We’re no strangers to [Ivan]’s work and this time he’s building a relatively small CNC machine using extrusion, 3D printed parts, and a Makita router. The plans are available at a small cost, but just watching the accelerated build is fascinating.
You might think you could just attach something to an existing 3D printer frame that cuts like a Dremel tool. You can do that, but for most purposes, you need something stiffer than most desktop printers. You can see how solid this build is with multiple extrusions forming the base and very rigid axes.
Judging from the video, the machine made short work of some aluminum plate. Of course, some of that is in the choice of tool, but it appears the machine is stable enough to hold the workpiece and the tool stable to allow this sort of service. [Ivan] says the machine cost him about 600 Euro ($670 USD) and you need a printer that can create parts as large as 180 x 180 mm.
There are quite a few similar mostly 3D printed machines on Thingiverse, including some that have been through multiple versions. If you have an old 3D printer sitting around for parts, you may have nearly everything you need if you add some printed parts, presumably from your new printer.