[FR] feedrate option for FILAMENT_UNLOAD_PURGE_LENGTH

[rado79]

Description

first of all i realy enjoy the ADVANCED_PAUSE_FEATURE (Bowden)
would be helpful to make an option to set a feedrate for: FILAMENT_UNLOAD_PURGE_LENGTH

Feature Workflow

feedrate for FILAMENT_UNLOAD_PURGE_LENGTH is DEFAULT_MAX_FEEDRATE E:

// Quickly purge
do_pause_e_move((FILAMENT_UNLOAD_PURGE_RETRACT + FILAMENT_UNLOAD_PURGE_LENGTH) * mix_multiplier,
planner.settings.max_feedrate_mm_s[E_AXIS] * mix_multiplier);

would be nice to have a configurable feedrate in cofiguration_adv, because if using high extruder feedrate, acceleration and high torque on stepper - DEFAULT_MAX_FEEDRATE E0 is harmful to bowden, fittings, filament, gears,... - in case of hardened Filament in heatbreak after retract and 5 seconds pause.

[rado79]

my provisional solution:

pause.cpp
// Quickly purge
do_pause_e_move((FILAMENT_UNLOAD_PURGE_RETRACT + FILAMENT_UNLOAD_PURGE_LENGTH) * mix_multiplier,
(PAUSE_PARK_RETRACT_FEEDRATE) * mix_multiplier);

[yet-another-average-joe]

The filament must harden in the heatbreak, and then be pushed + retracted as fast as possible in order to ram purge, or it will not be ram purging.

Doing this at PAUSE_PARK_RETRACT_FEEDRATE will do nothing special, as the filament will have time to melt again. It is simpler to set FILAMENT_UNLOAD_PURGE_RETRACT and FILAMENT_UNLOAD_PURGE_LENGTH to zero (deactivate ram purging).

But having "FILAMENT_UNLOAD_PURGE_FEEDRATE" and "FILAMENT_UNLOAD_PURGE_ACCEL" parameters wouldn't hurt.

So, better add a parameter for feedrate in Configuration_adv.h, and pass it to do_pause_e_move().

(i too enjoy the ADVANCED_PAUSE_FEATURE)

[EDIT] I see it's been done while I was writing !

[rado79]

The filament must harden in the heatbreak, and then be pushed + retracted as fast as possible in order to ram purge, or it will not be ram purging.

Doing this at PAUSE_PARK_RETRACT_FEEDRATE will do nothing special, as the filament will have time to melt again.

i don´t like to go lower than 25-40mm/s. but if you use a very high extruder feedrate/acceleration for linear advanced, it would make sence to lower down to a normal default feedrate.
i think 21mm Filament (retract 13mm +purge 8mm) in less than a half second is stress to mechanics, makes filament curled between extruder and nozzle (bowden)

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label / comment or this will be closed in 5 days.

[rado79]

meanwhile integrated in the code