Minamil: A Three-Axis CNC Mill That Works for $45

Built mostly from laser-cut hardboard and a screwdriver, Minamil is a three-axis CNC device that can mill fine-pitch PCBs and comes to about $15 per axis. The design is intended as a DIY project made from ready-to-assemble components and simple tools. The structural parts are laser-cut from hardboard, but no further fabrication is needed for the working parts.

In part, this project is a response to the lack of hands-on practical education, a limitation created by the pandemic. So, here is a cheap, minimal way to practice CNC programming and machining. While personal 3D printing has become more and more common, subtractive processes like CNC milling remain less accessible outside commercial spaces due in part to cost, mess, and complexity. Minamil seeks to solve many of these issues, described by creator Paul McClay as an "unprecedented combination” of assembly with ready parts, low cost, precision, and the ability to store it rather than requiring a fixed installation.

As far as the “ready parts,” the Minamil is based on two main assemblies: the X and Y axes and the Z-axis and tool clamp. These are built from a few specific hardware components, as well as some laser-cut flat pieces for which detailed assembly instructions are provided. The design is currently up and running well enough to produce a video demo. The available documentation also includes design process and decisions, including issues encountered, performance testing, information about circuit board milling, and more.

As of right now, the project is ready for someone to build on their own by gathering specified parts and following detailed instructions. Kits are a possibility but not yet available as of this post. It’s meant to be a project anyone can jump in on, including the fact that it works well for what it does now and includes space for future development.