 I started the spar by taping two sheets of 2" thick insulating foam together. (This was just for the center section of the wing) I then drew a reference line and then drew the spar. After all measurements were checked a hundred times, I glassed over the lines drawn on the foam. |
 The center section was then cut out of the foam sheets. |
 I then added the outside sections and glassed one side of the foam. I had to move it outside to get the whole thing in one picture. The spar is 29' wide. The wing span will be 32". The wing tips will be solid foam appliances. |
 This picture shows the jig built to level, plumb, and align the spar. |
 Protecting the spar while welding the jig in place. |
 The other end of the jig. |
 After jigging the spar, I drew a new reference line. This allowed me to check the accuracy of the spar. |
 Oops! After re-drawing the reference lines, I found I had made a mistake. (Not the first and I'm sure not the last.) The Corsair had an 8.5 degree dihedral on the outer wing pannels. Mine was 12 degrees. The good thing about composites is the ease of fixing a mistake. This picture shows how I cut the spar and let the wing sag 3.5 degrees. |
 I then filled the gap with a wedge of foam and glassed over it. |
 After resetting the dihedral, I had to redraw the reference lines. |
 This is a panoramic shot of the whole spar before applying the spar cap. Notice the markings for the ends of each layer of laminate. |
|
 The bottom line now must be cut to size the spar, in preparation for the bottom spar cap. |
 I had to modify a reciprocal saw blade to fit in a jig saw to cut through the 2" foam and fiber glass. I use that for the curves. The straight cuts are done with a circular saw. The fiber glass is hard to cut with either of these saws. I use the best saws I can so that I get a nice 90 degree angle and a nice surface for the cap. Some block sanding and filling is still required. |
 After the cut, a little extra support is needed where the glass had been cut to change the dihedral. Another angle check, and it's time to add the bottom spar cap. |
 I turned the spar over to lay up the bottom cap. This cap consists of fourteen layers of unidirectional fiber glass tape. The top cap is eleven layers. This is a test piece. It is not built to support a 3500lb aircraft at 8g. It is 2500lbs at 2g. It will be tested to destruction after the wing molds are built. It is just a test to insure my methods and math are correct. |
 Of course I had to re-check all of the angles again. |
 This is how the spar cap is trimmed. The spar web (face of the spar) does not show up well, but it is there. It is three layers of bi-directional, 7781 glass, laid at a 45 degree angle to the reference line. |
 Sanding insures a clean corner for the cap meeting the web. |
 A few layers of 7781 at a 45 degree angle is used to keep the bottom cap attached to the web. |
 The top cap is secured to the web. Now it's ready for the ribs. |
| Click on any photo to see an expanded version. | ||