I'm really really behind on posting anything about this project, or anything for that matter. So many things have happened, including finishing the new spindle install, bracing the frame to add stiffness, real milling vices, and much much more. I hope to get back to updating the things on this project.
The video above shows it cutting aluminum with a 1/4" end mill at about 11 ipm. The depth was somewhere around 1/16" at the time. It doesn't seem to have any trouble with this at all, and in fact for the video we were having some problems with the lower axis. Some time in the past, without anyone realizing it, we must have driven it off the lead screw part way and lost most of the bearings out of the ballnut. There were maybe 10 in there where there should have been 80ish. I suspect we can go faster and cleaner once we get that sorted out.