Installing Pi Zero W on Prusa MK3


LAST UPDATED: 2/11/2018

NOTE: The Raspberry Pi Zero W interface with the Prusa MK3 is still in 'BETA'. There WILL be bugs and possibly failed prints until Prusa Research fixes them as they are discovered. It is HIGHLY recommended that you check Prusa's Driver download page OFTEN to see if new firmware versions have been released for the MK3. 3DKC is not responsible for any issues caused by communication issues between the Pi and the Einsy board. All of our Pi Zero Ws have been pinned out according to Prusa's specifications and all changes to Octoprint made via direct instruction. Please make sure to check the bottom of this page for the latest revisions and changes. Thanks - 3DKC

MK3 Firmware version 3.1.1 has been released. Please update to latest firmware.

SD CARD ISSUE: Please go to the bottom of this page for instructions regarding an issue with the shipped SD Card image.

Link: Prusa Driver Download Page



You're on your way to wireless goodness on the Prusa Research MK3! This guide will walk you through the setup process for your new Pi Zero W. This page will walk those who have already assembled their printer through the process of adding the Pi to the Einsy board. If you haven't received you MK3 yet count yourself at least a little lucky. You don't have to disassemble you electronics compartment! 

A couple of things you'll need:

The Pi Zero W, MK3, Micro SD that came with the kit (If applicable), The Long Allen wrench with the 'ball' end that comes with the MK3 kit.

OPTIONAL BUT HIGHLY RECOMMENDED: A redesigned electronics housing that offers quick access to the Pi once everything is installed. You can print this out of PLA or PETG, your choice. The STL for the new case can be found here:

Huge thanks to Scott Wilkinson for the case design!

Let's get started!


STEP 1: SD Prep

If you bought the complete Pi kit with SD card from 3DKC, take out the Micro SD card and adapter. Plug the Micro SD into the adapter and then the adapter into a PC or MAC. Follow the steps on the back of the Quick Start Guide that came with the kit to set up your wireless network. PROPERLY eject the SD card from your computer and set it aside for now. We'll grab it again in a bit.

If you did not purchase the SD card with the kit, and are providing your own, the custom SD card image can be found at Follow the instructions on that site to setup the image.


STEP 2: Disconnection


Open up the electronics case from the back. Start CAREFULLY unplugging all of the motors, sensors, ribbon cables, etc. Make sure to disengage the locks on the locking connectors. You can leave all of the power connections at the bottom in place. 


STEP 3: Clear the Case

Clip the Zipties that hold the Heated bed cable bundle and the Extruder cable bundle. Move the wires out of the holes in the case and out of the way. 


STEP 4: Raise X Axis

Manually raise the Z axis UP so that the X axis motor is at least 3CM above the electronics case. Feel free to take it all the way up, we just want it out of the way. 


STEP 5: Remove Housing

Using the special Long Allen wrench, with the ball end, LOOSEN the electronics compartment housing mounting bolts. These are the harder to reach bolts that the compartment slips over during installation. If you need guidance on how to reach these please consult the MK3 build guide. There's no need to completely remove the bolts. Just loosen them enough to where the case slides off.


STEP 6: Einsy Removal

Once the Case is clear of the main frame, bend it backwards exposing the Einsy board (it will bend at point of the power wires that are still attached). Remove the 4 bolts that hold the Einsy in the case. When all four are removed, move the case out of the way.


STEP 7: Insert Micro-SD

Remember that Micro-SD card from step 1? Go ahead and insert it into the Pi Zero W (face up). You may need to lift up the printed spacer to help access the port. Once inserted, make sure the spacer is sitting flush against the Pi and that all four spacer pegs are inserted into the holes of the Pi.


STEP 8: Insert Pi into Einsy

MAKE SURE THE PRINTED SPACER IS ON! Line up the Pins of the Pi with the holes on the BACK of the Einsy board. Gently push the pins through the board until the Pi is sitting flush on the back of the Einsy board. If the Pi is hanging over the side, it's on upside down. ;)


Step 9: Optional New Case

If you printed out the modified electronics enclosure (which you REALLY should), then now is the time to get it ready to go. You'll need both the pieces and (2) M4x10 bolts from the SPARE MK3 bag that comes with the MK3.

I HIGHLY recommend printing this case!! SD cards on Pis are notorious for corrupting or failing (Especially if powered down incorrectly). If that happened, and you still have the old case, then you'd have to repeat ALL of the above steps to get to the Pi (or cut up your current electronics case). This new case also has some clearance at the top and bottom of the door to allow a ribbon cable through to attach a Pi Cam.


