A lathe is shown on a tabletop. Instead of a normal lathe workspace, there is an XY positioning platform in front of the chuck, with two toolposts mounted on the platform. Stepper motors are mounted on the platform to drive it. The lathe has no tailpiece.

Turning A Milling Machine Into A Lathe

If you’re planning to make a metalworking lathe out of a CNC milling machine, you probably don’t expect getting a position sensor to work to be your biggest challenge. Nevertheless, this was [Anthony Zhang]’s experience. Admittedly, the milling machine’s manufacturer sells a conversion kit, which greatly simplifies the more obviously difficult steps, but getting it to cut threads automatically took a few hacks.

The conversion started with a secondhand Taig MicroMill 2019DSL CNC mill, which was well-priced enough to be purchased specifically for conversion into a lathe. Taig’s conversion kit includes the spindle, tool posts, mounting hardware, and other necessary parts, and the modifications were simple enough to take only a few hours of disassembly and reassembly. The final lathe reuses the motors and control electronics from the CNC, and the milling motor drives the spindle through a set of pulleys. The Y-axis assembly isn’t used, but the X- and Z-axes hold the tool post in front of the spindle.

The biggest difficulty was in getting the spindle indexing sensor working, which was essential for cutting accurate threads. [Anthony] started with Taig’s sensor, but there was no guarantee that it would work with the mill’s motor controller, since it was designed for a lathe controller. Rather than plug it in and hope it worked, he ended up disassembling both the sensor and the controller to reverse-engineer the wiring.

He found that it was an inductive sensor which detected a steel insert in the spindle’s pulley, and that a slight modification to the controller would let the two work together. In the end, however, he decided against using it, since it would have taken up the controller’s entire I/O port. Instead, [Anthony] wired his own I/O connector, which interfaces with a commercial inductive sensor and the end-limit switches. A side benefit was that the new indexing sensor’s mounting didn’t block moving the pulley’s drive belt, as the original had.

The end result was a small, versatile CNC lathe with enough accuracy to cut useful threads with some care. If you aren’t lucky enough to get a Taig to convert, there are quite a few people who’ve built their own CNC lathes, ranging from relatively simple to the extremely advanced.

Modulathe Is CNC Ready And Will Machine What You Want

Once upon a time, lathes were big heavy machines driven by massive AC motors, hewn out of cast iron and sheer will. Today, we have machine tools of all shapes and sizes, many of which are compact and tidy DIY creations. [Maxim Kachurovskiy]’s Modulathe fits the latter description nicely.

The concept behind the project was simple—this was to be a modular, digital lathe that was open-source and readily buildable on a DIY level, without sacrificing usability. To that end, Modulathe is kitted out to process metal, wooden, and plastic parts, so you can fabricate in whatever material is most appropriate for your needs.

It features a 125 mm chuck and an MT5 spindle, and relies on 15 mm linear rails, 12 mm ball screws, and NEMA23 stepper motors. Because its modular, much of the rest of the design is up to you. You can set it up with pretty much any practical bed length—just choose the right ball screw and rail to achieve it. It’s also set up to work however you like—you can manually operate it, or use it for CNC machining tasks instead.

If you want a small lathe that’s customizable and CNC-ready, this might be the project you’re looking for. We’ve featured some other similar projects in this space, too. Do your research, and explore! If you come up with new grand machine tools of your own design, don’t hesitate to let us know!

Thanks to [mip] for the tip!