Date: November 29, 2007

I got a chance to work on the wingtip tonight. Finally. I've been trying to get some patio work done before it gets too cold. But tonight I wanted to work on my plane.

I started with cutting the bottom spars even with the outside edge of the wing rib. A little sanding to make the cut flush. (Picture 1)

Next, to work cutting the wingtip piece. First I extended the base line of the wingtip. (Picture 2)

Third, I finally cut the extra material off the back of the wing. I measured 9 - 1/8" from the back of the wing spar, then I used a piece of angle aluminum to form a straight edge. (Picture 3) Once the straight edge was securely clamped down. I cut through the balsa with a sharp blade. (Picture 4)

With the chord of the wing figured out, I could then mark the end point of the modified wingtip template. (Picture 5)

Once I had the template length marked, I used scotch 77 to glue three pieces of 3/16" balsa together. I glued the paper template on top of the stack. I fired up the bandsaw and made the cut. I used one of the cut pieces to mark the top wing spars for cutting. I put notches in the wingtip for the spars to fit in. Then put it in place. I marked the spars for cutting. (Picture 6, 7 and 8)

With the spars cut, I filed and sanded them down until I got a good fit with the actual wing tip. I used a file to put a bevel on the bottom edge of the wingtip. I want it to fit flush with the bottom of the wing rib. I used masking tape to hold the wingtip in place while I made sure it was shaped properly. (picture 9)

To make sure the wingtip is shaped properly, I put a ruler along the top of the ribs, and extended it out to the wingtip. Where the ruler touched the wingtip, I put a mark. (Picture 10 and 11)

I rejoined the two wingtip pieces, hand drew lines between the dots, and used the bandsaw to cut the excess away. Once that was done, I dry fitted the wingtip, and checked with a ruler again. (Picture 12, 13 and 14)

Finally, I could break out the glue bottle. I glued the wingtip in place, and held it there with masking tape. (Picture 15 and 16)

Enough for one evening. The other wingtip should go more quickly, now that I have all the templates made.

Picture 1: The bottom spars cut and sanded flush with the wing rib.
Picture 2: Extending the bottom line of the wingtip piece.
Picture 3: With the trailing edge of the wing measured, angle aluminum clamped in place.
Picture 4: Using straight edge to cut against.
Picture 5: Marking the modified wingtip template for the endpoint.
Picture 6: Using notched wingtip piece to mark top wing spars for cutting.
Picture 7: Marking the wing spars for cutting.
Picture 8: Marking the wing spars for cutting.