This was designed to produce a tool that is similar in function to a fully fledge mini lathe that one can buy while being at a cheaper price. It was created using OpenSCAD for the CAD software.

I used 5/16" smooth rods and 5/16-18 threaded rods to created the structure. The threaded rods go through bearings and have nuts on both sides of the bearings to keep them in place. The bottom threaded rods are used to maintain a square tool. The smooth rods are fitted into the holes in the 3D printed parts and pinched in place by the threaded rods being tightened down. There is a 90V DC motor that is hooked up to an AC DC motor controller allowing for speed control up to 1800 RPM. This motor has a keyed saft that a 3D printed Chuck hooks up to. At the current time, i have had Printer issues and have not been able to get the Chuck to print. The motor sits ontop of a motor mount that is tied to the threaded rods. This makes for one complete unit. The carriage is designed to have smooth rods pass through the 5/16 holes, and have bearings with threaded rod attached through the center. This then lets the tool holder move across the carriage. The tool holder was designed to allow for the tool bit to either be used to turn the face or to turn the side of the part with its open ended side. It has slots in the top for 5/16-18 nuts and holes for the bolts to go through and pinch the tool to the bottom. If needed, one can shim the tool up if there is enough space. 

For hardware, i used 5/16" smooth rods, 5/16-18 threaded rods, 5/16-18 bolts and nuts, 3/8 rotational bearings ( as this was the only size available at the time), these were the hardware parts that i needed to buy from the store for my part of the design.

For the chuck, i found the design here:https://www.thingiverse.com/thing:624625 and changed a few parameters to make it fit my application. For this, i followed the creaters instructions on hardware and purchased: 8x M3*50 x10, 8x M4-.7 x20, and 4x M4-.70 x40 screws. 

For the linear bearings, i was unable to find bearings to purchase, so i found 3D printable ones here:https://www.thingiverse.com/thing:1430232 I used the bearing without the mounting bracket, and found these to be the correct size already for my rods.

Motor link:https://www.amazon.com/gp/product/B06XGFKGC1/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Controller Link: https://www.amazon.com/gp/product/B076KPP92X/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1

I had to modify my terminals to fit my controller, and i had to wire terminals to the motor and then attach a power cord to the controller. 

For attaching the linear bearings and thhe nuts to the carriage and tool holder, i used JB weld apoxy.

Please feel free to make changes to the design as you see fit or to accomodate your applications. 

Here is a link to an industry made mini lathe that this was set to compete with. For only having 2 weeks i think the design is relatively comprable. 

Link:https://www.thingiverse.com/thing:1430232 This is the cheapest one i could find on the market at this size. $600

In comparison, mine totals to : 191.13 before tax on the hardware. The BOM is included.