Hi everyone.

I consider that CNC machines are useful tools which allow you to make high precision things that handmade would be way difficult. So a year ago, my father and I started this project in order to built a CNC as cheaper as possible, also with enough precision to "print" a PCB. This is the result.

It've been developed with simple electrical tools, i think the most complex instrument I used was a pillar drill.

This machine is based on Arduino with GRBL firmware and it's compatible with Easel, an awesome tool from Inventables that let you design easily and fast a project for CNC.

So let's get started.

Step 1: Bill of Material

I've bought most of the things in Banggood. Although you can find the same materials with a lower price on another places on the internet, like Ebay.

You might also find in the Excel file more detailes about the billl: the quantity of things, or some kind of especification.

In the first photo, you can see four Lead Screw, but finally it's only neccesary three.

In this project, the shield that i used it's a own design, I explain later, in the electrical step but if you don't have experience making PCB, I recommend you to buy a shield compatible with GRBL like this one:

Shield with drivers and arduino

BOM.xlsx
Download

Step 2: BluePrint

These blueprints can be opened with Autocad or any DWG viewer.

The first file is a 2D blueprint of MDF parts of the machine which shows the distance beetween the drill holes. All the drill holes are 8 mm diametre.

The second file is a 3D model of the machine. In order to know where is the parts.

Step 3: Building

I've uploaded a few images of the building process. I recommend constructing it in the order that the images appear, Due to the fact that I think it's the easiest way to build it.

In the blueprints I didn't show any screw holes, because after I built it, I thought it was better to use hot glue or Pattex Power Lijm than glue bearings to the structure.

I believe it's a better way, because it's easier to use and the structure goes to their natural place.

Step 4: Shield ,wires and Motors

In this machine, I have put a shield that I designed by myself. It has some special features like a port for heigh probe and cooler. But also you can buy a commercial one, just like I've put on the bill of materials.

The only necessary:

Arduino(Uno or Nano ).
3 Drivers A4988.
3 Motors Nema 17
12v 5A voltage supply(the machine needs around 2.5A
A lot of wire.(well around 5 mtr will be enough)

Basically, the wire connection is like in the diagram from the last imagen but with three motors.

I recommend using tubes for wire and clips to have organised the wires, because sometimes It can be a little difficult to know where does the wires come from.