Tuesday, January 19, 2010

While we're waiting

I'm having withdrawal pains as I impatiently await the arrival of the fuselage kit. I've read through as many revision pages concerning the fuselage as I can find on Van's web site, but there just aren't that many.

I did find it amusing to find a page that boldly called out the need for a 120 degree counter sink bit when using a flush blind rivet, the omission of which frustrated me so greatly when it was not called out during the building up of the horizontal stab's spar box. In cases like this, it is important to remember that the tail kit was one of the last to be released by Van's, at least with regards to the airframe kits. With that in mind, it becomes more understandable why Van's didn't see the need to tell us; the early builders had already learned when to use the 120 degree bit in earlier kits. These days, though, when new builders are selecting the tail kit as the traditional starting point, it would seem to be a good idea for Van's to circle back and take a fresh look at the plans for the empennage.

There were still a few parts sitting on the parts shelf, so I thought I'd go ahead and build the tray that will hold the electric trim motor. There are a few pieces that go through the remove plastic covering/separate/deburr ritual. There are also a couple of lengths of aluminum tube to be cut to a very specific length, presumably to be used as spacers somewhere. This was another step where the band saw was far superior to the hack saw. I did find it odd to see one of the lengths listed as 28/32" rather than 7/8", but it could be the case that presenting the measurement in 32nds rather than 8ths is Van's code for "don't be sloppy with the measurement."

The assembly of the tray is pretty straight forward, but I did notice that for the first time the plans dictate a preference for which way a blind rivet gets installed. They state that the manufactured head should be on the inside of the tray (or MFR. HEAD THIS SIDE, to use their lingo) most likely for reasons of clearance that will become apparent later. In any event, it makes for a tight fit with the rivet puller:

It can be done, though:

The brackets to hold the motor in place are clecoed in and match drilled through the four existing holes and two brand spanking new ones:

There are six truss head bolts and some itty-bitty little lock nuts that hold the brackets in place. The lock nuts are far smaller than any reasonably sized wrench or socket, so I was at a bit of a loss as to how to hold them while screwing the bolts through. Being lock nuts, it was a very tight fit. I finally just put them in my drill vise to hold them:

I imagine that's a rather unconventional method, but it worked just fine.

There's an arm that will attach somewhere downstream of the trim motor. It has to have a bushing pushed through it, and I did that using the same vise/socket methodology I used back when I was doing the aft bulkhead on page 10-04. The same method was used to push bushings into the pivot points on the tray:

At that point I ran into a pretty confusing drawing having to do with filing down the plastic bushings to a minimum or maximum size. Oddly enough, the confusion over the drawing was enough to temporarily ease my withdrawal pains quite adequately, thank you very much, although I'm not sure the ensuing headache was a good trade. It was a good time to stop anyway since the next few steps call for the use of the wire stripper and the wire crimper that I keep out in the hangar.

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