Monday, December 7, 2015

Wiring Your Own CNC. Yes It IS That Stupidly Easy

There are plenty of dedicated shields and boards on the market to set up our machine. 

Some are harder to figure out than others.  I only wish I had the benefit of these diagrams when I started this adventure a couple years ago.

First of all we will start with the board.

You can build it on the Arduino UNO board.  I just checked and the price for the original Ardunio (not China clone which I will explain why later) and it is $27USD delivered to my door here on the tropical island.  That includes shipping, customs and overnight air freight.

Pretty basic stuff.

Next you need to flash the firmware on the thing.

Get the firmware here for the GRBL controller

Home · grbl/grbl Wiki · GitHub
Aug 17, 2015 - Please feel free to modify these pages to help keep grbl up-to-date! ... retained between different versions of Grbl as you upgrade the firmware.
Configuring Grbl v0.9 - ‎Compiling Grbl - ‎Connecting Grbl - ‎Interfacing with Grbl

You will have to follow the instructions to upload it but it is pretty simple.

Unzip the firmware folder and open the main file in Arduino.  Do not worry about all the other files they will all open at the same time.

Here is the Arduino software


Arduino IDE that can be used with any Arduino board, including ...

You select the type of board you got in the menu.  For this tutorial it is Arduino Uno and the com port.  This is the same as selecting the com port for a paper printer.  No biggie.

Now you need to get something called a stepper driver.  Actually 3 of them.

What the board does is send signals over 3 wires to the stepper driver that amplifies the power and drives a motor.  The stepper motor is basically 2 DC motors inside one case.  But right now you dont need to know much more than that.  All you need to know is that there are 2 sets of wires. to each motor.  The trick is to make sure that you are not wiring it up so one motor pushes against the other or it will not work.

Here is an example of a dead simple stepper motor driver.

Ok now it is 3 wires from the board to the driver.  Some require 4 wires and there are 4 wire inputs but for this setup it is just 3 wires.

Here is how you wire it up

On the other side of the board there are 4 wires.  A+ A- B+ B- and power supply.  For this driver you can use anywhere between 12 and 36 volts.  I use 24v.  10 amp power supply at 24v is $30.  Now you can hack an old laptop power supply like one of those 19v ones or 21v supplies and it will also work provided you can get enough amps out of it.

Now you got that done and your motors hooked up, here is the software:

Grbl Controller - ShapeOko
Apr 13, 2015 - Grbl Controller 3.6.1 for Mac, Windows and Linux - by Zapmaker ... Grbl Controller is a piece of software which is used to send GCode to CNC

And there you go.  2 years of study boiled down to one blog post.

Obviously you will have to read the info at the links provided.

Now you can build a precision machine and use that to make your own mischief and mayhem.

Side note:

You should get the original Arduino instead of the Cheap China clones not because they are pirated.  They are not cause Arduino is open source.  It is because often times China boards use a counterfeit USB driver chip and the standard windows drivers will not work with it or will work one day and not the next.  All to save a few cents for the original chip that is not open source.


Lew Heifner said...

This is great information, thanks.

Anonymous said...

Can you flesh out some applications for this thing?

What's involved in the programming the final machine instructions for an application?

Tucanae Services said...

Sadly, it appears access to the GRBL code is disabled on S3.

Anonymous said...


Please elaborate...

Anonymous said...

While the download links to the Amazon S3 servers are broken, it appears that both the source code and pre-built executables are still available on github: