Sounds like a good plan. I would buy the spindle assembly/housing, Ebay has a few of them last time I looked. Maybe buying that CNC lathe that you referenced above would be a good starting point, at least it would have a lot of the hardware that you will need. For $4K it might be worth a look, or you might look around for a less expensive one. If I wanted to build a lathe, that's what I would do.
''Mission creep'' will get you every time
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