diy-cnc-machine

A step-by-step guide to build a large 3D-printed CNC router from scratch. The repository is documentation and CAD files, not code: a complete bill of materials, STL/OBJ files for every 3D-printed part, the master Fusion 360 CAD design, and instructions covering both the physical assembly and the open-source control software. It's Max Fischer's writeup of Ivan Miranda's design, meant as a companion to Ivan's YouTube build videos. The machine is large — an aluminium-extrusion frame roughly 900 mm on a side with three moving axes and a handheld router as the spindle.

How it's organized

The README is one long assembly manual with an anchored table of contents. The physical build runs through nine stages in the order you'd actually assemble them: main frame (two interlocked aluminium frames on threaded rods), Y-axis (side plates, geared stepper motors, idlers, HTD5M belts, tensioners, end-stop mounts), X-axis and Z-axis (bridge beams, carriage, a vertical slider driven by an acme rod and nut, cable chains), stepper motors and end-stops (wire extension and routing), the router mount, two electronic boxes, the full electrical wiring, the wasteboard, and a dust shoe. Then a software section covers flashing grbl onto an Arduino Uno through the Arduino IDE, connecting a G-code sender (UGS), and tuning the GRBL configuration.

Parts are tracked with a unique item number per part — O07 for the 900 mm profiles, P25 for a printed alignment jig, S03 for a screw size, and so on — so the prose can point at exact items. The full list lives in a separate BILLOFMATERIAL.md with images and download links, backed by a Bill_of_material.xlsx spreadsheet with per-part comments (also mirrored on Google Drive).

Two model formats serve two jobs. STL and OBJ files are the printable parts you feed to a slicer. The master CAD is a single Fusion 360 archive (fusion_360_cad_files.f3z) holding all the measurements and the complete assembly — you import it into Fusion 360 (free for personal use) to check distances or modify a part before printing. The README warns the master file is messy, which is why the parts were pulled out into a separate BOM.

Who it's for

Makers who already have a 3D printer and are comfortable with hand tools. The build assumes a bench drill, drill taps (M3 through M5), a soldering iron for extending motor wires, and patience for drilling and tapping dozens of holes in aluminium extrusion. You source the aluminium profiles, MGN12H linear rails, belts, acme rod, geared NEMA17 steppers, an Arduino Uno with a CNC shield and stepper drivers, a power supply, and a router yourself. This is not a kit and not a click-to-order machine.

Limitations

It's a single specific machine, not a parametric platform — the guide documents one design at one size. The control electronics are a hobby-grade Arduino Uno plus CNC shield running grbl v1.1 (the guide notes a config.h tweak needed because grbl changed the Z end-stop pin), not an industrial controller. The design credit and the "real" blueprints belong to Ivan Miranda; the repo hosts his STL files to make the build easier, but the author asks you to buy Ivan's $25 blueprint pack to support him and get Discord access. GitHub reports the license as NOASSERTION — it's a custom permissive grant from Ivan Miranda, not an OSI license: you may print, sell parts, sell machines, sell build courses, and modify and repost the files, as long as you don't sell the files themselves and you keep the license and credit intact. A few small parts (the Z-axis end-stop trigger, ordinary end-stops, rail supports) come from a community repo, 4cello/mirandacnc-community.

This is a hardware/CAD project rather than the usual software entry — filed here as a reference build, not a tool to run. For a different flavor of open-hardware CAD release, compare valve-steam-controller-cad: Valve published only the outer shell under a non-commercial Creative Commons license, whereas this build ships the complete machine and explicitly permits commercial use of everything except reselling the files.

Repo: maxvfischer/DIY-CNC-machine — 1,928 stars, custom Ivan Miranda license (GitHub: NOASSERTION).