August 23rd, 2015

Sorry for the lack of updates lately, but this time I have a good excuse: We are moving! Mary got a job offer that promised to be a very positive step for her career, but which also happened to be on the west coast. She took the job, moved out west, and is renting an apartment. Eventually we intend to look for a house in the Pacific time zone, but in the short term the airplane project will have to be moved cross-country and then put into storage for a while. Fortunately, I have a new friend out west who's agreed to allow me to put my airplane in his hangar.

In the meantime, I am still in the midwest packing up everything and getting ready to sell the house. I suppose it's only fitting that I'm the one left behind to do the packing, because – either by weight or by volume – the majority of the stuff in our house is the responsibility of yours truly. This whole process has caused me to realize that I'm a total tool hoarder and a complete packrat for anything mechanical. For instance, these shelves used to be absolutely chock full of tools and airplane parts, but in terms of my total shelf space they only represent ten percent of the total hoard, tops. I still have a lot of work to do, but a whole lot of stuff is already packed away.

I filled up the fuselage with as many bulky-but-lightweight items as I could – carpet, seats, interior panels, fiberglass fairings, etc. I also temporarily reinstalled as many components as possible, to reduce the total number of items that have to be moved. I think this is actually the first time I've had both the canopy and cowling installed at the same time. I have to admit, it looks pretty cool.

To allow it to fit on the truck, I had to remove the horizontal stabilizer from the fuselage. That's just as well, because I don't think it would have fit through the single-bay garage door otherwise, thanks to the annoying post in the middle of the garage. I left the vertical stabilizer attached, in order to help soak up the load from the tailwheel mount. The forward spar of the vertical stabilizer is temporarily secured to the fuselage with a block of wood and some clamps.

I used miniature furniture dollies under the main wheels to allow the fuselage to move sideways and snake its way through the narrow garage door. In this photo you can just see one of them under the left main tire.

Can I count this as the airplane's first grass landing?

After more than a decade of building, I had hoped to be able to fly this airplane soon, and it is in fact really close – but not close enough. So, time to call for the big truck.

The trailer currently in use by Tony Partain's trucking company is pretty neat – all kinds of clever attachment points to tie down airplane parts.

Unfortunately the wing stand wouldn't fit on the truck, so I'll have to donate it to a local builder and figure out something else for the other end.

Here's how the wings are transported. It's all very secure, and it keeps them out of the way of the fuselage as it's rolled inside.

This is the last time I'll see my airplane project for a while. It was a pretty heavy feeling seeing it disappear around the corner. Still, our new living situation should eventually allow me to spend more time working on finishing this project – after a few months to get re-settled, that is.

To be continued…

FWF wiring complete

June 21st, 2015

With the firewall-forward wiring finally complete, I spent the better part of a day bundling wires, attaching adel clamps, and replacing all the temporary tie-wraps with the high-temp variety. Now the FWF wiring is all safely secured, and looks pretty good too if I do say so myself. Here's a collection of photos showing the end result. I lost track of the number of adel clamps I installed today and I'm too tired to describe every one!

I also closed out the two firewall passthroughs. The wire bundle is wrapped in multiple layers of firesleeve and clamped solidly, which should keep the flames on the hot side of the firewall in the event of a bad day. I also applied copious lengths of silicone tape to seal the ends and prevent hydrocarbons from soaking into the fibers. Here's the starboard side:

And here's the one on the port side:

I will probably put some kind of sealant on the inboard side of the firewall passthroughs as further proof against fumes and carbon monoxide, but that can be done later.

Being able to check off a major family of firewall-forward tasks is huge! I'm sure I'll get stuck and frustrated again soon enough, but for now it's a great feeling to be able to call the FWF wiring done.

