Finish tack-welding all of rear-end components

I took a bit of a hiatus from the bike project to do something else but I finally got back to it. It took a little while to get my head around it again, but I quickly got going.

I put the seat bottom on the rear frame parts and added the diagonal cross-member (which didn't work out very close to specification, but no matter — I made it symmetrical.)

The right side of the rear frame.

Some of the cut pieces fit perfectly together ...

Pieces of threaded pipe will let me take the frame apart.