I set the 3 degree change and it
lined right up with the 7 1/2"
point on the outside of the box
from the top. (as shown in the
plans)
All lines are drawn.

I used a fine line black marker
on the lines that will be used.
Using a scanner, I duplicated
the 0.125 4130 sheet parts.

I printed them out and cut on the
line.

Here they are sitting on the main
template.
I cut the 3/4" inch square
tubing to a rough
measurement of 26".  I
notched the square at the
center and bent them up 3
degrees.  After welding, I
sanded them flat.

The cardboard template
will be used to cut out the
0.063 sheet when I order
more.

Also shown are some
finished 5/16" ID
bushings for the spar box.
More 0.063 sheet arrived
and I cut the front plate.

The bent square is ready
to weld on the top and
bottom.

Clamped to prevent
warpage.
MIG welded top.

I used mig welding to
reduce warpage of the thin
sheet.  

Make sure your weld has
good penetration.
Time to start on the spar box.

It is shown on page S-17 of the
stretch plans.

I began by drawing a 8 1/8" x 23
5/8" box on light cardboard.

I then started adding
measurements and lines from
the plans.