This process is much the same as any other process on this project, if you want to do correctly. It involves a lot of measuring, positioning, clamping, leveling, and drilling. Gee that sounds awfully familiar for some reason!
The steps for setting the support angles went something like this:
1. Drill the first support bracket mounting holes on the 2 inch center that was previously marked on each support angle. I am using 1/4 inch hardware for this, so I drilled a 1/4 inch hole. I used a center punch but the drill bit I used still wandered a bit. It is for this very reason that I wanted to drill the holes in the support angles first, instead of drilling the holes in the wing stands. That way I can use the final hole of the bracket to match drill the hole in the wing stand later.
2. Determine the height of each support bracket- I settled for about 48 inches above the floor of each wing stand and made a couple of marks on each stand accordingly
3. Clamp one of the support angles into position. Use a small level to verify that the support bracket on one end is truly level.
4. Determine what the "true" level height should be for the bracket on the other wing stand as follows:
Remember that my garage floor is anything but level, and so simply measuring 48 inches for each stand and clamping both support brackets in place is probably not going to really give me a level-sitting wing spar. Why all this fuss about leveling the wing spars? Simple. Even though the ribs and skins are prepunched for an exact match, once you start clecoeing them to the ribs, gravity will still have a tendency to pull on the entire assembly to the point where you may end up with some slight mismtaching of the skins. Better to ensure everything is truly level so that the skins will want to fall straight down perpendicular to the wing spars, and the ribs will do the same.
To resolve this I used some fishing line and several line levels like the ones shown in the pic below.
With the help of my son we stretched the fish line across the wing stands with the line levels in place to check for true level between the stands. One end was placed directly on top of the clamped support bracket on one side, and the other was stretched across to the other wing stand, and a mark was placed on the short side of the wing stand along the fish line, after verifying that the line levels were truly level.
This is where it gets a bit comical. I knew that I may have to adjust my marks on the stands by perhaps one or two inches, but when we used the yellow line levels to check for level, I mistakenly thought that the bubble needed to be inside the black lines in the middle of the level. This resulted in an offset of about 6 inches from one stand to the other. Really, I need to set one support bracket 6 inches higher than the other one on the othe stand??! Not believing this for a second, I decided to switch to the more normal looking blue line levels, and of course, this time I only need to adjust the marks on the opposite wing stand by about .5 inches. That made a heck of alot more sense. My floor is bad, but not "that" bad!
Then I finally figured out what I did wrong. These yellow levels display several marks that show different offset values from level, so that you can set specific grades for drainage for things like driveways, sidewalks, etc. I should have set the fish line so that the edge of the bubbles on these levels just meets the line marked 0, and the rest of the bubble is on the clear side, opposite the side with the marks. SO whne you want the bubble to show "level" it is not located in the actual center of the level. What a messed up tool! Just goes to show you that no matter how seemingly insignificant a tool is that you might use for your build, you must know how to use them properly, or you may risk really end up screwing something up. I re-measured everything again with the yellow levels just to satisfy my curiosity, and of course the marks ended up being about the same as with the blue line levels. What a relief.
5. I used a square to carry the previous mark around to the inside long edge of the wing stand. This is the line that the support bracket must align with to keep everything level.
6. Then I clamped that bracket into place using two bar clamps on either side of the 1/4 inch hole that I previously drilled. This allows me to use the hole in the bracket as a pilot hole for drilling the first hole in the wing stand. I used some boelube and the cobalt drill bit to match drill the hole for the bolt that will be inserted into the wing stand and support bracket.
And this is where I called it a night. Next step will be to accurately measure the location of the bolt hole on the other side of each wing stand so that it lines up with the holes that I drilled tonight. There are several ways to accomplish this to ensure that the bolt holes are straight across from each other, and I will explore which method I want to use and post more about that tomorrow. I do not trustmyself to keep the drill straight enough to continue drilling the hole on the outside of the stand by using the hole on the inside as a guide. I have very poor luck with free-hand drilling holes like that. They always end up a little off. So I will take my time here and do this right.
Closing with some pics of the work done tonight:
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