A year ago I designed and built my cnc mill which came out great. Using it for making large rc helicopter parts. I've been able to mill most of my round parts, but obviously it's not optimal and a lathe would make things so much easier and open up a lot of possibilities.
I'm pretty confident with the whole build other than spindle/headstock. Ill use hiwin linear bearings, ballscrews, and steppers. Probably combination of quick change and gang tooling, no plans for turret. Mostly small aluminum parts, max diameter around 2 inch, with the exception of some delrin gear blanks up to 5 inch. So doesn't need to be a big powerful lathe, but would like to hold very good tolerances.
The headstock and spindle is where I get lost. I don't have access to a lathe so buying this stuff premade would be optimal. What options should I consider? I've seen some guys mention using the guts of a 5c indexer as a spindle. I think I could possibly design and mill my own headstock out of multiple thick aluminum plates with the bearing pockets just interpolated on my mill. I also have a nice rotary axis that could be layed flat for milling nice round bearing pockets in the headstock plates. The spindle itself at the very least I will need premade. I Would like the option of using 5c collets as well as smaller 3 and 4 jaw setups.
So what should I consider for options? Find a spindle and build a headstock around it? Or just look for a complete used headstock/spindle assembly? Any recommendations would be great.