Move to Klipper

By using Klipper to drive multiple Arduino CNC shield, we can avoid:

• soldering parts.
• fixing our python interface to GRBL.

Klipper replaces GRBL, and will run on many more MCUs than the UNO.

Features to cover

• Double Y-axis:
  • "stepper_y1" will mirror the Y stepper, see this.
• Tool stepper control: https://gitlab.com/pipettin-bot/pipettin-grbl/-/issues/47#note_1213094953
  • Can be implemented as a manual stepper (without sync to other axes).
  • Implemented as a homeable-extruder: https://github.com/naikymen/klipper-homing-extruder
  • N-Axis machine: see https://gitlab.com/pipettin-bot/pipettin-grbl/-/issues/47#note_1213124359
• Probing: for tips and stuff https://gitlab.com/pipettin-bot/pipettin-grbl/-/issues/47#note_1178892093
  • Implemented custom modules: https://github.com/naikymen/klipper-homing-extruder
• Simultaneous XY homing: not happening
  • https://github.com/Klipper3d/klipper/issues/2299
  • https://klipper.discourse.group/t/fr-simultaneous-xy-homing/4954/
• Adapt code from protocol2gcode:
  • protocolBuilder: pipettin-grbl/klipper/code/piper/gcode.py
  • The Moonraker "commander":
    • See: pipettin-grbl/klipper/code/piper/coroutines_moon.py
    • The gcode list "writer" works for sending protocols and joystick moves.
    • The "safe" methods for sending protocols (i.e. with many checks) are a mess. Feedback and pauses not possible yet.
    • It worked well in the Jupyter notebook but I cant use task_create as a service for some reason.
    • Update position through the websocket.
    • Alternate usage: generate the GCODE and "print it" on Mainsail.
  • Implementation based on GCODE generation, and relying on Mainsail for streaming.

Caveats

The main caveat is that "Klipper is a 3D-printer firmware". This effectively means that there is no intention of supporting non-3D-printer CNC features.

For example, Klipper does not support:

• Probing in any direction (only -Z apparently).
  • Patch: use manual steppers for all axes, with the SYNC=0 option.
• Homing a "synchronized" stepper (i.e. "extruder homing").
  • Patch: Run-out filament sensor hack.
• Retraction after homing: https://github.com/Klipper3d/klipper/pull/5506
  • Patch: manual move and set position.

General patches:

• Macros.
• Sending low-level commands directly: https://gitlab.com/pipettin-bot/pipettin-grbl/-/issues/47#note_1216271485
• Make yet-another-klipper-fork

People

• Have a chat with Homer Sajoina from Friendzymes / GOSH colony picker.
• Folks at the Jubilee Discord are awesome: https://discord.com/channels/627982902738681876/741364565950070935