December 4, 2005 - Longerons
With the center fuselage complete, there was no putting off the "dreaded bending of the main longerons".  The longerons are made up of aluminum angle stock and run the entire length of the fuselage.  The fuselage curves, so the longerons have to curve.  And to get them to curve, you literally have to beat them with a rubber hammer. 

First I measured the beginning and ending of the curved area. 

I followed the instructions exactly.  I secure the angle into the vise, bend the angle with my hand to put a "pre-load stress" on it, then whack it with the rubber hammer.  Repeat every inch in the curved area -- roughly 39 inches from the forward end, to 69 inches from the forward end.  Unfortunately, bending the angle horizontally caused it to bend vertically as well.  The instructions say to rotate the angle 90degrees in the vise and bend it back by hand. 
 
I did all of the above, many, many times.  I finally got the thing banged into shape so that it matched the paper template provided. 
This is a shot of the left longeron, laying on the paper template, which is taped to the concrete floor.  It isn't finished. 
The aft ends require trimming.  I marked out the area that gets removed with the Sharpie, then drilled a 1/8" hole as shown.  Next I used the dremel tool to cut along the green lines. 
Once the longeron was bent to the proper shape, I match-drilled it using the F-721B aft deck, whatever that is.
The aft deck clecoed to the longeron.  I still have to make a bend to the forward part of the longeron, then twist it.  But I've had enough of longerons for this day.
 
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