2/8/2026 - Design/documentation

I Finished The cad of the model went through 3 iterations of design and landed on something very unique. I used on shape and got 3D models of parts From Grabcad. I then optimized the 3d printed parts for actual ease of printing. From there i started on the documentation creating a spreadsheet for organization and a repository.

2/19/2026 10:40 AM - movement system

For the movement system i decided to use a moving gantry system over a a fixed gantry. to prioritize a lighter system to be able to use lower power steppers while not compromising quality.


The moving gantry is running on MGN12 Linear Rail which was chosen to keep this CNC as rigid as possible well keeping the price low.
The actual moving gantry is run by two Nema 17 motors at a 1 to 3 gear reduction to prioritize rigidness and precision over speed. The gantry moves along a 5gt 20mm wide belt this was inspired by Ivan Miranda CNC machine.
the y-axis runs on 2 MGN12 Linear Rail with the same gear reduction and and 20mm wide belt.

2/19/2026 10:50 AM - Tool head

for the tool head/spindle i decided to use a Makita router because of there availability and price but this was intentionally made to be able to be easily modified to work with virtually any router around the same weight
the z-axis movement uses two MGN12 Linear Rail and a lead screw run by a Nema 17 motor with a 1 to 3 gear reduction. this allows for about 60mm of movement on the z-axis enough for limited 3d milling.

2/19/2026 11:00 AM - Structure

the structure was inspired by Chris Borges 3d printed CNC machine. it uses concrete filled thin walled 3d parts to add weight and structure well keeping prices low. to add more structure for the parts 5/16in threaded rod is rand through the thin walled parts and secured with nuts. the parts thin walls are connected to prevent spreading from the weight of the concrete. this came after a few iterations of printed prototypes. The main structure is made of a single 3dprinted part repeated 14 times with repeated corner pieces to reduce complexity.

2/19/2026 11:19 AM - The brains electronics

for this projects electronics i went with a basic setup a Arduino uno with a CNC shield for simplicity as the shield makes wiring every component relatively easy with built in places for limit switch's. this choice also allows room for improvement over like adding fans for cooling without having to rework all of the wiring.
for software i will use GRBL on the uno and g-code sender to send instructions to the Arduino from my computer.

2/19/2026 11:26 AM - Electronics enclosure

To keep the precious brains alive i designed a electronics enclosure that mounts to the back of the system it holds the power supply Arduino uno and CNC shield along with the emergency stop button. the enclosure is attached with M3 screws and heated inserts.

2/19/2026 11:34 AM - Securing everything.

To secure everything what was mainly used was M3 screws as that was what was compatible with the linear rails i used. To Secure the rails for the moving gantry heated inserts are used but for the y axis t nuts slid into the T-slot extrusion is used.

2/25/2026 - threaded rod, support and structure

the thickness of the threaded rod was increased to 5/16 diameter threaded rod because the previous smaller size was prone to bending and didn't add enough structure to justify using it.
i also began printing and prototyping the structure pieces to optimize strength by print orientation and found for the main body piece it was best printed vertical and that the corner piece would need to be redesigned for more strength and an easier print. i also switched to pla+ for a little more strength faster print times on around the same budget.

3/3/2026 - prototyping

for the correct fit for the nuts to hold the internal threaded rod it took some time and adjustment to get them to perfectly fit in the holes for them. some adjustments were also made to switch plain hex nuts for lock nuts to make sure nothing would loosen during the concrete pour. as well as more prototyping on the corner pieces for the best print orientation for strength.