Serious structural work today. The struts hold the wings in position so it's important to get this bit correct. Although the plans are fairly clear I wasn't sure exactly how to go about making the ends on the strut and stub strut but thanks to Jim Stanton and his article in a back issue of the Tailwind times (TT10) the approach became clear. The struts are made from streamline 4130 steel tubing 2.5" wide, 1.0" deep and with a wall thickness of 0.049". The cross section of the tube is like an elongated egg shape to minimise drag.An 11' length of tubing is sufficient to make the
two struts and two stub struts (these are welded to the fuselage). The 11' length was cut in half and then the first job was to flatten the end of the tubing that will be used for the stub strut. The line on the tubing marks the start of the taper down to the end. Once the end was down to rough size (0.095" gap), the sides of the tube were cut off to make a wedge shape. Next job was to cut a piece of 0.095" thick steel plate 1-1/4" long and matching the wedge shape to fit into the 
end of the tubing. With the end clamped in the vice this was then welded into position as in the second picture. Next, strengthening plates made from 0.065" thick plate were cut out and clamped to the sides of the joint (3rd picture). These were then welded into position. This creates a flat area roughly 1-1/4" square with an even thickness of about 0.325"and a 3/8" hole was then drilled centrally in this flat to take the mounting bolt. A second end was made in the same way on the other length of tubing. The two stub struts were then cut from the lengths of 
streamline tubing ready for welding to the fuselage.The lower end of the first strut was then prepared. First, a piece of 0.065" thick steel sheet was folded into a "U" shape to fit over the end of the stub strut. The end of the sreamline tubing was flattened to create a rectangular end the same size as the outside dimension of the "U" which was welded into place as shown in the 5th picture. Finally strengthening plates were welded to the outside of the tubing and the fork drilled to take a 3/8" diameter bolt. As before, the process was then repeated for the second strut. Next job is to weld the stub struts to the fuselage.
