Hello Gents,
I have a need for CNC control for lathe parts ~ 2" long x 1.75" D. I currently have a southbend heavy 10 and old pulley head bridgeport along with a multitude of tig/mig welders. I can do 90% of what I want to do on the manual but I turn a lot of titanium/17-4 and form tools don't work so hot on either.

So on to the questions
I could do MOST everything I wanted to do by CNC the compound and the cross slide. Obviously no threads with just that but I can thread manually. Is this viable for the occasional use

If I were to build a SMALL CNC instead, I would want to use collets primarily, preferably something with a big enough spindle bore to pass 1.75". I could use 5C Emergencies and cut everything to size first but then would have 2 operations with a part flip instead. I started looking at builds and linear bearings and came across what is essentially pre-built tables with 2 linear rails and a ball screw built in on eBay/my local automation guy. Are these things viable? Can you just mount one on top of the other and go to town? Here is a cheap example of what I'm referring to. I don't think you can buy the piece parts for that?

https://www.ebay.com/itm/200MM-Strok....c100667.m2042

Thanks in advance for the help!

ETA, tolerance required is probably around +/- 0.003. Not super precise like some. Its more I make a lot of similar shapes that have curves making it difficult to turn on a manual (a ball turner wouldn't help)