Good small lathe for CNC conversion

[cameraman32]

I'm hoping to make a small CNC lathe, retrofit something small and cheap with ballscrews and steppers, and am wondering if anyone has some recommendations?

Right now i'm looking at the Shop Fox M1016 I found on ebay for $1,200, it looks like a good candidate. or the Birmingham , YCL 920 BD Lathe http://www.billstoolcrib.com/Lathbir920.htm

I've been doing a bit of cnc mill work, but never lathe. Is there some sort of manual tool changing system for a lathe's toolpost that can be accurately repeatable to change tools out without having to re-zero every time?

Any suggestions would be welcome, Thanks!

[Al_The_Man]

I am converting a Lathemaster 9 x30 for someone, these are built well for an ROC lathe, Flame hardened ways etc.
A lot of the mechanics come off when CNC'ing, so that is something to keep in mind, there was someone on ebay selling a lot of HiWin precision ballscrews that are ideal.
Another thing to consider if converting to variable speed spindle motor, is do you need a gearbox?
There are also some previous posts here on conversion of the Lathemaster.
Al.

[cameraman32]

That lathe does look like a good candidate. Thanks!

How do you accurately change out cutting bits on your machines so they are exactly the same every time?

[cameraman32]

For the gearbox/belt system that turns the spindle I'd keep that, and put an encoder on it so Mach3 could read the speed and still be able to turn threads without needing precise control of the speed. All the gears for the bed could be tossed since the motorized leadscrew would replace it. That is my thought anyway. What has been your experience?

[Al_The_Man]

Gearing for the lead screw can go. We removed the tool post and compound slide, and replaced them with a larger quick change tool post BXA size, which is really for a 10"-15" lathe, but there was room with for the BXA with the slide gone, and it adds rigidity.
There are some home built Rotary tool posts around, but there is not much room on a smaller lathe.
If you use the QCTP, the repeatability is there, and if the tools are numbered, you can call up a tool number for the offset.
Al.