What Orca Slicer can and cannot do after a power cut
Orca Slicer is the slicing side of the workflow: it turns a model into G-code and can send that file through a supported printer or host integration, but it cannot recreate the firmware state or motor position the interruption erased.
On Klipper machines the roles are separate: Moonraker is the API clients use to talk to the printer, while Mainsail and Fluidd are web interfaces built on it (Moonraker documentation). They are not interchangeable Klipper hosts.
The pause tools are not recovery tools: in Klipper, PAUSE captures the current position so RESUME can return the toolhead, and SAVE_GCODE_STATE stores parsing state such as coordinate modes, offsets, overrides and the current XYZ and extruder positions (G-Codes). That state lives in host memory; nothing promises it across a restart or power cycle.
The config side is just as narrow: [pause_resume] captures and restores position with a recover_velocity for the return move, and [virtual_sdcard] prints a local file with standard SD commands such as M24 (Config reference).
Which situation are you actually in?
Situation | What survived | What to do |
|---|---|---|
Full printer or host restart | No live position or stored pause state; only the file and plate | Treat the print as stopped; do not resume blind |
Host stayed powered with a genuine pause | The captured pause position, if nothing restarted | Check position, adhesion and the toolhead first |
Vendor-documented recovery | The maker's documented procedure, if tested in advance | Follow that procedure exactly |
Do not assume every Klipper-based printer lacks recovery; some vendors document their own power-loss handling, so check your printer's documentation.
klipper-simple-power-loss-recovery is clearly third-party code whose README states it is not actively maintained (repository); it is not a Klipper module or an Orca Slicer feature, this is not an installation recommendation, and it does not replace checking position, homing or clearance.
What the screen and file do not tell you
A percentage is a progress readout, not a resumable cursor: continuing needs a known machine position and layer boundary, neither guaranteed after a power cut. A cooled bed can release the part, and de-energized motors can let the gantry drift or be bumped.
Klipper's historical discussion covers the physics: an ordinary supply lacks the energy to detect the failure, pause and record position, and a cooling bed and hot nozzle can damage the part within seconds (issue 2904). That was 2020, not proof that no recovery facility exists today.
Decision checklist before you touch anything
- Firmware and recovery facility. Which firmware is installed, and does the maker document a supervised recovery procedure?
- Restart status. Did the printer and host fully restart, or did the host stay up with a genuine pause?
- Adhesion and position. Is the part still stuck down, and is the toolhead where it should be?
- Mechanical clearance. Is there a blob, lifted edge or stringing above the last good layer, and clearance to move without hitting the part?
Unknown state means no blind resume: do not force the toolhead to an assumed position, bypass homing, or fake a starting point in G-code. Do not restart services or change configuration during another print.
The safe paths, in order
Prefer the procedure the maker documents, but only if it was configured and tested before the interruption. Otherwise restart the print. An advanced middle path: slice a measured remaining section and print it separately; it can work on simple geometry, but registration, the join and clearance limit it — a workaround, not a guarantee.
The browser G-code Analyzer is only for inspecting a sliced file locally, never a recovery controller. The exclude-object guide is an article explaining how a supported printer can skip a failed object; exclusion is a different task from reboot recovery, and neither restores state.
The completion check
End the failed job as your printer manual directs, then clear and prepare the plate as documented before a normal supervised new print from Orca Slicer. Do not send motion commands or attempt a blind resume with a partially printed object on the bed. If your checklist answers were uncertain, that clean restart is the recovery; a resume built on guesses is how a ruined plate gets worse.
