K2 OpenKlipper

An experimental, community-oriented upstream Klipper stack for the Creality K2 Plus. It preserves the K2-specific MCU protocols needed for PRTouch, Z alignment, motor RS485 control, fan feedback, and CFS operation.

The first public snapshot, v0.1.0-alpha.1, is based on the live-tested v62 build. It is for developers and experienced K2 owners who can recover their printer if testing fails. It uses this dedicated open control plane:

• Klipper API socket: /tmp/klippy_uds
• Moonraker: port 7126
• Mainsail 2.18.2: port 4409
• Legacy Fluidd/Moonraker retained for rollback: ports 4408/7125

Creality master-server and Monitor are disabled because both can issue printer-control commands. The stock touchscreen control plane is consequently unavailable. Passive Creality Wi-Fi, camera, audio, app, web, and upgrade services are left intact.

Project status

The live K2 has completed:

• X/Y/Z homing with the open PRTouch implementation
• nozzle wipe and second precision PRTouch Z home
• adaptive bed mesh
• post-mesh movement to the purge bucket
• CFS print-start purge
• transition into the sliced first layer
• 32% of the current Benchy without MCU timing errors or toolhead stalls at the saved validation point

This is an alpha release, not production firmware. A full long-duration print has not yet completed on v62. CFS works on the development K2, but its electrical interface and portability to other printers are not yet validated. PRTouch currently stops Z through the K2 hardware PA15-to-PC7 signal and native Klipper trsync; the in-tree host classifier is experimental fallback work.

See PROJECT-STATUS.md for the validation matrix and release gates.

This remains experimental printer firmware. Supervise initial prints, keep the stock rollback path available, and do not switch Klipper builds while a job is printing or paused.

OrcaSlicer

Use:

START_PRINT EXTRUDER_TEMP=[nozzle_temperature_initial_layer] BED_TEMP=[bed_temperature_initial_layer_single] TOOL=[initial_no_support_extruder]

Replace Creality's legacy Change filament G-code with:

G90
G1 Z{max(z_after_toolchange, 0.6)} F600

The full explanation is in config/ORCA-K2-PROFILE.cfg.

Repository layout

• config/ - K2 configurations and Orca profile notes
• klippy/ - pinned Klipper host code plus K2 integrations
• system/ - Mainsail, Moonraker service/configuration, compatibility patch, and Creality service isolation
• tools/ - release deployment helper
• OPEN-STACK.md - architecture, fixes, backups, rollback, and live evidence
• K2-BUILD-MANIFEST - exact upstream and integration commit provenance
• docs/PROJECT-STATUS.md - readiness and validation matrix
• docs/CFS-PROTOCOL.md - current CFS wire and state-machine findings
• docs/PRTOUCH.md - current PRTouch architecture and open questions
• CONTRIBUTING.md - safe ways to test and contribute

Help wanted

• validation on other K2 Plus firmware and hardware revisions
• CFS electrical, addressing, and cold-boot findings
• separation of the generic CFS protocol from K2 motion and sensors
• non-blocking serial transport for CFS polling
• PRTouch repeatability data across clean and contaminated nozzles
• completed long-print and recovery testing

Use the issue templates and include exact versions, logs, and the phase being tested. Do not publish credentials, serial numbers, Wi-Fi details, or other private data.

Important limitation

The bundled Moonraker is Creality's firmware package. Its Klipper and Moonraker self-updaters are deliberately disabled because the appliance lacks their updater metadata, Git client, requirements files, and build toolchain. The Mainsail web client can still update independently.

License

The Klipper-derived code is distributed under GNU GPLv3; see COPYING. Bundled third-party components retain their upstream copyrights and licenses. See THIRD_PARTY.md, K2-BUILD-MANIFEST, and system/mainsail/release_info.json.