Yesterday, I "flipped" the fuselage bottom so I could tack weld the underside of the tubes. It was a big moment because it would verify the fuselage bottom was symmetrical. I took all the conduit clamps off and then flipped it over, leaving the jig blocks in place. It fit! I was so excited that it actually worked! All that measuring really paid off. I realize that welding will introduce much more distortion, but at least it's nice to know I'll start off not fighting something that isn't lined up from the get go.
I also verified my tubes were in the right place because I marked each large cross tube with the proper station and orientation. Another bonus was seeing the fit of each cluster when I couldn't see at all, especially the "smooshed" side. Also, I was checking the fit of the fishmouths in the clusters and other places I couldn't see until now. They all looked like a really good fit, so that was a big plus as well.
After practicing my tack welding again, I went ahead and tacked together the remaining tubes. I then pulled it out of the jig and slid it under the jig table for safe keeping until I need it.
