Even though the Roland MDX-20 CNC mill fetched a pretty penny when it was first made available 12 years ago, there were a few features that made any builder lucky enough to own one scratch their head. The only way for a computer to communicate with this mill was through an RS-232 connection, and instead of a normal control protocol such as GCode, the Roland mill uses a very proprietary software package.

[Johan] fixed these problems and at the same time turned this wonderful machine into a tool for the 21st century. Now, instead of running a very long serial cable to his mill with a serial to USB converter at the end, he can just plug a USB cable into his mill with the addition of an FTDI USB to serial chip wired directly to the mill’s circuit board.

Stock, the Roland mill used a very strange proprietary communications protocol. [Johan] was able to reverse engineer this protocol by tracing out a few simple shapes and curves and taking a highlighter to the printout of the resulting file. Instead of the outdated software package that shipped with his mill, [Johan] can now export tool paths directly from his CAD program and send them over a USB cable.

It really is a shame such a nice machine like [Johan]’s mill suffered from the glaring shortsightedness of Roland executives 12 years ago, but at least now [Johan] has a machine that should easily last another decade.