If you are building a CNC router or converting your manual machine to CNC, setting up the electronics involved in controlling the machine can be overwhelming.

This is where the Buildbotics controller steps in as a powerful plug-and-play solution for controlling your CNC router.

With a raspberry pi at its core, it offers some unique features not found in most other CNC controllers.

In this article, I talk about the features, specifications, advantages, and limitations of the Buildbotics Controller.

Buildbotics Controller Review

Buildbotics controller was developed by two CNC enthusiasts as an open-source project to support the DIY CNC community.

Buildbotics is an all-in-one solution that has a controlling computer, controller, and stepper motor drivers packed into one neat sleek looking enclosure. 

As it is an open-source project, you get a quicker resolution to errors and faster upgrades and updates compared to other non-open-source builds.

I reviewed the controller for its compatibility with motors, build quality, features, ease of use, and customer support.

Price

This advanced CNC controller costs ~$499 + Shipping, and is available for purchase from the Buildbotics store.

What you get for this price is:

• Controller (plug-and-play)
• Logitech Gamepad for jogging
• DB25 breakout board

Now, unlike many controllers, the stepper drivers are included within the controller, saving you that cost.

Also, you don’t need a dedicated computer to operate this controller. You only need to supply a monitor, mouse, and keyboard to this controller.

If you don’t have a spare desktop PC lying around, this feature alone will save you a few hundred dollars.

You’ll also need a power supply unit for the controller and stepper motors. Buildbotics offers two Meanwell power supply units at a price of around $60 and $120, you can add them to your purchase from their official store.

I’ve done a price comparison of running a CNC using Buildbotics controller with that of other popular controllers later in this guide.

Stepper Motor Compatibility

With Buildbotics, you can drive up to four stepper motors that require a 24 – 48 V supply. The first version supported up to 36 V, but now there have improved the power supply to support a maximum of 48 V.

The controller can supply a maximum current of 6 A to each motor.

This means you can use most NEMA 17 and 23 stepper motors, some NEMA 34 stepper motors, and any other stepper within a 48V 6A rating.

The drivers used are based on Texas Instrument’s DRV8711 stepper drivers and are embedded onto the main PCB.

This means if you burn one of the stepper drivers, it is quite difficult to repair. You’ll have to desolder the SMD driver chip and solder in a new one.

However, the controller comes with several protection features to prevent damage due to power surges or over heating.

The drivers support 256 micro stepping and S-curve acceleration. S-curve acceleration is a great feature that prevents jerks that occur when the motor starts and stops.

This allows your CNC to run smoother and retain its precision for longer.

Furthermore, the controller is capable of sending 2,50,000 pulses per second. This means it can tell the stepper motor to turn 2,50,000 times in a second, making it really fast.

Buildbotics provides four 10-foot-long cables to connect the motors that you can plug into the four motor ports at the back of the controller.

Axis Support

Buildbotics controller has full four-axis support.

It can drive four axes independent of each other or it can drive three linear axes and drive a fourth rotary axis.

Contrary to this, popular GRBL based controllers by design can only drive up to three axes, so this is definitely a step up.

Additionally, the rotary axis support allows you do CNC turning to make products like chess pieces, and pens.

External Device Support

The back panel has ports to connect four 4-wire stepper motors, an HDMI port for the monitor, four USB ports, one ethernet port, a DB15 port, a DB25 port, and a power supply port.

All of the devices on the CNC router side are connected through a breakout board that plugs into the DB25 connector on the back of the controller.

The DB25 breakout board adapter is provided along with the controller. 

The DB15 port is a dialed-down version of the DB25 port and has step and direction output for the four motors, along with a 0-10 V pin for spindle control.

Limit switches

The breakout board has eight terminals to connect limit switches.

Typically, most similar controllers support three-axis limit switches but the Buildbotics controller has limit switch support for four axes.

Height Probe

You can connect a Z-axis probe to the controller via the DB25 breakout board and automate zeroing the Z-axis.

E-stop

The breakout board has a pin where you can connect an E-stop button for stopping the machine in case of emergencies.

0-10 V Spindle

It has a 0-10 V output that you can use to run a simple DC spindle. Such spindles are usually used for engraving and PCB making.

PWM Spindle

The breakout board has a PWM pin that you can use to connect to a laser module or control a low-powered spindle.

VFD Spindle

The controller board comes with an RS485 chip that you can use to communicate with VFD controllers.

You can connect the VFD to the controller via the breakout board and use the control software to control the speed and torque of the spindle.

Analog Output

There are two analog output terminals that can supply a 0 – 10 V signal to control an external accessory that you may use.

