiting on an order from Aircraft Spruce for new 5052 brake lines, I decided to get started on the cabin frame.  I clamped a straight edge to the bench and then clamped wooden blocks to the vertical legs to define the overall width of the frame.

The center seam was pretty close, but I touched it up with the vixen file to get the edges perfectly aligned.

The bottom edges were not even close to parallel with the guide angle, so I marked and trimmed them flush.

Here is the result.  It looks like there is a shadow here, but that’s just the black line I drew parallel with the guide angle.

The canopy frame is about 1/16″ taller than the plans specify, but I’m going to leave this.  In fact, I’ll likely try to cheat the canopy up another 1/4″ or more in final fitting.  This will directly translate to more headroom in the plane which I’ve heard is a problem for someone my size.

Last up tonight, I drilled the 1.5″ holes in the bottom end of the aft members the roll bar.  This is to allow access to the bolts that hold the cabin frame down to the seat back support.

 

I rounded over the edges of the canopy frame joint strips.  These join the front and back halves of the cabin frame.  The radius is necessary so that the halves can be pulled tightly together.

I also put a strip of masking tape around the inside edge and marked for the lowest hole.  I’ll use a rivet fan to lay out holes along this strip and then use it to drill the holes evenly along the inside edge of the canopy frame.

I didn’t have much time to work on the plane today, but I did manage to get the inner cabin frame joint strip drilled to the aft channel.  I’m only drilling these out to #40 now, but they’ll get drilled out to #30 once everything is fit.

My buddy Andre came over today to help me rivet the aft top skin.  I got the honors of crawling into the tailcone to buck these rivets.  I’m a pretty big guy (6’4″ and 235 lbs), so this was a pretty tight fit and I was pretty uncomfortable by the end.  After knocking out all of the riveting, I also torqued and sealed the shoulder harness attach strap bolts.  I didn’t want to have to climb back in here again if I could help it.

Here’s the finished product. The forward row of holes (where the clecos are still present) is left open since the forward skin also attaches here.

Later in the evening after everyone else had gone to bed, I drilled the outer cabin frame joint strip drilled to the aft channel.  I need to make some spacers to temporarily fit between the forward and aft channels to ensure proper spacing.

I fit the forward channels and filed the ends to ensure the center seam was tight.

I then transferred the lower hole locations to the upper channels.

I then fabricated some spacers out of scrap 2x2s that were sanded down to 1.375″ thick.  Since I’m fabricating the cabin frame flat on my bench, I used some scrap 1x2s and long screws to clamp the cabin frame down tight to the bench.

Here’s a closeup showing how the scrap wood is screwed directly to the bench.  These are positioned directly over the internal spacers.  This keeps the cabin frame thickness exactly 1.5″.

Finally, the top channel was drilled.

I then positioned the forward splice place and match drilled the channels to it.  This will eventually be installed on the inside of the channel.

Now that everything was positioned and drilled, I went back through and enlarged all holes to #30.

While I was doing that, Andre stopped by and fabricated a number of the attach angles.  These are used to attach the cabin frame to the fuselage.

I disassembled and deburred all of the channel holes in the cabin frame.  I then started working on countersinking all of the necessary holes.  These are the ones in the channels that are used to rivet on the splice plates.

I also did all of the outer holes along the forward channels.  These are a little trickier since the curve prevents using the countersink cage to set the depth.  Basically, these all need to be done freehand which makes these holes fairly time consuming.