April 12, 2007 - Rear Spar Drilling
It's great having the wings attached to the fuselage. 
Before I could drill the rear spars to the fuse, I had to make sure the wings were straight with each other and at the proper incidence.  I hung a plumb bob from the inboard and outboard of each wing and made sure they were aligned along a laser line.  I had to push the outboard edge of each wing aft a little to get the plumb bob all one the line. 
 
Then I cut a piece of particle board to 3" and used it to support a steel angle as shown below.  The angle is supposed to be absolutely horizontal and amazingly enough, the SmartTool showed 0.0 degrees!  I did the same thing at the middle and outboard of the wing.  I guess if the wing had any twist, you SmartTool would tell the tale.  But my wings appear straight, as all the readings were either 0.0 or 0.1. 
And 0.0 on the left wing root. 
I also measured the height of each wing tip -- they were equidistance.  Finally I measured from each wing tip to a point on the aft fuselage.  Equidistance.  Bottom line, the wings are straight and have the proper incidence.  It's time to drill the rear spars. 
 
I had bought this drill jig device some time ago.  You use it to keep your drill bit perpendicular to the work. 
Apparently, it's critical that the center of the hole in the rear spar is at least 5/8" from the edges.  There's very little room to play with; you pretty much have to have the hole in the absolute center of the rear spar area.  I was very careful at this point.  This is one task that you simply have to do right the first time. 
I drilled the right side with my 12" long 1/8" bit, using my drill jig to keep the bit perpendicular. 
Right in the center!  So far, so good.  I did the left side the same way.  The next step is to widen the hole to 5/16".  My electric drill is too big, though, so I'm going to have to come up with another solution.  Either get longer drill bits or use a different drill.
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