Digital I/O

The DB25 adapter has two digital input/output pins that you can use to turn on/off other devices like coolant pumps or dust collectors.

USB Camera

There are USB ports at the back and you can plug in a USB webcam to monitor the cutting process remotely.

You can add it to your controller purchase on the official website at an additional cost.

Gamepad

You can hook up a USB gamepad with the controller and use it to jog and control your CNC router manually.

Buildbotics provides a gamepad with the controller at no additional cost.

External Motor Drivers

If you want to use your own stepper motor driver Buildbotics allows you to do that.

The DB25 port has eight pins that put out the step and direction signal for the four motors.

You can connect your stepper motor driver to the DB25 breakout board and use Buildbotics as the controller.

Build of the Controller

This is one of the areas that the Buildbotics controller is extremely good at.

All the components are neatly packed inside a sleek-looking enclosure.

The enclosure has a footprint of 6.3” x 6.1” x 2.8” and has slots that you can use to mount it onto your CNC machine.

Its design makes sure that there are no shock hazards.

The enclosure has no cooling fans which can be a bad thing, but when you need to use it in dusty environments having a cooling fan will fill the enclosure with dust.

Furthermore, the controller has temperature protection built-in, so you don’t have to worry about cooling fans.

The front panel has an LCD display and power switch and all of the ports are provided at the rear end of the controller.

The Controller

You do not require a computer to control your CNC router if you are using the Buildbotics controller.

The controller has a Raspberry Pi 3 inside with a 16 GB SD card and runs Raspbian Linux OS which acts like a computer.

Additionally, it has an AVR ATxmega192a3u microcontroller that controls the stepper motor drivers.

Using an additional microcontroller to generate pulses for the motor takes the load off of the Raspberry Pi computer and makes more room for processing other things.

Although the microcontroller is an 8-bit one that cannot offer very high pulse rates, the guys at Buildbotics hacked it to produce pulses at 2,50,000 per second.

The fast pulse rates help you achieve really good cutting speeds and bring down cycle time.

You take the G-code from your CAM software and open it up on the controller interface, the inbuilt controller software that runs on the Raspberry Pi 3 reads it and processes it.

It then instructs the AVR processor, which then converts it into step pulses and direction signals and sends it to the stepper drivers.

The stepper drivers then run the motors to move the axes in the programmed direction.

There are four USB ports and one HDMI port at the back of the controller.

You can plug in a monitor to the HDMI port and plug in a mouse and keyboard to control your CNC router.

The controller itself has an LCD screen on the front panel that shows information like, status, temperature, current coordinates, and errors.

All the inputs are protected against high currents which prevents damage to the controller due to excess current from input devices.

Power Supply

Buildbotics offers two power supply units that you can choose from. Both of them are from the popular power supply unit maker, Honeywell.

One is a 280 Watt unit and the other is a 350 Watt unit. Choose the one as per the stepper motors you choose.

Connectivity

You can connect the controller to your computer using an ethernet cable and use any web browser to access the control software.

Alternatively, you can connect the controller to your WI-Fi network and use any device with a web browser connected to the same network to access the controller.

Yes, on any device, you can use your smartphone, laptop, or tablet to control your CNC machine. 

There is no limitation on the OS that you need to use. As long as the device has a web browser, you can connect to the controller.

Software 

The Raspberry Pi 3 board runs on Linux Debian OS which is light and fast.

The control software comes pre-installed on the Raspberry Pi board on the controller. The control software interface is similar to cncjs GRBL controller software and works in a similar way.

You can access the interface through any web browser on any device connected to the same network as the controller.

It has a minimalistic and neat layout, that is easy to learn and use.

Even though the controller does not work on the GRBL firmware it uses standard G-code to control your CNC router.

The firmware used on the AVR controller is a custom-built one made using Python. It has full four-axis capability.

The control software works with most of the popular CAM software like Fusion 360. Additionally, it can display a 3D visualization of the cutting process.

You can use CAMotics software to check whether the G-code from your CAM software will work with Buildbotics.

It is a free software and you can expect quick feature updates as it is an open-source software.

Furthermore, it comes with several presets to make your job simpler. You can also use macros to map buttons to G-code that you need to use frequently.

The controller software also allows you to edit the G-code from its interface without having to go back to the CAM software and modify it and copy it all over again.

CNC Applications

Buildbotics controller can be used for any of the CNC applications like lathes, mills, routers, plasma cutters, and lasers.

It has been tested with some of the popular machines out there. Here is a video of an Ox Router with a Buildbotics controller that does an incredible 2750 ipm rapids.

