NEW UPDATE: 1/5/2016
I've updated the Tool Holder, so if you print it off, the cutting edge of your tool should actually be lined up with the center of the part you're turning.
This isn't entirely true though, it's intentionally a little low, so you'll probably have to shim it up just a tad. It's just easier to shim the tool up versus the post being too high and being unable to shim it down in this current design.
I haven't the time to test it all myself, but unless my math is wrong this whole thing should be good to go.
Let me know if it works for you!
P.s. I also made the angle increments a little larger to the print a bit clearer.
Beta 1.1 of my Micro Lathe Frame.
I can now recommend printing everything except the Tool Holder, top and bottom. These will be updated shortly.
In order to give chuck jaws reasonable clearance, the default Headstock height has been changed to 175mm. The Tailstock centering has been changed accordingly.
Cross Slide parts have been adjusted, such that the cap nuts used to secure them together no longer lie under the cross slide rods. Originally, it was impossible to secure them once assembled. Hilarious after such a long print, but all in good fun.
Tolerances have been adjusted for ease of use. You can just print and go with most of them.
If you don't want to risk a long print having bad tolerances in the primary guide rod holes, find a handful of bushings sized for 1/2 inch rod (or 3/8 inch for the cross slide) and size the appropriate rod holes in the SCAD files to those. With appropriate print settings (found down yonder), you can pound them in and not worry about it. The SCAD files should be commented well enough to find the right numbers to tweak. I'll be updating them as the design evolves.
I personally used bobwomble's three jaw chuck. It takes a bit of sanding, but it works, unless you want to buy a real chuck, which also works.
BOM and Parts list coming soon (tm).
Head Stock parts are printed as they stand.
Parts with Major through holes, (Cross Slide, Cross Slide Wings, Tailstock, Tool Holder) are printed holes facing up so they come out perfect.
You should print the tool holder (once I update it) with the opening facing upward, so about half a body lengths worth of supports are under it. This is an opening for a bolt, and as such, it needs to be very precise.
Print with atleast 2mm of shell to minimize shakes, wobbles, and quakes.
Ream holes a tad, and you should be dandy.