KliPiNP is a unique blend of Klipper firmware with OpenPNP, aimed at optimizing the functionality and adaptability of pick-and-place systems.
The rationale behind KliPiNP hinges on several key technical insights:
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Uncharted Territory: No one else has married Klipper's firmware capabilities with OpenPNP's handling precision in this way before. KliPiNP aims to set a precedent, creating a new standard for what open-source hardware can achieve in automated systems.
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Comfort with Klipper: The decision to utilize Klipper stems from a deep familiarity with its ecosystem. This comfort level allows for a more intuitive setup, quicker troubleshooting, and smoother operation overall.
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Config on the Fly: Klipper excels in allowing users to tweak and adjust settings without the downtime of reflashing firmware—crucial in an environment where quick adjustments can be the difference between an optimal or subpar performance.
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Mechanical Smoothing: The project uses a Lumen style frame, a low cost flexible Pick and Place platform. Klipper's input shaper comes into play here, effectively dampening any frame-induced vibrations or noise, thus ensuring high precision without the need for heavy-duty frame enhancements.
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Macro-based Simplification: The use of Klipper macros significantly streamlines the kinematic setup. For example, integrating a 'HOME-ALL' macro means homing becomes a one-command operation in the system. This simplicity extends to OpenPNP, where either system's macro capabilities can be used to tailor the workflow to specific needs.
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Multi-MCU capabilities: Klipper can seemlessly integrate multiple controllers (for e.g. A main controller for the XY motors, a seperate controller for the Head with 3 motor drivers or any such esotric combination)
A collection of lessons learned, tools used and techniques employed to make this possible
- Everything to build a Lumen PNP. I purchased everything over a period of time and let it collect dust for several months. I probably should have just coughed up the dough to buy a kit from Opulo. But whats the fun in that. https://www.opulo.io/
- Bigtree tech Octopus max EZ https://github.com/bigtreetech/Octopus-Max-EZ
- Raspberry Pi 5 (8GB) https://www.raspberrypi.com/products/raspberry-pi-5/
- NVMe hat to attach a 256GB SSD https://www.adafruit.com/product/5845
- Misc hardware, nuts, bolts, stepper motors (salvaged from several ender 3 3d printers), LEDs etc
- Klipper firmware https://www.klipper3d.org/
- OpenPNP https://github.com/openpnp/openpnp
- Debian Linux distro
Installation of Klipper and OpenPNP is very well documented Refer to the respective installation guides to get familiar with installation process
- If you are building a P&P for a custom build, make sure you get a controller board that can support the number of steppers you intend to use
- I opted to mod the Lumen to use 2 motors each for the X and Y axis.
- Your build determines the Klipper configuration. This is obvious, but I wanted to make sure to pint that out. DO NOT blindly use my configuration.
- The details provided here are for documentation and refernce purposes only. No warranty is provided on any information provided here.
- I am running both OpenPNP and Klipper on the same Raspberry Pi 5. This is kinda important, and the main point of this use case. If you are running OpenPNP on a different device and Klipper on a different device, then you have lost the plot :)
- If you are building a 1 nozzle P&P, you may be able to use the official Klipper repo. Howver, I was building a 2 nozzle P&P. So I used a fork of Klipper that has support for XYZABC axis configuratoion.
- The fork i used is here : https://github.com/naikymen/klipper-for-cnc use (use the #pipetting branch)
- See the repo for the installation insdtructions : https://github.com/naikymen/klipper-for-cnc?tab=readme-ov-file#installation
- Official Klipper repo is here : https://github.com/Klipper3d/klipper
- There are several videos and sites which explain klipper installation, such as this writeup https://klipper.discourse.group/t/installing-klipper-with-kiauh/10734
- Build your firmware for the controller board you are going to use. Most boards that can be flashed with Marlin can also be used with Klipper. YMMV
Detail the configuration steps specific to getting Klipper and OpenPNP working together.
- Getting Klipper to talk to OpenPNP was surprisingly simple.
- OpenPNP can talk to a controller either using Serial (USB) or TCP
- Klipper provides a "virtual Serial port" that we can use, but we will use it over TCP
- Make sure you are able to run this command in a Linux bash shell
sudo socat TCP-LISTEN:23,reuseaddr,fork OPEN:/dev/pts/0,append - If you get any errors, try using
sudo apt install socatbefore you run the command - keep the terminal window open once you hit enter. This will keep the socket alive between Klipper and OpenPNP
- The config files along with all the macros are uploaded to this repo.
- The "HOME_ALL" macro has SET_KINEMATIC_POSITION A=0 and SET_KINEMATIC_POSITION B=0 because A & B axes are not "homed" axis. This resets the position at homing for those two axes. Also make sure to set "Force_Move" in the printer.cfg to enable it
- Setup is fairtly similar to other firmwares such as Marlin
- Klipper does not support all the G and M codes of Marlin, but there are equivalent commands that can be used.
- I have macros defined in Klipper for LED, Pumps and Sensor actuator turn on and off. In OpenPNP, you just have to use that macro instad of any G code based command. Example below
[gcode_macro BOTTOM_LED_OFF] gcode: SET_LED LED=bot_led RED=0 GREEN=0 BLUE=0 - So in the Actuator Regex, You would simply use BOTTOM_LED_OFF to define the turn off command
- Most of the OpenPNP solutions presented worked fine. Such as the G92 for Global Position Capture etc.
- For the Move command regex, OpenPNP suggested regex which includes the M204 command before the G1 command did not work. Easy fix was to remove everything before "G1" and save it. That will work like a charm
- Use the most simple motion planning system "Toolhead path" for now.
- Since we are not able to send Klipper M204 commands through OpenPNP, we are limited to this simple motion planning. If and when we figure out a way to sned the M204 command, higher order motion planning systems can be activated.
- #TODO post the machine.xml from OpenPNP
Explain how to use the system once it's configured.
Invite others to contribute and explain how they can do so.
Use at your own risk license :)
Embed images or videos showing the setup in action.