Best Arduino CNC Shield – How to Select the Right One

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Do you like to research a product before you buy? If you are like me, I like to know all the details about a given product before I shell out hard earned cash for it. Have you spent time researching the best Arduino CNC shield? Did you find that there seem to be endless options and versions available? The price ranges from ~$10 to over ~$100. What makes one shield worth 10X another?

Well, the following post will help you understand the main options and features to look for when buying the best Arduino CNC shield for your application.

If you already have a Arduino CNC shield and are ready to hoop it up, check out the following link.

Arduino CNC Shield Setup Guide

Overview

There are two main types of Arduino CNC shields.

1 – Integrated Stepper Driver

– The stepper motor drivers are integrated into the shield. To replace the drivers, the chip on the circuit card must be de-soldered and a new one soldered into place.

2 – Modular Stepper Driver

– The stepper motor drivers are modular and plug into a set of headers on the circuit board.

So how do you choose? Let’s take a closer look at what is available to help determine the best Arduino CNC shield for your machine. This is not an exhaustive list.  I tried to capture a wide enough variety of options without creating an overwhelming list.

Image
Name (Link)	Stepoko	gShield V5	Arduino CNC Shield V3.51
Manufacturer	SparkFun	Synthetos	Protoneer
Number of Axis	3	3	4*
Voltage (Volts DC)	12-30	12-30	8.2-45
Current (Amps)	2	2.5	2.2
Modular Stepper Driver	NO	NO	YES
Stepper Driver Chip	DRV8811	DRV8818	DRV8825 (not included)
Maximum Micro Stepping	8X	8X	32X
GRBL Preloaded	YES	NO	NO
Shield Cost	$149.00	$49.99	$20.00
Arduino Cost	$0.00	$19.95	$19.95
	(Included)	SparkFun RedBoard	SparkFun RedBoard
Driver Cost	$0.00	$0.00	$26.85
	(Included)	(Included)	(Price for 3 Drivers)
Total Cost	$149.00	$69.94	$66.8

Stepoko Board image from SparkFun used per CC BY 2.0

The table above provides a quick summary of the features and benefits of each solution.

How to Choose the Best Arduino CNC Shield

Here are some key questions to ask yourself that will help you pick the best Arduino CNC shield…

1.   How many stepper motors do you need to control?

a.   3 or fewer, any of the options below will work

b.   4 then you will want to choose the CNC Shield 3.51 from Protoneer

Note, this is not 4 axis, just 4 stepper motors. This is good for the case where you have a CNC router and need dual motors on a single axis. GRBL only supports 3 axis control at this time.

2.   Are you comfortable loading software on to an Arduino?

a.   If you are then either the gShield or CNC Shield 3.51 will work

b.   If you don’t want to mess with software then you can go with the Stepoko

3.   If cost is your most important factor then the CNC Shield 3.51 is your best bet.

 

Now let’s talk about each option in detail

The details…

Note, I receive a small commission if you purchase the SparkFun Redboard through Amazon. The price you pay does not change. If you would like more information click here to read my affiliate disclosure.

Stepoko from SparkFun

              Pros:

– Pre-loaded GRBL software! This is the only option of the three that does not require software to be loaded onto the board. If the idea of loading software onto an Arduino is holding you back, this is the option for you.

– All in one solution includes the Arduino & stepper motor drivers

– Screw terminal connections for stepper motors & limit switches

Cons:

– Price at $149.00 it is the most expensive of the three solutions

In the interest of full transparency, I have never used this board, so my knowledge is limited to what I have read form the manufacturer and comments from users.

Click Here to get the Stepoko from SparkFun

gShield from Synthetos

             Pros:

– Vast user forum and knowledge base

– Includes the stepper motor drivers

– Screw terminal connections for stepper motors

Cons:

– Includes the stepper motor drivers

You are probably wondering how can “Includes stepper motor drivers” be both a Pro and a Con? Well I like the fact that I didn’t have to figure out which stepper motor driver to buy or how to install them.

The down side is if you damage one of the stepper drivers, you will need to do some careful de-soldering and re-soldering of the driver chip or return the board to Synthetos.

Why did I choose the gShield from Synthetos?

First, I really liked the craftsmanship of the board. It looks really clean. Synthetos appears to pay attention to details. They also have a forum on their site to help answer user questions.

Second, I was drawn to the simplicity of the gShield. Everything is right there. No need to order additional stepper drivers and figure out how to install those or decide which drivers to order. Fewer decisions and a confidence that the board would work when it arrived. I would not need to spend time debugging a circuit card assembly.

Third, cost, once you factor in the additional cost of the stepper drivers, the price was not a major factor.  Just a few dollars different.

Finally, I already had an Arduino and when I bought my equipment back in 2015 this seemed like the most popular option.

Click Here to get the gShield from Synthetos

Click Here to get the Sparkfun Redboard

CNC Shield 3.51 from Protoneer

              Pros:

– Option to drive 4 stepper motors. If you are building a cnc router that needs two motors for say the x-axis, this is the solution for you.

– Ability to choose the stepper motor drivers

– Low cost

Cons:

– Not fool proof, stepper drivers can be installed incorrectly

– No screw terminals for stepper motors, just header pins

Again, in the interest of full transparency, I have never used this board either, so my knowledge is limited to what I have read form the manufacturer and comments from users.

However, this will likely be my next setup since I want to build a CNC router and the option to have dual motors on one axis is really appealing.

Click Here to get the CNC Shield 3.51 from Protoneer

Bonus – TinyG from Synthetos (non GRBL, 6 Axis Option )

 

All of the options we have discussed thus far run the open source gcode interpreter GRBL on the Arduino. However, I would be remiss if I failed to mention a non GRBL option.

The TinyG from Synthetos is an option if you need more than 3 axis. This runs custom firmware that interprets the gcode sent via USB to the board. These devices can be networked to control up to 1000 stepper drivers. The TinyG supports 6 axis control (X,Y,Z,A,B & C). All of this performance packed into a package that cost just $129.99

Again, I have never used one of these boards, however, it looks like a great option for machines that require at least 4 axis motion control.

Conclusion

This would be a much easier post to write if there were a clear answer for the best Arduino CNC shield. I could just say go buy this. However, its not that simple. Each option may be better suited for a given application.

In any case, we get a sweet motion control system for less than $150 US. In my mind that’s amazing.

Once you have your GRBL based Arduino CNC shield, head over to the page where I walk through the process of setting up your DIY Arduino CNC Controller.

What is your preferred solution? Comment below with your choice for the best Arduino CNC shield.

Thanks for reading. Until next time… Tim