My Wooden Airplane
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1/14/2011 - 1/18/2011

New Fin Spar

Well, if you remember back in Feb, 2009, I ran into a discrepancy with the Fin and Rudder plans. Basically, the "scale" drawing ended up not being "scale" at all. Several dimensions were drawn one way, but specified as something else. (For example, on the plans the distance between rib F2 and F3 measures 385 mm, but is specified as being only 335 mm. That's a difference of 50 mm, or about 2 inches.) I made a decision to go with the way the plans were drawn, since if I tried to go with the way the dimensions were specified, some of the ribs ended up being the wrong length. Again, as mentioned at the time, this resulted in rib F2 being two inches too low, and wouldn't have left enough room for the Horizontal Stabilizer. I might have actually left it like this, and tried to find some other work-around, except that there was a revision in the plans. Instead of having both stabilizer bracing wires attach to the same place on the vertical fin, an additional bracket needed to be added near the leading edge of the fin so that the forward stabilizer bracing wire has it's own attach point. So, I decided to go ahead and rebuild the vertical fin, using the specified dimensions, rather than the drawn dimensions.

So, here is the new fin spar.

Total Time: 3.5 hrs.