Fitting the Flaps

4 July 06 - Fitting the Flaps

After some puttering and planning over the last few days, we've actually got what is hopefully a fairly comprehensive list of things that need to happen before we get the wings off. This is rapidly becoming the most important immediate goal, given how much of pain in the rear it is to try to get around the shop. The first thing is to get the wing tank attach brackets match drilled. This would be fairly straightforward, however, we need to bend them so they're a nice close fit.

Fortunately, the brackets can be removed from the fuselage without having to take the wings back off, so there was a bit of take it off, whack it with the hammer, and put it back on, and then repeat the entire process sort of stuff here. I think that leaving these unbent until you have the wings on is a good idea - it's difficult to guess what the bend will need to be before the wings are on there.

Here it is being clamped. I used a right angle drill to drill this from the back, so we would have a way to line it up with the bracket that's on the back.	After drilling. These are both of the right wing, however, both wings have been done.
The actual motor hasn't been in the plane recently, so it's time to get that in there and (just temporarily) wire it up.	Preliminary fitting of the flaps showed us that the right one ran into the fuselage - there's supposed to be something like 1/8" of clearance in there. This is the line to trim it.
Worth pausing here to say - I've seen some discussion on a few RV lists of folks that want to make the edge of the flap closer to the fuselage, which I think is a Really Bad Idea, with capital letters and everything. The way the flap is shaped, when you have it up, you have to have the recommended clearance there - the front part will get closer to the fuselage when you put he flap down, and if you don't have enough space in there, it'll rub the fuselage and the edge of the flap will scratch it. (Ask me how I know this.) Actually, this isn't really a big deal, but if you were fitting these after painting it, I can see how you'd be pretty unhappy with that result.
Fit after trimming. Looks good!	Starting to work on the hole for the flap rod - view from the inside shows how the rod end bearing has to fit through the hole. (See below.)
The rest of the day was spent working on the holes for the flap rod. It's worth finding another RV and looking at what this hole is supposed to look like, because it's pretty weird. The whole is generally larger than you think it needs to be, and fortunately, it is completely covered by the flap when the flap is retracted. Quite a bit of this is just trial and error - you're trying to get something that's as small as possible without anything rubbing. It's also worth noting that the rod end bearing is pulled more or less completely inside the fuselage when the flap is retracted, which explains the sort of odd shape to the hole, and why it has to be as large as it is.
Here are a few more pictures of the weird-shaped hole from various angles.	Hopefully, these will help someone.
Flap fully retracted. Nice fit.

And that's how we're leaving it for today: the right side is mostly done, however, the flaps can't go down more than about 25 or 30 degrees before the rod end bearing rubs on the front side of the hole on the bottom of the skin. That needs to be extended a little bit, and then that same hole needs to be copied to the other side.

I'm expecting that we'll take this one pretty slow, but the next one should go more quickly as we'll have a better idea what it's supposed to look like.

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