4.5 Firmware Retraction (Deprime)
This allows you to configure the printer with a filament retraction
setting (in units of steps) to be used when pauses occur, planned or
otherwise. You are able to separately control the right extruder, A,
and the left extruder, B. If your printer is only equipped with one
extruder, it is considered “A”.
When a deprime setting is non-zero, the printer will deprime the
associated extruder by the specified number of steps when it is
active and any of the following occurs:
- Pausing, whether user initiated or a P-Stop generated
- When the printing process is temporarily idle because the
queue of processed segments has run out. Depriming the
active extruder will help prevent blemishes.
- If “Deprime on Travel” is enabled, then, when the printer
detects a travel move it will deprime. However, it is difficult
for the printer to truly detect this, as the printing of very
low layer heights may require many short printing moves
which are not accompanied by extrusion. In actuality, the
printer can only identify travel moves if the print commands
disable the extruder stepper motor before effecting a move.
Note that most slicers do not disable the extruders before
a travel move, as it may allow the filament to back out of
the extruder by an unknown amount.
When printing resumes, the printer then feeds the filament back
in by the same number of steps by which it was deprimed.
By default “Deprime on Travel” is disabled, though deprime is
set to a non-zero value for each extruder as per Table 4.1.