The extra piece of stainless steel channel I needed arrived this morning so I fabricated the support for the front end of the bottom stringers. These sit off the bottom of the fuselage by 1-5/8" to provide clearance for the control column torque tube. The mounts at station 48 are also fabricated to make the bottom of the stringer 1-5/8" below the bottom of the main fuselage structure. The rearmost mounts sits flush to the rear cross member. Then the remaining mounts for the stringers were cut to follow the natural curve of the stringer and welded or brazed, as appropriate, to the fuselage cross members and diagonals. There are about 5 of the stand-offs still to final weld tomorrow then the mounts can be match-drilled to the underside of the stringers ready to be pop-riveted into place before covering. You can see in the bottom picture a hole drilled through each mount into the stand-off. This is needed to allow the air to escape when welding otherwise as the tube heats the air inside expands and pops through the weld pool making it impossible to get a clean joint.Based on the plans, I don't think it is strictly necessary to put mounts on the diagonals but putting them there will help to provide support for the stringers which in turn support the fabric and further increase the stiffness of the fuselage.
The extra piece of stainless steel channel I needed arrived this morning so I fabricated the support for the front end of the bottom stringers. These sit off the bottom of the fuselage by 1-5/8" to provide clearance for the control column torque tube. The mounts at station 48 are also fabricated to make the bottom of the stringer 1-5/8" below the bottom of the main fuselage structure. The rearmost mounts sits flush to the rear cross member. Then the remaining mounts for the stringers were cut to follow the natural curve of the stringer and welded or brazed, as appropriate, to the fuselage cross members and diagonals. There are about 5 of the stand-offs still to final weld tomorrow then the mounts can be match-drilled to the underside of the stringers ready to be pop-riveted into place before covering. You can see in the bottom picture a hole drilled through each mount into the stand-off. This is needed to allow the air to escape when welding otherwise as the tube heats the air inside expands and pops through the weld pool making it impossible to get a clean joint.Based on the plans, I don't think it is strictly necessary to put mounts on the diagonals but putting them there will help to provide support for the stringers which in turn support the fabric and further increase the stiffness of the fuselage.
