After a bunch of planning and many hours in front of the computer figuring out the specs for the frame, and making some necessary bits for the jig, it's finally time to start cutting, filing and joining metal.
Day one consisted of making all the necessary adjustments to the jig, prepping tubes by marking out butting and where to cut etc.
When I was just about to start mitering the seat tube I discovered my first mistake - I had forgotten to take into account that the seat tube was externally butted at the bottom, and thus had a bigger diameter. Meaning that my mitering templates that I had painstakingly prepared needed to be adjusted and re-printed. Oh well, that was a minor thing to get wrong. Back to the computer to make the necessary changes and update the cutting templates.
With new templates for the seattube and the downtube I got started with the cutting. Always measuring multiple times before cutting or making any irreversible changes to the tubes. The seattube got mitered up to the bottom bracket first. Then downtube to BB.
The most challenging part was to miter the downtube to the tapered headtube. I am happy with the resulting miter and I think I got it really tight. Not much room for error since the other end of the downtube was already mitered to the BB.
At the end of day one I had mitered up all the tubes for the front triangle. Slow progress, but I rather get things right than work too fast.