DIY CNC Router

I designed and manufactured a 3-axis CNC router utilizing Fusion 360 for the CAD and CAM and machined components using my school's HAAS TM-2P CNC mill. Yes, I used a CNC to make a CNC!

The CNC Router has a cutting volume of 19" x 21" x 6" in the x, y, z axis respectively. This machine is designed to cut various materials such as aluminum, brass, mild steel, woods and plastics.

​Since I plan on keeping this in my apartment, I decided to utilize a moving gantry design to maximize tool travel while minimizing the space the machine takes up. I've designed the electronic components to consume less than 2 kW of power in order to use a standard 120V 20A circuit. This machine is also designed to be easily disassembled into subassemblies that can fit through a standard size doorway.

I'm currently a junior at Binghamton University studying Mechanical Engineering. I'm very passionate about DIY projects and mechanical design. This project has allowed me the precision and automation to explore more DIY projects.

The motors selected are Nema 23 stepper motors supplemented with DM556T motor drivers. I utilized an Arduino for the controller and GRBL firmware to convert G-Code into PWM signals. The electronics enclosure is a PC tower purchased on Facebook Marketplace.

The linear rails are HGR20 and HGH20 linear rails and guide blocks. The axis is driven by SFU1605 ballscrews powered by the NEMA 23 stepper motors. This actuator assembly gives the machine 0.025mm (0.001") of linear travel per full step of the stepper motor.

The frame of the machine was machined out of 3/8" thick 6" x 4" rectangular tubing grounded to a 3" x 3" x 0.25" steel plate. The other parts are made out of aluminum 2024 and 6061-T6 scrap purchased from various metal suppliers.

The first step of every project is to load into Fusion 360 and start CAD'ing. It was important to me to design everything in a full assembly including off-the-shelf components to be able to have a 100% completed design in CAD before I started machining.

FEA was conducted on the gantry assembly to ensure my design has less than 0.001" of deflection at the tool under peak loading conditions. Cutting force analysis was conducted to determine a peak cutting force of 200N at the flutes of the cutting tool. Given these conditions, a deflection of 0.0008" was seen in the FEA results passing my requirement. This ensured I was able to cut aluminum alloys at speeds that could keep up with other industrial grade CNCs.

I've designed all components to be machined in-house at my school's Fabrication Lab. Most components were water jet out of plate stock and then machined to final size. These parts were CNC milled on my school's Haas TM-2P. I've generated all the G-Code for these operations using Fusion 360 CAM and learned how to operate my school's Haas TM-2P for this project. 

When building CNC machines, the assembly process is very important. The linear rails need to be parallel and square to one another. In addition, the spindle needs to be trammed to ensure the tool is perpendicular to the machine base.

A surface plate and various dial indicator setups were utilized to ensure parallelism and perpendicularity were within the tolerance I specified in the drawings.

On the electrical side, lots of soldering and crimping was done to ensure robust wiring. I utilized multi-conductor cable with shielded grounds and snaked everything through drag-chains to keep things organized.

Since building the machine, I've utilized its rigidity to mill many different parts out of aluminum, wood, and brass. I've upgraded 3D printed parts on the machine by milling billet aluminum with the machine to replace these components. This machine has been able to mill features within 0.001" of the modeled dimensions.

I plan on using this machine to give me the opportunity to fabricate parts more precisely for future projects. In addition, I plan on creating a small woodworking/metalworking business and this machine will allow me to automate this process with accurate and consistent results.