Buildbotics controller is also tested with popular CNC mills and CNC lathes such as Taig and Sherline.

So, there is no question that the Buildbotics controller can handle any of the CNC applications you throw at it.

If you are wondering whether it can handle some 3D printing, it can, theoretically. But practically, there are other purpose-built controllers for 3D printing.

CNC Retrofitting with Buildbotics

Buildbotics is a great choice for a controller if you want to convert your old manual machine into a CNC machine, be it a router, mill, lathe, or laser cutter.

Buildbotics controller has been successfully used with several popular machines out there like Taig mill, Ox router, Dyna Myte 2400 CNC mill and they also have a guide on using it with the K40 laser cutter.

If you want to retrofit your machine, you can expect a lot of help from the team at Buildbotics.

Buildbotics also offers documented case studies of successful retrofits done with their controller.

Assembly

The controller comes fully assembled and is a plug-and-play solution. There is no software installation required.

All you need to do is connect your motors using the cables provided, wire up the DB25 breakout board, plug in the power supply and you are ready to go.

Community and Support

Buildbotics has a large community of users evident from the active forum page that they run.

There are several videos and blogs that detail configuring the Buildbotics controller with various CNC routers and peripherals.

You can be sure that you will find enough resources online to get you through any difficulties you may face while setting up the Buildbotics controller with your build.

Alternatively, you can contact Buildbotics via phone or email for a quick and reliable response to your queries.

There is no formal warranty for the controller. However, Buildbotics provides a 60-day money-back guarantee.

You can return the undamaged controller if you are not 100% satisfied and receive a complete refund of the purchase price.

Buildbotics vs Blackbox vs Ethernet SmoothStepper

	Buildbotics	Blackbox	Ethernet SmoothStepper
Price	~$499	~$199	~$199
Stepper Drivers	48 V, 6 A	24 V, 5 A	None, need additional drivers
No. of axes	Four	Three	Six
Software	Free Custom software	Free Custom Grbl software	Mach 3 or Mach 4 (paid)
Controller	Inbuilt Raspberry Pi 3 computer	Needs additional PC	Needs additional PC

Comparing the price Buildbotics is the clear winner.

Let’s say you use ESS, to achieve four-axis motion control you will also need a four-axis stepper driver.

You may use the Gecko G540 but even that is not as powerful as the drivers on Buildbotics and costs around $270.

Then you’ll need a dedicated computer to run the Mach control software which will cost you another $150 at least. Mach 3 software costs around $175.

That takes the total cost for controlling to around $795 if you use ESS.

In the case of Blackbox, the drivers are nearly half powerful as the drivers on Buildbotics and it can only support up to three axes.

Once again you need to factor in the cost of a dedicated PC to control Blackbox and the cost goes up to $350 for a three-axis control solution.

The price comparison is without factoring in the cost of power supply units for any of the controllers.

If your power demands are less and you only require three axes you can go for the Blackbox controller. However, you’ll miss out on the ability to upgrade to a better machine as your demands grow with time.

You will have to purchase a new controller to upgrade to more powerful components, probably Buildbotics?

Buildbotics supports 1/256 microstepping and Blackbox supports only 1/32, on the other hand, the microstepping capability of ESS depends on the stepper driver that you use.

Blackbox and ESS are not dustproof by design and you need to protect them from dust, whereas, the Buildbotics controller is sealed and has no trouble working in a dusty environment.

Furthermore, Buildbotics control software has several features like 3D visualization and the ability to edit G-code which makes it superior to the control software of the other choices.

Additionally, you do not require a dedicated PC if you are using Buildbotics and you can view and control your CNC cutting even from a smartphone.

The gamepad controller and USB camera monitoring are features that you won’t find in any other controllers.

The additional rotary axis support on the Buildbotics controller lets you expand the capabilities of your CNC router to work on cylindrical workpieces that the other controllers do not support.

If you are planning to operate a CNC lathe, plasma, or anything other than a CNC router/mill, GRBL and Mach3 are often poor solutions.

Buildbotics shines here, being well-equipped to handle a variety of CNC applications.

Final Thoughts

The Buidbotics controller is a robust and reliable choice for controlling your CNC machine. It can control up to four axes along with support for a rotary axis.

All of the components are packed inside a sleek and sturdy enclosure that allows you to use it in dusty environments making it a good choice for woodworking.

It has multiple safety and convenience that give you a bang for the buck and provide you with a no-fuss solution to control your CNC router.

The customer support and community support are really great which makes using the controller an easy-to-do task.