Step 10: Reattach Einsy 

Reattach the Einsy board into the electronics enclosure (new or old) with the four bolts you removed earlier. You may need to use some pliers to help position the bolts. If you're using the new case remember to grab the four nuts off the back of the old case.


STEP 11: Reattach Case

Bend the case back towards the main frame and slide it on to the two bolts you loosened earlier. Using the long Allen with the ball end, tighten the bolts until the case is snug against the frame. If you're using the new case, there is a slot in the back to gain access to the bottom bolt. Much easier than going through the front on the stock case.


Step 12: Rewire

Using the MK3 build guide as reference, rewire all the sensors, motors, etc back onto the board. Make sure to grab two new zipties to tie down the Extruder and heated bed cable bundles. There should be PLENTY of extra with the kit.


Step 13: Close it up

Close the case back up using the long bolt you took out earlier. NOTE: If you're using the new case, you need to insert and tighten this bolt BEFORE putting the Back Cover on. Tighten until the case is completely closed.


Step 13b: Attach Back Cover

If you're using the new case, attach the back cover on using two of the M4x10 bolts included in the SPARE MK3 bag. 


STEP 14: Power it Up!

Plug the power cable back into the PSU and turn the MK3 on. If everything turns on, that's a good start! Maker sure the Pi is getting power. This is done by blocking any light hitting the back of the electronics enclosure and seeing if there is a green glow on the corner of the Pi. If all is well, proceed! 


STEP 15: Verify/Upgrade Firmware

To utilize the Pi Zero W header on the Einsy board, you need to be running MK3 Firmware version 3.1.1 or LATER. 

To check what firmware is on your MK3, click the menu wheel and scroll down to 'Support'. There you should see the firmware version listed. If you are running an older version, upgrade to the latest version (3.1.1 as of 2/5/2018). You can download both the firmware and updater on Prusa's site:


STEP 16: Selftest

Since we tore apart the electronics compartment and put it back together, it's a good idea to run a Selftest to make sure everything got hooked back up correctly. The Selftest can be accessed via the menu ->Calibration->Selftest. If the test fails, open the compartment back up and verify all connections. Once it completes, then move on.


Step 17: Turn on RPi Port

The Einsy board has TWO main forms of communication: USB and Raspberry Pi header. In order to use the Raspberry Pi Port you have to enable it in Settings. 


Step 18: Disable Crash Detection

One of the cool new features that comes with the MK3 is nozzle crash detection. However, at the time of writing this, crash detection causes issues with communication between the Pi Zero and the Einsy board. So, for at least the time being, it needs to be disabled. To disable it, go into settings and turn Crash det to Off.

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STEP 19: Test Print!

Log in to the Octoprint Web Interface (you need to find the IP address your router assigned to the Pi. You can try accessing the Pi by it's host name 'MK3'. More info about finding the IP can be found in this VIDEO

Once you get logged in, you need to connect to the printer. Everything is pre-configured for the MK3 so you should be able to hit connect and be good. You'll notice there is a test file already loaded. It's just a simple model of the 3DKC logo. It's a good test to make sure everything is running smoothly and that everything is communicating. 



That's It! You now have a web portal for your MK3 and can monitor prints remotely. Feel free to add a camera (Pi cam via ribbon cable recommended. A USB cam may bog down the Pi too much), plugins, and make the Octoprint install yours! If you experience any issues with your Pi, or require the SD card image, please contact

Thanks and Happy Printing,

Joe Mike


1/12/18 - It has been noticed that using Linear Advance with the Pi Zero W may be causing some issues as well. If you experience issues, you may try removing the M900 line from your slicer start G-Code to disable Linear Advance.


1/18/18 - Prusa is about to release RC5 of their firmware for the MK3. Right now it is on their GitHub. Soon it will be on their driver page. This release is being tested and so far seems to have fixed most of the communication issues we've been seeing. If you want to upgrade now, you can download the hex file from their github site and upload it using the firmware updater. 


1/21/18 - RC5 is now up on Prusa's drivers page. Go there to download instead of the GitHub.

SD Card Image Issue - It has been found that the image that comes pre-installed on the shipped SD cards has a problem with the default linux account (pi). This does not affect the usage of Octoprint, but will affect those who wish to SSH into the Pi and use the terminal. The only fix available is to download a fresh (and fixed) copy of the custom image and reflash the SD card. The image link and instructions are coming soon. Sorry for any convenience this may have caused. Stay tuned!


1/22/18 - The Fixed SD Card image is now available for download. 


2/11/18 - Updated site to reflect release of MK3 firmware 3.1.1