October 5, 2007

Prepared Z-brackets - 7 hrs.

Today I prepared the z-brackets for the tank. It's more work than meets the eye. It involves some careful measuring and marking, drilling holes, and riveting nutplates on. Then, they were bolted to the spar and the tank was fitted to the wing for the first time.

Here are the z-brackets, all deburred and polished up, ready to go. For the sake of maximum efficiency, I have tried, whenever it's possible, to finish parts like this for both wings when I'm working on something. After all, you've invested the time and energy to think... to figure out how something needs to be done. And you're in the mode of doing it. The tools and/or equipment or set-up for the task has been lined up and you're ready to go. You've studied the drawings and read the plans. All of that is an investment of your time. So once you're all set up to do something, why not put in just a little more time to do it for both wings? It's much more efficient that way and you won't have to re-think or repeat or re set up tools and stuff for the next time. I know the next wing will go a lot faster because I already have the skeleton riveted together, for instance. The tank stiffeners for both tanks have been cut out and deburred. And as you see above, the z-brackets for both tanks are deburred and polished up, and marked for the holes. There are a lot of little things like this that I have done along the way to make the next one faster and easier.

So why not build both wings at once and really do it right? Well, a lot of builders have done that. But for me, it won't work because I don't have the room in my shop to have both wings on the jig at the same time. I don't have enough clecos either.

Next, holes are drilled in the z-brackets for the nutplates that are installed. I'm doing the Dan Checkoway method on these z-brackets and tanks, abandoning the plans for this part of the project. So these drill lines are offset just a bit from center, as he describes. Above, I'm using a piece of scrap wood to drill into, and I have a nutplate clecoed on, ready to rivet in place.

The platenuts for the innermost z-bracket are riveted to the wing spar. Here, you can see the countersunk holes for the nutplate to the left of my little tungsten bucking bar, and one nutplate already riveted in place to the immediate right. By the way, this bucking bar is great! I'm glad I spent the money on it. I probably won't use any of the others from this point on. I have some duct tape on it to prevent scratching when I use it.

Here's a shot from underneath the spar, looking up at the 3 nutplates for the inboard z-bracket.

There are seven z-brackets that hold the tank on the wing. Six of them, shown above, have nutplates installed. These are all finished, ready to go. I'm showing 3 from the top view, 3 from the bottom. They're all the same. The 7th one, not seen here, is the one bolted to the nutplates shown above on the wing spar. At this point, they are bolted to the spar, and then the tank is clecoed in place above them for drilling.

Here are a couple shots of the tank, clecoed in place on the wing for the first time. Wow! Seeing the whole wing together for the first time is quite a thrill!

The idea of Dan's method is to make sure this joint is as tight as possible, with no errors. This is where the tank meets the leading edge. It's a bit confusing to tell because I haven't removed any vinyl from the tank skin yet, but you can see how tight-fitting this joint is. Perfect!

The bottom of the wing shown above. Sure looks great.

The top of the wing looks even better. Wow! But now that it's fitted precisely in place, it's time to start taking it all apart and drilling holes in the z-brackets.

First, the inboard end rib is drilled through the baffle and z-bracket. It takes 9 copper-colored clecos to finish the job.

That's all for this session. I feel like I got a lot accomplished today.

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