These instructions assume the software will run on a Raspberry Pi computer in conjunction with OctoPrint. It is recommended that a Raspberry Pi 2, 3, or 4 computer be used as the host machine (see the FAQ for other machines).
Prepping an OS image¶
Start by installing OctoPi on the Raspberry Pi computer. Use OctoPi v0.17.0 or later - see the octopi releases for release information. One should verify that OctoPi boots and that the OctoPrint web server works. After connecting to the OctoPrint web page, follow the prompt to upgrade OctoPrint to v1.4.2 or later.
After installing OctoPi and upgrading OctoPrint, it will be necessary to ssh into the target machine to run a handful of system commands. If using a Linux or MacOS desktop, then the "ssh" software should already be installed on the desktop. There are free ssh clients available for other desktops (eg, PuTTY). Use the ssh utility to connect to the Raspberry Pi (ssh pi@octopi -- password is "raspberry") and run the following commands:
git clone https://github.com/Klipper3d/klipper ./klipper/scripts/install-octopi.sh
The above will download Klipper, install some system dependencies, setup Klipper to run at system startup, and start the Klipper host software. It will require an internet connection and it may take a few minutes to complete.
Building and flashing the micro-controller¶
To compile the micro-controller code, start by running these commands on the Raspberry Pi:
cd ~/klipper/ make menuconfig
Select the appropriate micro-controller and review any other options provided. Once configured, run:
It is necessary to determine the serial port connected to the micro-controller. For micro-controllers that connect via USB, run the following:
It should report something similar to the following:
It's common for each printer to have its own unique serial port name. This unique name will be used when flashing the micro-controller. It's possible there may be multiple lines in the above output - if so, choose the line corresponding to the micro-controller (see the FAQ for more information).
For common micro-controllers, the code can be flashed with something similar to:
sudo service klipper stop make flash FLASH_DEVICE=/dev/serial/by-id/usb-1a86_USB2.0-Serial-if00-port0 sudo service klipper start
Be sure to update the FLASH_DEVICE with the printer's unique serial port name.
When flashing for the first time, make sure that OctoPrint is not connected directly to the printer (from the OctoPrint web page, under the "Connection" section, click "Disconnect").
Configuring OctoPrint to use Klipper¶
The OctoPrint web server needs to be configured to communicate with the Klipper host software. Using a web browser, login to the OctoPrint web page and then configure the following items:
Navigate to the Settings tab (the wrench icon at the top of the page). Under "Serial Connection" in "Additional serial ports" add "/tmp/printer". Then click "Save".
Enter the Settings tab again and under "Serial Connection" change the "Serial Port" setting to "/tmp/printer".
In the Settings tab, navigate to the "Behavior" sub-tab and select the "Cancel any ongoing prints but stay connected to the printer" option. Click "Save".
From the main page, under the "Connection" section (at the top left of the page) make sure the "Serial Port" is set to "/tmp/printer" and click "Connect". (If "/tmp/printer" is not an available selection then try reloading the page.)
Once connected, navigate to the "Terminal" tab and type "status" (without the quotes) into the command entry box and click "Send". The terminal window will likely report there is an error opening the config file - that means OctoPrint is successfully communicating with Klipper. Proceed to the next section.
The Klipper configuration is stored in a text file on the Raspberry Pi. Take a look at the example config files in the config directory. The config reference contains documentation on config parameters.
Arguably the easiest way to update the Klipper configuration file is to use a desktop editor that supports editing files over the "scp" and/or "sftp" protocols. There are freely available tools that support this (eg, Notepad++, WinSCP, and Cyberduck). Use one of the example config files as a starting point and save it as a file named "printer.cfg" in the home directory of the pi user (ie, /home/pi/printer.cfg).
Alternatively, one can also copy and edit the file directly on the Raspberry Pi via ssh - for example:
cp ~/klipper/config/example-cartesian.cfg ~/printer.cfg nano ~/printer.cfg
Make sure to review and update each setting that is appropriate for the hardware.
It's common for each printer to have its own unique name for the
micro-controller. The name may change after flashing Klipper, so rerun
ls /dev/serial/by-id/* command and then update the config file
with the unique name. For example, update the
[mcu] section to look
something similar to:
[mcu] serial: /dev/serial/by-id/usb-1a86_USB2.0-Serial-if00-port0
After creating and editing the file it will be necessary to issue a "restart" command in the OctoPrint web terminal to load the config. A "status" command will report the printer is ready if the Klipper config file is successfully read and the micro-controller is successfully found and configured. It is not unusual to have configuration errors during the initial setup - update the printer config file and issue "restart" until "status" reports the printer is ready.
Klipper reports error messages via the OctoPrint terminal tab. The "status" command can be used to re-report error messages. The default Klipper startup script also places a log in /tmp/klippy.log which provides more detailed information.
In addition to common g-code commands, Klipper supports a few extended commands - "status" and "restart" are examples of these commands. Use the "help" command to get a list of other extended commands.
After Klipper reports that the printer is ready go on to the config check document to perform some basic checks on the pin definitions in the config file.