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Construction

Elevator Trim Tabs

The final stage of the long elevator trim tab journey ended when we actually rigged the trim tabs. The motor is in the tailcone and attaches to the trim tabs via two cables routed through the horizontal stabilizer.

We then tested to ensure it went up and down the appropriate amount. Done!

Wing root fairings

We did most of the work for the wing root fairings earlier, but we needed to finish drilling holes and installing nutplates on the front side of the wings.  This should (thankfully) be the last set of nutplates we need to install.

Finishing the fuel lines

The last fuel lines we needed to make go between the fuselage and the wings.  In doing that, we noticed our flaring tool was putting gouges in the backside of the flare.  Here’s one of the worst ones.

After taking the rough edges off with a scotchbrite pad (which didn’t completely remove the marks) I showed it to a couple more experienced builders, and they said it should be fine, given the problem is on the outside of the flare and that’s not an area that flexes.  I wanted to be sure, given how critical the fuel system is.

Sorry!

Sorry for the lack of updates.  We’ve been doing a lot of “miscellaneous” work to finish up, some of which we’ll talk about in the next few posts.

Wingtips and final empennage fairing

I put the fiberglass wingtips on the other day, at least with a few screws.  All the lights are connected, too, so it was a great opportunity to test everything out.  I wish I’d taken video, but I verified that all these work:

  • Position lights (red and green LEDs on the wingtips and a white on on the tail)
  • Strobe lights (again, one on each wingtip and one on the tail)
  • Landing lights (one in each tip).  I also verified the pulsing system works–we used this one: http://www.xevision.com/hid_pulsing.html

With the battery and power supply hooked up, I also took the opportunity to test the pitot heat.

We also installed the last of the empennage fairings: the lower rudder fairing.  This one contains the tail/strobe unit, so we had to run the wires back there.  It’s all hooked up now, with a 9-pin D-Sub connector in the fairing.

Merry Christmas!

More Baffle Work

With the cowl mostly done, we could finish the baffle.  All the aluminum pieces are fit to the engine, so now the fun part: getting a 3/8″ to 1/2″ gap between the top of the baffle and the underside of the top cowl.  This involves many, many iterations of putting the cowl on, checking the clearance all around, marking areas, cutting, checking again.  As you can imagine, there’s a lot to check, and with the cowl on, it’s not always the easiest to see.  To help out, Kelly put paperclips all over the baffle.  That way, when we put the cowl on, it would push down the paperclips.  When we took the cowl off, we could then see exactly how far down it went.

We ended up having to cut quite a bit off to get the fit right.  When we were done, I sanded the edges smooth and was very thankful to be done with this part.

The last real step in the baffle is to attach a rubber material to the top.  This closes the gap between the top of the baffles and the top cowl.  The rubber has to be curved in, so the high pressure above the engine doesn’t push the rubber out and flap against the top cowl.  Kelly pretty much did this herself.

Done!

Fitting the cowl

More giant pieces of fiberglass that need to be endlessly cut, sanded, and fitted.  Yay!  The cowl doesn’t seem too bad, but maybe I’m just desensitized after doing the doors and wheel fairings.  Anyway, not too much noteworthy here.  We did need to mount the propeller temporarily to get the cowl fit correctly.

Here we are working on fitting.

Baffling

With the engine mounted, we started working on the baffling, which mounts to the engine and routes the cooling air efficiently around the engine cylinders.  This part wasn’t bad–basically just a bunch of pieces of aluminum, which is a nice break from the fiberglass.  Here are a couple pictures of the aft parts temporarily mounted.

Probably the only really annoying part of the baffling so far is bending the inlet ramps, which go in the front.  Bending a large, relatively thick piece of aluminum isn’t much fun.  Here is a picture of me bending as well as one of the finished product.

im

This is about as much of the baffling we can do for now.  The rest requires the cowl (the large fiberglass pieces that cover the engine) to be fit, so on to that.

More work on the fairings

Long delay since the last post–sorry about that.  We went down to Arizona on vacation, then had family in town, so work has been slower than normal.  We’ve continued to work on the fairings.  The main wheel and leg fairings are done, and we’re close to being finished on the intersection fairings between the two.   The nose wheel fairing is done, too, but we’re still working on the nose leg fairing.  Here I am working on the nose fairing.

Here I am aligning one of the main gear leg fairings.  The strings represent “level”, and they’re wrapped around the leg, so we just needed to make sure the trailing edge was between the strings.

Here’s a quick look at one of the intersection fairings.

One of the last things we did is mark a distance of 5/8″ from the tires for trimming the fairing opening.  When there’s weight on the tires, they’ll spread out, and you don’t want the sides contacting the fairings, so at least 5/8″ clearance is needed.