Ground power plug

June 21st, 2015

The last remaining wiring task forward of the firewall is some kind of power connection for use on the ground. There are two schools of thought on how this ought to be done – at minimum, a ground power connection should be capable of charging the aircraft battery and perhaps powering the important avionics during maintenance, but some folks also like to be able to jump-start their airplane from a power cart in the event of a dead battery. The problem I found with the latter approach is that the connector required to support starter cranking current is expensive and huge, and there's not a great place to mount it without cutting into important fuselage structure. I also decided that in my electrically-dependent airplane, it wouldn't be wise to get a jump-start and then immediately go flying with a sick battery. So, my ground power circuit will be capable of connecting a battery charger or a small power supply to run the avionics, but to save weight and complexity it won't be able to crank the engine.

For the ground power connection I needed a connector that's lightweight and rugged but still able to handle plenty of current. I selected an Anderson Powerpole connector, which is widely used in the amateur radio field for high-current applications. These connectors are kind of cool, in that multiple poles lock together in with dovetails in a variety of orientations, allowing you to create any kind of custom connector you want. For this application, though, I stuck with the de facto standard arrangement.

Of course, what's a new connector without a new crimper to go with it? I couldn't figure out how to buy just the dies for these connectors, at least not ones that would fit any of my existing crimper frames, so I ended up with a whole new crimper just for a couple connections. Oh well, as a tool junkie I can't complain too loudly.

The ground power connector is secured near the oil dipstick, so that it will be possible to access it through the oil door without removing the cowl. The wiring is 12-gauge, which will be good for up to 15 amps. The black side of the connector finds its way to the main ground block, and the red side connects to the always-hot battery bus through a 15-amp fuse.

Another closeup view… The wiring is tied off and clamped in such a way that nothing can flop around and abrade itself or anything nearby. I left a decent service loop in case I decide I need to relocate the connector later on.

I fabricated a short Powerpole harness for my bench power supply, plus a ten-foot extension cord with Powerpole connectors on both ends. I plugged it all in and verified it works to power up the panel, so that's that. I'm sure this will get a lot of use, both during construction and afterwards.

Another breather hose

June 13th, 2015

So, this was the previous arrangement for the engine breather hose… a 90-degree AN swivel fitting plus a 90-degree hose end:

I was driven to use this setup – which let's face it, was overcomplicated at best – by the limited options for hose routing that are available when you have an angled oil filter adapter, as my engine does. There's practically no good way to point the hose fitting that doesn't cause either the fitting or the hose to hit something else. But then I had a brain wave and thought of a much simpler solution, so I tore out the existing hose and engine fitting:

This is the new arrangement I came up with. The fitting on the engine is now a 45-degree brass hose barb, pointed towards the left side of the engine as well as somewhat forward. This allows the hose to clear the engine mount heading forward, whereupon it takes a medium-sharpish bend and turns 180 degrees back towards and air/oil separator. It does come close to the baffles and the oil cooler plumbing, but there's plenty of room for things to move around without rubbing together.

The hose is affixed to an engine mount tube with a pair of adel clamps, the purpose of which are to pull it down and keep it from rubbing on the inside of the top cowl, which is its natural tendency due to the angles involved. Although it seems at first glance like there isn't enough slack in the hose to accommodate movement of the engine, in actuality there's at least a foot of hose there, with a pretty good loop in it. This MIL-6000 hose is also fairly springy, and you can "boing" it back and forth an inch or two with your fingers. Compared to the fuel hose on the bottom of the engine, there's actually more slack in the new breather hose.

Here's another view, looking across from the right side of the engine. The engine mount and oil separator do not move relative to one another, so the short length of hose between the engine mount and firewall doesn't require any slack in it.

I have now re-engineered every piece of the breather system at least twice! I think it's truly all finished now. Here's hoping, anyway.

Thermocouple heat shields

June 13th, 2015

Even though the thermocouple connectors are made of fairly high-temperature nylon, I didn't like how they were only a couple inches from the hottest part of the exhaust pipes. So, I bolted on a couple more radiant heat shields. Here's the left side:

And the right side: