Picture of Arduino Controlled CNC / 3D Printer Hybrid

Mother Nature Makes ... We Build.

BuildersBot Fuses 3D Printing & CNC Milling Into One Builder’s Dream ""

The BuilderBot is an Open Design machine, that uses Open
Software and Open Hardware. It is a product of open projects such as the RepRap, Arduino and Repetier .

The objective of this instructable is to guide your way throw the entire making process of building a BuildersBot machine. An open design Arduino Controlled CNC Router that can also perform 3D printing.

The instructions will cover all areas such as design, mechanics, electronics and software.

But before you go any further take a look at machine's concept design:

And also the machine build photos and the machine in action:

Finally check out the insane effects of the RGB led's on BuildersBot:

Warning Viewer Discretion Advised (Strong Language)

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Step 1: The BuildersBot OpenDesign (Sketchup)

Picture of The BuildersBot OpenDesign (Sketchup)

To view the the machine in 3D just Download the attached sketch file and access the BuildersBot OpenSource Design (in metric system and is in 1 by 1 scale).

Use this design as much as possible for guidance during this instructable.

NOTE: Use trimble/google sketchup to open the file.

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Do you have a photo of where the 12v power supply fits in the case?

aldricnegrier (author)  pcourtemanche9 days ago


The 12V power supply fits under the micro stepping drivers, on the base of the case, with the connections pointed towords the acrylic door.

As soon as i can i will take a photo for you to see.

aldricnegrier (author)  aldricnegrier9 days ago

if you look closer. you can see the 12V power supply under the microstepping drivers. The Arduino is on the wall of the acrilic side plate.

benouville10 days ago


Thank you for you work, it's useful! I'm curently building a 4 Axis foam cutter CNC. Therefore I considering Malrin or Repetier for the firware (+ramps1.4, arduino mega 2560 and drv8825 drivers), but I have no idea if it is possible to configurate the A axis the same way as for X,Y,Z (meaning entering step/min, ect..) Especially, I'm wondering if it's possible to implement endstops for the A axis ? (normally they are firmwares for 3D printing and A axis is the extruder so usually, it doesn't need any endstops!)

I hope I'm being clear, thanks for your help !!

PS: I should add that I'm a rookie in electronics and code!

aldricnegrier (author)  benouville9 days ago


I dont know if it would work with repetier or marlin firmware, it would be a great hack if it could :)

You would have to try it out to find out if it is possible.

Love the machine ! Looks strong and powerful. What speeds can you reach during 3D Printing ? (while conserving a good print quality of course)

aldricnegrier (author)  Get3DPrinted9 days ago


The machine has a lot of mass on the X axis, so you need to go slow to avoid inertia problems, i don't remember the settings but it should be around 30-50mm/s.


Can I use Nema 17 for make a 3D printer ?

aldricnegrier (author)  emile.renaud.311 days ago

Hello Emile,

Yes you can, NEMA 17 is a common motor for 3D printers.

You should star by visiting the "reprap" website.



Hello, which type of bits are used for wood and aluminum.

aldricnegrier (author)  ankitvaid199013 days ago


2 flute carbide end mill

jpmasse317 days ago


I have been working on building the printer/CNC. I've been able to salvage some stepper motors I have had laying around but they are giving me nothing but issues. Can you give the model number for the steppers you used?

aldricnegrier (author)  jpmasse313 days ago

4 Nema 23 Stepper Motors with 425oz-in holding torque

4 Stepper Drivers with 4.2A DQ542MA

2 Power Supply for 350W,36VDC

aldricnegrier (author)  jpmasse313 days ago

Make sure you are sending the right amount of current to the motors. If the current is not right, the motor will not step. Check the datasheet of the mortors and the drivers. I used NEMA 23 425 oz/in torque.

Hello. I'm going to build this machine, but only for CNC milling at first. I plan to use the small dremel or even the flex one that comes with it. Is it ok to use the Nema 17 step motors? I've already 4 of them, of 4.5/torque with their A4988 step motor driver, Arduino Mega and RAMPS 1.4.

Do you think it will be fine with this components? Also, to make it only for CNC Milling, what configuration should I set in the repetier configuration.h file to remove the 3D printing features? Thank you!!

NEMA 17 - 4.5kg/cm

NEMA 23 - 30.6kg/cm (Buildersbot)

I don't know if it will work with NEMA 17, i never built a CNC with NEMA 17.

Regarding, repetier, default settings will work fine. You just need to adjust the workspace, and the steps per mm of your motors*microstepping.

mellontiko22 days ago

Hi Aldric!

How do you stretch timing belts? Ι have enough oscillation

aldricnegrier (author)  mellontiko19 days ago

If you cant get good tension on the belts you have a look at these solutions:

I have good tension, but with time the tension gets week, and i need to tighten it again, so i found this nice solution that i will try to implement:

aldricnegrier (author)  mellontiko22 days ago

Hi Mellontiko,

You need 1 more person to help you tighten the belts. I can do it by my self now that i have some experience.

I do it by my self using a rope on the small pulley shaft, lock the belt in place, and using the rope stretch the small pulley shafts into place using the rope.

It is a bit hard to explain.

After you do this you can put a tensioner on the belt, for extra tention.


Do you suggest any e-shop to find this article?

Actually im using a 16mm wide belt....

aldricnegrier (author)  mellontiko21 days ago

Mine are 15mm, i got the item off a pair of clothe pegs, not your regular clothe peg (they are too small), i found nice strong ones in a dollar store.

Just have a look in a dollar store to find big cloth pegs.

Keep in mind, you need to tighten the belts first by hand, strong and tight, then you attach the pegs. Just using the pegs wont do you any good, if the bets are not tightened.


Hi, I am having CNC milling machine. I am planning to convert it into a 3D printer. I am going to use a quad extruder, I am looking for a control board for the quad extruder, can you please help me?

aldricnegrier (author)  ragav.ramesh.922 days ago

Hello ragav,

I dont know, i dont have experience with multiple extruders. Sorry.


I have a Prusa I3 3D Printer which use Arduino Mega 2560 and Dremel with Flexible shaft. I want to convert my 3d printer to cnc router as you told on step 17 I Configuring the Repetier Firmware for CNC functionality,

But i don't know how to generate g-code from STL , DXF or any other image file(SVG) to use with these type of cnc router.

aldricnegrier (author)  ankitvaid199024 days ago

Hi ankitvaid,

You need to use a CAM software.



mellontiko what is the manufacturing cost ?

dj_freakout26 days ago

Hi Aldric :) thank you for the help so far, in the 15th page you said that the precision will b calculated later, have you done it? could you tell us what it is?

Thank you :)

maddig1 month ago

Hello Aldric, thank you for this fantastic guide! I have a question for you. At the base frame, should I take the measurements from SketchUp or from the manual? In the manual, the lengths of the upper frame are indicated with 750mm, but when I take a measurement in Sketchup there are two 760mm and one 720mm piece. I hope you can help me. And sorry for my bad english, I'm from Germany.

aldricnegrier (author)  maddig1 month ago


Follow the sketchup file, i am sorry for the mistake.

I will correct it as soon as possible. Thank you.

aldricnegrier (author) 1 month ago

Check out the Buildersbot in action:

derah041 month ago
AliGee1 month ago

Hi, I try to build a similar project in a little bit bigger workspace size (1200x1000mm). Now I'm looking for the right motor sizes (Nema 23 / 34).

My problem is that I don't know what motor torques are needed for a 20mm miller (for wood) and the right accelerations of the x and y axes for 3D printing.

Why did you choose this kind of motors and how much micro steps you use? Are you satisfied about your 3D printed objects quality or resolution?

A video about workspeed milling/printing would be very nice to suggest how fast it works.

Sofiadelfi1 month ago
La cama caliente para la impresora 3d se puede tener una medida de 800x800milimetros
aldricnegrier (author)  Sofiadelfi1 month ago

Yes it can. Just scale it that way.

dj_freakout1 month ago

How many amps for the 36V power supplies each?

aldricnegrier (author)  dj_freakout1 month ago

Power supply-----350W--36V, 9.7A

Hi aldricnegrier,

can I know as to where you connected the LCD display?

Does the Ramps 1.4 Breakout Board support the SD card system out of the box?

aldricnegrier (author)  dj_freakout1 month ago

Yes it does, it supports LCD and SD card.

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