13 April 2013

Wings: Main spar. J-stiffener.

Today was the first day of building.  The plans call for cutting up some J-stiffener and aligning them to the spar flanges to match drill them.  The Dremel worked great for cutting and the Scotch-Brite smoothed the edges.

First, clamp on the J-stiffener, making sure they rise 1/16" above the flange edge.


Match drill and cleco as you go, checking that the 1/16" is consistent.  On the bottom flange, there are holes you're not supposed to match drill.  I marked those off with a marker and kept the clamps there to avoid a mistake.

 


But, in true form, why not make a mistake on your first build day?  Below is the tip of the left spar.  You can see the J-stiffener placed up against the upper flange with a bit of a shadow underneath it to indicate that the J-stiffener is placed above the spar body so that it rises 1/16" above the flange.  Now, the text specifically says that the J-stiffener should be flush with the edge of the flange.  I decided that meant it should be flush with the edge of that piece with a rectangular hole near the bottom flange.  After all, that's what the picture looks like.  Well, turns out the perspective of the drawing is cause for confusion.  Too bad I didn't realize it until after I cut up the J-stiffener and completed match drilling the entire left spar's J-stiffener.  I now need to get some more J-stiffener from Van's.


So, basically, I did what was on the left, rather than the right.

 

1 comment:

  1. I can totally see myself doing the same thing! The drawing is very misleading

    ReplyDelete