Looks great, you are getting your moneys worth of experience out of this kit!
Hah, that's the truth! This whole project was an education so far! The steam engine was probably my biggest "level up" so far, and this is challenging me further!
Today I finished 2 parts, the main sheet metal bodies of the boiler frame. The inner just requires cutting out a spot for the fire to get in
The outer requires just making some mounting holes, which I didn't snap pictures of.
Next, I needed to work on the chimney casting. There are two parts to machine on this casting. First I did the bore for the chimney itself. I tried doing this on the mill, and using the boring head, but I couldn't get it to stay still during the cut. SOO I did a better thing and made a holding ring for the lathe out of some aluminum:
After using a big drill bit, a boring bar, and a band saw, the jig was ready.
Then I clamped the casting inside of this in the 6 jaw, and bored until the copper chimney tube fit:
Next I had to machine the "bottom" of the casting to fit the OD of the tank. I've seen a few others do this with much more care and grace, but I tried the easy way. I used the now close fit chimney to line it up against my vise, and ballparked the boring head with a ruler. I then cut, tried it against the tank, then made it bigger over and over until it fit right.
I had ONE oopsie (see the spot the boring head nicked on top of the casting in the first pic), but I suspect some time with a Dremel and files will clean that up:
I'm the end after about a dozen adjustments, perfect fit!
I still have to drill mounting holes, but I ran out of time today.