Good to see you back, and do a thread on your mill, I'm sure there will be people who build it, as I did this spring, finally. I would highly suggest this build to anyone, and it is very adaptable. I mostly followed the design, with a few changes.
I mostly wanted a small log mill for putting flats on poles for pole frame construction, and have been using up to 24 foot logs, so I made my rail system 27' long, requiring a "truss" of 1-1/2 box tube under the 2 x 4 top rails. I also went to 19" steel pulleys from surplus center, bored the centers for press fit bearings. I used a yanmar 10 hp diesel I had, and tho the power is probably about the same as a 13 hp gasser, I've been really impressed at how much milling I can do compared to a chainsaw mill, I can cut more on a gallon of diesel than I could with 5 gallons of mix using a CSM.
I've done quite a few fabrication jobs on various projects, so I didnt have any trouble looking at pics of mills, especially yours, and just going ahead with it. Maybe you could do a little write up on how you piece your mill together, some people might not know to build the rails first, then tack up the carridge, and make sure it's running straight before welding, and maybe some details I had to figure out, like setting the guide bearings so they are a bit below the bottoms of the wheels, I went with 3/4" maybe 1/2" would have been sufficient?
Anyway, as with any welding project of this nature, I would suggest to anyone building this to do a lot of tacking and fitting, and checking that things move smoothly as they move forward in the build, you dont have to over weld either, distortion is any welders biggest enemy.
That said, I think this is well within a beginner welders capability, a person could buy a buzzbox, some rod, and all the steel, and still be thousands ahead of buying a similar mill, with a better product in the end.
Thanks again for going to the effort to get this great design out to people, Russell