Wednesday, July 27, 2011

The elephant man


There was a time in airplane homebuilding when the finished product had its share of warts and flaws that stood out like a sore thumb. The goal was the challenge of building an airplane that flew. I wish I'd built an airplane in those days because I'm not sure this one fits me. As N614EF nears completion, I'm embarrassed for other builders to see it.

This era is about building flawless airplanes worthy of Oshkosh; functionality is important, but the lovely finished product is a statement about the builder. Sure, there are dings here and there, but nothing serious and certainly nothing embarrassing.

N614EF's nickname is Auntie Marge, named after a wonderful relative of my wife's who was all about enjoying life. After this evening, I'm thinking of changing it to Elephant Man.

Years ago, when I was originally fitting the frame upon which the canopy would sit, I misdrilled a hole -- one stinking hole -- that allows one side of the canopy to sit slightly higher than the other.

Note, for example, the spot at which the canopy meets the front skin. The skin is sticking up about 1/4" and will, no doubt, act like an air scoop (click any of these pictures for the full monty).



Which creates this gap you can throw a cat through on the side...


Oh, it gets worse. This is a tip-up canopy and when it lifts up, the skin at the base of the canopy moves slightly forward and if a shim isn't put under the canopy frame to raise the skin slightly, it catches on the the skin in front of the canopy. Guess who forgot to put the shim in when riveting the canopy skin to the canopy frame?

So when the canopy lifted up, it caught on the front skin and cracked the fiberglass fairing. The only way to solve the problem is to file away the skin so that it doesn't catch. Doing that creates one heck of a gap. Keep in mind the company says the gap should be 3/32" inch here. This is about a half inch. Functional? Sure. Embarrassing? Yeah.


Normally, it should look something like this:


Another RV builder stopped by the hangar tonight. "I'd redo it," he said.

Allow me to translate that from the polite Midwestern lingo. "You suck at this."

Which, of course, I already knew, but it made clear that for as long as I hang around other people who build airplanes, I'll be apologizing for this one.

And, by the way, starting over would require a $1,200 canopy, and a few hundred dollars for a new canopy frame. I can't do it; I work for a living.

"Are you still thinking of selling this?" he said.

I am, but his message was clear; nobody will pay much to buy it.

All of this, of course, is -- in the lingo of Van's Aircraft, "gumption robbing."

Those thoughts I've had this week about flying N614EF to Oshkosh next year? Yeah, let's stop those.

Perhaps I should have built a time machine.

Greg Poe

Airshow performer Greg Poe died this week of a heart attack in Idaho. He used aviation to spread a motivational message to kids.

Friday, July 22, 2011

Feel-good aerobatics

I've never had a desire to do aerobatics when -- or if -- the RV-7A is finished. I wouldn't know how to do an aileron roll even if I had. SlickHutto on YouTube is the guy who makes those fabulous post-Oshkosh videos each year and he can make any activity look inviting.

Here's his latest video, the soundtrack of which uses my favorite song from one of my favorite -- and long dead -- TV series: Eli Stone. The guy just knows how to make everything perfect in his videos.

Monday, July 11, 2011

Magneto mysteries

I'm completely flummoxed by the wiring of the one magneto in my RV-7A and maybe you can offer some advice.

I have one Lightspeed electronic ignition in the RV, and one magneto. I'm not using the fancy and pricey rotary switch that is so common on airplanes; I'm using a simple toggle switch to activate the Lightspeed, and one to activate the magneto.

The Lightspeed wiring was pretty simple: run a wire to from the Lightspeed control box to a switch, wire through a pullable 5 amp circuit breaker to battery power.

The magneto is a little bit different. It doesn't use ship power, of course. It generates its own power and, thus, spark. Simple.

I've read Bob Nuckoll's discussion of the magneto; I'm not understanding its application.

Here's how I have it wired. Tell me where I went wrong. I made a so-called P-lead, which uses a single connector shielded cable. The conductor wire attaches to a post on the magneto. The shield is pigtailed to an 18g wire, which attaches to a ground stud. I used the construction practices as specified here, except that I soldered a wire to the shield, rather than crimp a connector onto the shield. I figured it would be more durable.



And so, here's how it looks on my magneto. You can click the image for a larger version:



My understanding is that when the magneto is grounded, it is, basically, off and when it is not grounded, it is on and capable of providing electrical power to the spark plugs.

I was under the impression that it is grounded when there is connectivity between the two posts/wires. The problem is from what I can tell there is always connectivity between the two posts and, subsequently, wires; at least there is when I measure it.

I ran this wire to a toggle switch on the instrument panel, figuring that providing connectivity between the two wires "grounds" the magneto, rendering it inoperative.

Here's the wires at the toggle switch:


So, under my theory, flipping the toggle switch upside down, the "down" position establishes a connection between the two wires which grounds the magneto, making it inoperative.

But because the two wires appear to be always with connectivity, because there's continuity between the two posts as I measure it, this would appear to make the switch itself irrelevant, which means I've done something wrong in my theory of how this works.

The problem is, of course, I don't know what it is.

Sunday, July 10, 2011

Paintjob of the year

We were out at KSGS (South St. Paul, Minn.) the other day when we stumbled across this beast.


Apparently, it's owned by the Kodiak company.

Sunday, July 3, 2011

Spinner

I'm still on track for an engine start this summer, and one of the critical components I wanted to get done is the spinner.

You know what? The spinner is sexy.