Cutting out the parts from the
urethane and pvc foam: no pictures. |
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All the parts have been
cut out, now I am mounting the soft urethane top to the rear foam. This
is an easy assembly to keep square; assuming that your jig and table
are square that is.
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Just another picture from
the other side. |
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Just a picture to show the
thinned section at the end. In my opinion, the manual doesn't make it
sufficiently explicit which part of the urethane (top or
bottom) receives which reduced section. It can be figiured out from the
manual but it could be a lot more explicit. The top part of the wing
spar receives the "thicker" thinned down end section. |
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Putting on the bottom
urethane foam for the wing spar. It is very important to get this
absolutely square (vertical). This point is not at all emphasized in
the manual. With these sticks on the jig, it is not at all evident that
you will get consistent results. I took the time to verify that each
one was square and then epoxied it in place in addition to the usual
screws. |
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Just another picture of the bottom urethane being
installed. |
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The famous inside layups. What a pain in the #?!
Getting the fiberglass to lay down properly whilst respecting the fiber
angles was a real bear. I had thought about doing it in two layups as
other builders have done but in the end I did it in a single layup. The
only thing that didn't get put in a single layup was the square braces
which came a day later. In the end, I used a nice little jig made by
Jean-Pierre to put the fiberglass into the spar channel without
upsetting the fibers. I basically wet the fiberglass out with epoxy on
some plastic sheeting. I then transferred it to a piece of packing tape
coated foam roughly the size of the interior of the spar box, being
careful to fold the sides over onto the top of the carrying foam. I
then carried it all over and gently placed it in the spar box and
gently pulled up the fiberglass which was then placed on the sides. I
used small nails to hold the fiberglass on the vertical faces. A very
long layup. It took me 7 hours. You can see the CS4 sections for the
front of the wing spar behind the jig, ready to be put in place. |
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Here are the results after
curing for a day. No real problems, no delaminations were found after a
very thorough check. |
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You can see in this
picture that I have also applied the fiberglass to CS4 by the dark
diagonal green strip after the "break". |
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Another picture of one of
the braces. In a real dufus maneuver, I forgot to put the 3rd brace in
the center before applying the leading edge face of the wing spar box.
I will put this in later after I make the giant cutouts for the center
front of the wing spar box. |
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Here I am putting on the forward face of the wing spar box. I
have used all of my clamps and all of the weight that I could find. I
used some flat sheets of wood to avoid bending the forward face down.
It was still a bear to make sure that the edges of the wing spar box
top and bottom met the forward face of the wing spar box. When I
started removing material for the spar cap, I found that there were
some regions which had not been in good contact. |
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A view of the other side. |
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All the clamps have been removed. |
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The spar cap cutouts have been made top and bottom. These are
absolutely critical and I am going to verify one final time before
putting in the shear webs that they are the correct height. It seems
that the problem is usually to high and not to low. |
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I have also been sure to put on 45° marks for the shear web. I have also applied the protective newspaper and tape. |
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It is impossible to resist the temptation to see if the spar fits in the fuselage. Very encouraging, it fits!!! |