I started the wing tip project by first pre-forming the 3/4 x 1/8 x 48 spruce
by soaking for 24 hours then tying the bows to a 15 inch spare tire until they dried. I used 3 members to
form my bows as I wanted a thicker structure for rounding. I think it looks better rounded.
If you enlarge this photo you can get a better view of the front member that runs
along each nose rib and the full length of the wing panel. I used this as my starting point for the first bow.
I shortened this member to 1/2 inch, then thinned it from the back to 1/4 inch.
I used 3 bows to make the wing tip. I notched, after prefitting, all
3 bows to slide over the trailing edge. I then notched 2 bows to slide over the front member. The
first bow I did not notch.
Before any glue is mixed, test fit your bow. You will need to angle
cut the end of the spars to accommodate the curve of the bow. The first bow, without the notch, is placed
directly behind the nose rib member and using a "C" clamp, clamped in place. When I was satisfied
with the fit I used 3/4" aircraft nails to hold the bow to the end of both spars. I then made support
blocks out of scrap 3/4" wood to fit on the inside of the bow and up against the spars. I also made a block
for the trailing edge area. To speed things up, I used 5 minute epoxy to glue this first bow in place.
Once the glue has set on the first bow, and you have test fit the remaining 2 bows,
you can go ahead and glue the remaining bows in place. Slide the notched bows over the nose rib member and in
front of the first bow, and then use the "C" clamp and clamp everything in place. Use as many clamps
as necessary to ensure the bows have no gaps.
The next 2 photos show the trailing edge area and the front nose rib area.
You can see how the notched bows fit over and around the trailing edge and around the nose rib area. Sorry
the pics are poor.
These 2 photos show an almost completed wing tip bow. I used a belt
sander to grind and taper the bow to the trailing edge as well as the initial rounding of the entire structure.
I still have the front support member to glue in and do some finish sanding. I'm also thinking whether or
not I need to place a gusset over the trailing edge area.
Dear fellow novice aircraft builders out there. I thought I would share
a little "drama" with you. Please take note, after you have made your first gorgeous "Wing
Tip Bow", please get some cardboard or something to draw on and make a template of the dimensions or curvature of
your bow! As I do try to appear competent, I do mess up from time to time. What I am trying to
say is that the wing tip bow on this web site is the third one I have made, and out of all 3, there is not one that looks
the same! I can fix this of course, but its more time wasted. Make and use a master template
for all subsequent bows. (I'm still smiling)
