Benchtop Lathe Gets An Electronic Leadscrew Makeover

The king of machine tools is the lathe, and if the king has a heart, it’s probably the leadscrew. That’s the bit that allows threading operations, arguably the most important job a lathe can tackle. It’s a simple concept, really – the leadscrew is mechanically linked through gears to the spindle so that the cutting tool moves along the long axis of the workpiece as it rotates, allowing it to cut threads of the desired pitch.

But what’s simple in concept can be complicated in reality. As [Clough42] points out, most lathes couple the lead screw to the spindle drive through a complex series of gears that need to be swapped in and out to accommodate different thread pitches, and makes going from imperial to metric a whole ball of wax by itself. So he set about building an electronic leadscrew for his lathe. The idea is to forgo the gear train and drive the leadscrew directly with a high-quality stepper motor. That sounds easy enough, but bear in mind that the translation of the tool needs to be perfectly synchronized with the rotation of the spindle to make threading possible. That will be accomplished with an industrial-grade quadrature encoder coupled to the spindle, which will tell software running on a TI LaunchPad how fast to turn the stepper – and in which direction, to control thread handedness. The video below has some great detail on real-time operating systems on microcontrollers as well as tests on all the hardware to be used.

This is only a proof of concept at this point, but we’re looking forward to the rest of this series. In the meantime, [Quinn Dunki]’s excellent series on choosing a lathe should keep you going.

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TI’s inexpensive Piccolo and Stellaris dev boards

Texas Instruments is trying to take the success it had with the LaunchPad and apply it to other chip architectures. The board seen above is their new C2000 Piccolo LaunchPad. It’s a development board for the F28027 chip. This 32-bit offering is a part we know nothing about. A first look shows a clock speed between 40 and 60 MHz, 64k of Flash memory, and a JTAG programming interface. It sounds like an unrestricted copy of Code Composer Studio is also available to use as the development environment. At $17 won’t break the bank, but we also don’t feel that welling of excitement to get in on one of these units.

What does get us excited is the Stellaris LaunchPad offering. It’s not available yet (which always makes us want it more), but you can enter a drawing to get a free one when they are released. Be warned, with only 25 up for grabs the odds are against you. There are no details, other than a target price of $4.99 for the ARM development board. We’ve had a lot of fun with the STM32 ARM board, and this might be a new adventure to undertake.

[Thanks Máté]